Term
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Definition
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Term
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Definition
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Term
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Definition
staphylcoccus aureus
staphylcoccus epidermidis
staphylcoccus saprophyticus |
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Term
microscopic morphological apperarance of staphylcoccus |
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Definition
gram pos cocci
arrangement-irregular clusters
non spore formers
non motile
usually no capsule with the exeption of staphylcoccus aureus which has a capsule |
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Term
3 types of virulence factors for staph |
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Definition
toxins
enzymes
structural compenents toxins and enzymes are both extracellular |
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Term
name the 4 protein toxins associated with staphylcoccus |
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Definition
hemolysin
leukocidin
enterotoxin
toxic shock syndrome (TSST-1) |
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Term
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Definition
lyses red blood cells by disrupting cell membrane |
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Term
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Definition
lyses white blood cells by disrupting cell membrane
incapacitates the host's immune response |
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Term
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Definition
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Term
virulence enzymes assoc w/ staphylcoccus
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Definition
coagulase
fibrinolysin
hyaluronidase
lipase
penicillinase
catalase
exofoliatin or epidermoyltic toxin |
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Term
coagulase in staphylcoccus |
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Definition
plasma clotting protein; converts fibrinogen to fibrin
coats bacteria w/ fibrin and prevents phagocytosis
aids in attachment |
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Term
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Definition
digests fibrinogen (fibrin clots)
normally fibrogen is converted to firbin by coagulase (and the subsequent fibrin makes a clot)
clot on exterior surface inhibits phagocytosis and helps in attachment |
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Term
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Definition
spreading factor
digers hyaluronic acid (cememnt b/w cells) around host cells which promotes invasion and allows it to move from focal pt to other parts |
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Term
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Definition
degrades lipids
allows bacteria to colonize on oily skin |
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Term
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Definition
hydrolyzes penicillin
drug resistance
inactivates peniciate-what gorohea does
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Term
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Definition
degrades H2O2 (hydrogen peroxide)
toxic metabolite end product |
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Term
exfolitain or epidermolytic toxin in staph |
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Definition
protease that causes peeling of superficial skin layers by dissoliving intracellular bridges |
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Term
protein A as a virulence factor in staphylcoccus |
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Definition
structural surgace component virulence factor
surface component linked to peptidoglycan of call wall (of staph aureus); inhibits antibody mediated clearance of bacteria by binding to IgG (completes for IgGs binding site) |
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Term
lipoteichoic acid as virulence factors in staphylcoccus |
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Definition
binds to tissue components; cell adhesion
considered structural surface component in staph |
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Term
virulence factors/speicies identification of staphylcoccus aureus |
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Definition
coagulase positive
hemolysin (alpha toxin)
leukocidin
protein A
capsule |
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Term
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Definition
**Most resistant of all non spore formers
major pathogen of genus
carriage location-anterior nares, nasopharynx, skin
carriage rate-30 to 50 % of healthy adults |
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Term
toxins of staphylcoccus aureus |
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Definition
blood cell toxins
intestinal toxins
epithetlial toxins |
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Term
blood cell toxins of staphylcoccus aureus |
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Definition
hemolysins-hemolytic, have a clearing around the colony
leukocidins |
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Term
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Definition
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Term
epithelial toxins of staph aureus |
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Definition
exofoliatin or epidermolytic toxin
superficial peeling of skin
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Term
3 types of infections staph aureus causes |
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Definition
superficial infections
toxigenic infections
systemic infections |
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Term
toxigenic infections assoc w staph aureus |
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Definition
staphylococcal scalded skin syndrom (SSSS)
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Term
superficial cutaneous infections w/ staph aureus |
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Definition
pyodermic infections
pimples, boils, carbuncles, and impetigo |
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Term
characteristic symptoms of staph aureus superficial cutaneous infections
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Definition
pus formation,edema, pain, erythema, infection site has an absess formed (localized inflammatory reac-fibrin clot stops infection from spreading)
staphlococcus-pyogenic cocci
primary infection sites at face, back of neck, buttocks
risk groups- elderly and young children w/ poor personal hygeine
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Term
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Definition
sebaceous gland opening (skin opening)
hair follicle
wound/cut |
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Term
tx of staph aureus superficial infections |
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Definition
minor lesions self resolve-keeping area clean
surgical incision and drainage
chemotherapy-topical antibiotics-oral antibiotics ineffective |
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Term
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Definition
can happen with staph aureus
higher risk in diabetics |
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Term
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Definition
young children usually
staph auerus subcutaneous infection |
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Term
Staphylococcal scaleed skin syndrome (SSSS)\ |
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Definition
exfolitan or epidermolytic toxin
separates epidermal layer from derms-blistering and peeling of skin-exposes red under layer
general appearance of burned skin |
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Term
mode of infection of SSSS |
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Definition
syndrome begins as an erythema around the mouth and nose
spreads rapidly to infect skin of neck, trunk, and extremities |
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Term
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Definition
risk group with infants and young children < 4 years (neonatal infection)
primary infected sites include umbilical cord and eyes-low mortality rate
death can occur as secondary infection of the denuded skin by other bacterial pathogens
tx-topical antibiotic mupirocin |
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Term
Toxic Shock Syndrome (TSS) |
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Definition
infection from cellulose based tampons
had toxic shock syndrome toxin-1 (TSST-1)
death 2-5% from respiratory failure
can be prevented by removal of cellulose based superabsrobent tampons from market in 1980 CDC recomends that tampons are not used continously during a menstrual cycle
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Term
mode of infections of TSST-1 |
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Definition
absorb and make low MG++ levels
inc growth bacteria of staphylcoccus aureus
triggers TSST-1 which is absorbed into the blood stream
TSST-1 (super antigen) stimulates T lymphocytes to produce cytokines intravenously resulting in endothelial cell damage-shock and multisystem failure |
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Term
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Definition
inital symptoms of high fever, vomitting, diarrhea and muscle cramps (myalgia)
ten days later-hands and soles of feet develop sun burn like rash which means peeling of skin, all over body and even tongue
severe sx-shock and multi-organ system failure |
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Term
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Definition
fluid replacement and chemotherapy |
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Term
toxigenic gastrointestinal disease-food poisoning (food intoxication) staph aureus |
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Definition
food handler contaminates, staphylcoccal lesions of skin (hands and nasopharyngeal carriers)-contaminates food-food left unrefridgerated (KEY)-room temperature growth of S. Aureus-production of enteriotoxin (func to disrupt GI tract) |
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Term
virulent feature of food poisoning |
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Definition
enterotoxin heat stable-not inactivated by digestive enzymes
toxin production does not alter food taste or smell
disrupts gastrointestinal lining |
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Term
symptoms, recovery food poisoning |
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Definition
sx start in 4-6 hours
vomiting,cramps, diareehea, nausea
self-limited 24-48 |
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Term
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Definition
dangerous because the microbes are carried to all body sites
bacteria reach site via
-focus of infection
-extensive surgery
-traumatic injuries |
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Term
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Definition
osteomyelitis (inflammation of bone)
pnemonia
endocarditis (inflammation of the endocardium)
meningitis (inflammation of the membrane surrounding the brain and spinal column
pyoarthritis-bacterial infection of joints |
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Term
risk factors involved w/ systemic infectiosn |
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Definition
pre condtion in an indiv; diabetees, burn wounds, extensive surgery, cystic fibrosis, cirrhosis of liver or those immunosuppressed or immunodefective in phagocytic properties |
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Term
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Definition
prolonged combination antibiotic therapy
drug regiment of 1 antibiotic, then another, then another, dec possibility of drug resistant strains |
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Term
coagulage negative staphylcoccus |
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Definition
do not form virulent clot
staphylococcus epidermidis
staphlococcus saprophyticus |
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Term
staphlyococcus epidermidis |
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Definition
normal flora
common inhabitiant
human skin, respiratory tract and mucous membranes |
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Term
Name the two coagulase negative Staphylcoccus |
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Definition
Staphylcoccus epidermidis
staphylcoccus saprophyticus |
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Term
staphylcoccus epidermidis |
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Definition
normal flora
common inhabitant human skin respiratory tract and mucous membrane |
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Term
route of infection of staph epidermidis |
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Definition
Iatrogenic infection
infections related to surgical procedures that involve the insertion of foreign bodies, artificial valves, catherters (UTIS), prothetic hips and AV shunts (endocarditis)
opprotunistic infection |
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Term
mode of infection/types of infections staph epidermidis |
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Definition
attachment of bacteria to foreign body
multiplication/colonization
types of infections include: endocardities, UTIS and wound infections |
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Term
staphylcoccus saptrophyticus
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Definition
part of normal flora
common inhabitant lower intestinal tract and vagina |
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Term
primary infection staphylcoccus saptophyticus |
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Definition
UTI, dysuria (pain in urination), pyuria (pus in urine), and high numbers of bacteria in the urine (should have zero in healthy urine)
2nd cause of UTI infections in sexually active young adolescent women |
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Term
differentiate b/w coagulase neg staphylcoccus
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Definition
bacterial sensitivity or resistance to antibiotic novobiocin
staph epidermidis-sensitive
staph saphtophyticus-resistant |
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Term
prevention of staphylcoccus infections |
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Definition
no vaccine is available
minimize opprotunity for infection
hygeine (hand washing)
adequate cleansing of wounds; change bandages frequently
attention to indwelling devices (catheters and needles)
tx surfaces w/ disinfectants |
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Term
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Definition
clinical presentation of px
isolation and demonstration of bacterium from clinical specimans (skin scrapings, blood, pus)
a. gram stain
b.innoculation of media
blood agar-enriched media with hemolytic pattern and colony color,
mannitol salt agar, selective medium (additive 7.5% NaCl), differential medium (fermentation of mannitol; monitor change in pH)
biochemical tests such as catalase tests and coagulase tests |
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Term
Nosocomial staph infections |
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Definition
neonates and surgical px
secondary transmission from "carriers" in hospital
carrier rate of staph aureus in general population is 30%
carrier rate of staph auerues in hospital pop is 70-80%
emerging superbug is methicillin resistant staph aureus or multiple resistant (MRSA) |
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Term
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Definition
health care associated (hospitals, nursing homes, dialysis center)
increased risk factors is older adults, weakened immune system, burns, surgical wounds, hospital stays and 10 days, invasive devices such as dialysis (catherterized) or feeding tubes, livnig in a long term facilitym recent antibiotic use |
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Term
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Definition
community associated MRSA
inc risk factors
daycare settings, NFL/NBA players, dorm residents, prisons, military training camps, gay men |
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Term
5 C's that make is easier for MRSA to spread/treatment |
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Definition
crowding
frequent skin to skin Contact
Compromised skin
Contaminated items
lack of Cleanliness
tx is vancomyocin w/ combo |
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Term
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Definition
Gram positive bacteria
oval/spherical in shape (cocci)
grow in pairs or chains
**catalase-negative (staphylococci are catalase +)
2h2o2 (catalse enzyme)→2H2O+O2
fastidious-require complex media for growth in lab (perferably containing blood)
most are faculative anarobes (grows both aerobically and anaerobically)
large heterogenous group of bacteria-includes 100 diverse species that can colonize skin and mucousal membranes (oral cavity, nasopharynx, upper Respiratory tract, GI tract, genitourinary tract)
some memebres are harmless commensals, some are involved in food production (ex swiss cheese) others are impressive human pathogens |
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Term
Pathogenecity of Streptococcus Genus |
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Definition
about 35 species have been identified aas sources of invasive disease in humans (ranging from local to systemic infections)
the most common human streptococcal pathogens, listed in order of prevalence and mortality are
1. S pneumoniae
2. S. pyogenes-group A Streptococcus (GAS)
3. S. agalacticide-group B Streptococcus (GBS)
4. Viridans streptococci (ex S. mutans) pathogenecity is definied as the degree of damage caused by both the microorganism itself and the response of the immune system to the pathogen |
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Term
streptococcal class system |
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Definition
attempts have been made to clinically identify strep by several class systems including
1. Lancefield group-serologic system based on reaction ofo specific antisera w/ surgace carb antigens
2.hemolytic pattern (RBC lysis) on blood agar plates (alpha, beta, gamma)
3. phenotypic traits (incl biochemical reactions w. antibiotic sensitivity)
4. molecular studies designating species and sub species |
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Term
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Definition
historically the classification of streptococci was based on the system developed by Rebecca Lancefield (1895-1981)
Strep strains were grouped according to the Carb composition on the cell wall antigens (but a strep can be pathogenic w/o one of these pathogens-just not lancefield patho)
there are 20 serotypes described as lancefield groupsA to V (exluding I and J) some strains are classified as "non Lancefield streptococci"
drawbacks to this approach include that the group-specific antigens may be absent b/w related strains or shared b/w distinct species
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Term
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Definition
S. pyogenes: Grp A Strep "GAS"
infections are pharyngitis, skin/ soft tissue infectiosn |
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Term
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Definition
S. agalactiae; Grp B strep "GBS"
infections are neonatal pneumonia, sepsis |
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Term
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Definition
S. mutans, mitis, salivarius, thermophilus, sanguinis
Infections; caries, endocarditis |
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Term
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Definition
S. pneumoniae
infections: pneumonia, meningitis, otitis media (middle ear infection), sepsis |
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Term
alpha hemolytic streptococci |
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Definition
give plate an army green hue
differentiate b/w species w/ optochin test
sensitive to optichin (has zone of inhibition)-S. pnemoniae
no zone of inhibition/no optochin sensitivity-viridans streptococci (ex. S. mutans) |
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Term
Beta hemolytic streptococci |
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Definition
leave clear or yellowish area on plate (from agar)
differniate b/w species by evaluating suceptibility to antibiotic bacitracin
zone of inhibition w/ bacitracin-S. pyogenes (group A strep) (GAS)
no zone of inhibition-bacitracin resistant-S. agalactiae (group b strep) (GBS) |
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Term
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Definition
no hemolyiss
lancefield antigen group d most important w/in gamma hemolytic strep
molecular methods have determined the most sig gamma hemolytic group d pathogens belong to a distinct genus, Enterococci
group D non enterococcal strep (same habitat, ex GI and GU tracts) can cause endocarditis, UTIs, and are assoc w/ colon cancers- S bovis subspecies group |
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Term
molecular methods strep classes |
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Definition
(16s RNA) designate 6 groupings
***See chart in strep lecture** |
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Term
important points about S. pneumoniae |
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Definition
- alpha hemolytic
- optochin sensitive
- not lancefield classified but still pathogenic
- sig global cause of illness and death-particularly amoung children and elderly; responsible for 1.6 million deaths a year in children under 5
- commonly colonizes in human nasopharynx esp of children-disease is rare (90% of children colonized by age 5; up to 40% of adults-prescence doesnt mean dx state)
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Term
pneumococcal pathogenesis and virulence |
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Definition
- at beginning of 20th century, killed more ppl worldwide than any other bacterial pathogen
- today is most common bacterial cause of acute respiratory infections (sinusitis, pneumonia, and otitis media (middle ear infections))
- intermitent inhabitant of healthy human nose and throat (nasopharnx)
- transmitted person to person via respiratory droplets
- colonization does not usually rseult in dx however strains are typically carried asymptomatically for weeks to months
- however devastating consequences may result when organism gains access to lung, blood, or CSF
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Term
pneumoccal virulence factors |
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Definition
many cell molecules play a role in pneumococcal pathogenesis and virulence
2 promininent virulence factors
1. pneumolysin-secreted cytotoxin that lysis cells and damages tissues
2. polysaccharide capsule |
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Term
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Definition
***most important determinant of virulence-non encapsulated strains=no invasive dx
greater than 95 capsular serogroups identified to date-serotyping system is based on antibody reactions to capsular antigens, known as quelling reaction
13 serogroups responsible for majority of human dx
protects against phagocytosis
basis of pneumoccocal vaccines |
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Term
pnemococcal infections and disease
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Definition
clinical dx depends on site of infection and severity of infection and are classified as
1.non invasive-otitis media, sinusitis, non bacteremic pneumonia-in lungs, not blood stream
OR 2.invasive-bactermic pneumonia, meningitis, in lungs AND blood stream |
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Term
Otitis Media from Non invasive Pneumococcal disease
**what is special about this infection? |
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Definition
**most common pneumococcal infection
primarily affects young children
usually follows a viral URI
sx-acute onset severe pain, fever, loss of hearing, swollen red and bulgin tympanic membrane
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Term
sinusitis from non invasive pneumococcal disease |
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Definition
complication of URIS
often presents w/ facial pain, congestion, fever, and a persistent nightime cough |
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Term
invasive pnemoccocal diseases |
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Definition
follows an infection of a normally sterile body fluid (ex blood, CSF), and can be life threateneing
include pneumonia, meningitis, and other invasive syndromes |
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Term
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Definition
most common serious pneumonoccocal disease***
diag by gram staining and culture of sputum-gram pos cocci
considered invasive when blood cultures are also positive |
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Term
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Definition
s. pneumoniae and neisseria meningitis are the most common causes of meningitis in children and adults
20% mortality even w/ antibiotic therapy
50% of survivors have permanent complications including deafness, mental retardation, personality changes, seizures |
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Term
other invasive pneumoccocal disease syndroms |
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Definition
can involve virtually any body site ex-spread via bacteremia and include osteomyelitis, septic arthritis, endocarditis, etc |
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Term
dx and tx of pneumoccal disease |
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Definition
optimally: collect body fluid from site of infection by sterile technique
in case of non invasive dx, presumptive tx is often initatied after meeting diagnositc criteria
examine fluids by gram staining, culture, capsular antigen assay, and or PCR
tx w/ approp anitbioitics and dosages dependent of type and severity of disease |
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Term
preventing pneumoccocal diease w/ vaccination |
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Definition
2 vaccines avail in US
1. PCV-13-developed specifically for infants and yound children, includes 13 capsular serogroups that caused most invasive dx and had most antibiotic resistance in this age froup
resulted in more than 90% dec in vaccine serogroup invasive dx
however-resulted in inc colonization w/ (and disease due to) other serogroup expressing strains
2.PPV-23 recommened for ppl over 65 years old and those 2-64 w/ underlying medical conditions
not as protective as PCV-13, lasts only about 5 years
relatively effective against invasive pneumoccocal dx
improved pneumoccocal vaccine formulations needed for adults |
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Term
other pneumoccocal dx prevention strategies` |
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Definition
prevention and/or control of illnesses that predispose to pnemoccocal dx including flu vaccine, management of diabetes, heart and lung dx, HIV
reduction of antibiotic misuse-resistance prepetuates organism transmission and dx in the community |
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Term
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Definition
only species in Lancefield's group A (GAS)
Beta hemolytic
bacitracin sensitive
cause a variety of important human dx ranging from mild superficial skin infections to life threatening systemic diseases (est 700 million infections occur worldwide each year, although the overall GAS infection mortality rate is .1%>650,000 of the cases are severe and invasive w/ a mortality rate of 25%) *dont memorize this exact number in stats
infections typically begin in the throat or skin |
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Term
pathogenesis and virulence of Strep Pyogenes |
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Definition
colonization is infrequent and GAS is often pathogenic when present-if its there, you have it
can cause both pyogenic/suppurative (assoc w/ local bacterial mult and pus formation) and non pyogenic/non supportive syndromes (past infections/autoimmune syndromes)
produce a large # of products that contribute to the organisms pathogenesis
together the panel of GAS virulence factors allow the organism to attach to host tissues, evade the immune response, and spread by penetrating the host tissue layers |
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Term
major GAS virulence factors |
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Definition
1. M Protein-major protein coating the cell surface, greater than 100 antigenically distinct types, contributes to resistance to phagocytic killing
2.hyaluronic acid capsule-not produced by all strains, protects against phagocytosis, weak immunogen (similar to hyaluronic acid on connective tissues), considered weak because we already have host antigens that are similar, immune response means autoimmune disease
3. many extracellular products including cell membrane damaging toxins streptolysins S and O (cause Beta hemolysis phenotype), streptococcal pyrogenic exotoxins (SPEs) A, B, C are linked to rash and severe invasive infections, proteins that enzymatically inactivate critical components of the host immune response (ex C5a peptidase, ScpC, streptodornase) |
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Term
GAS infections and diseases |
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Definition
s pyogenes infections span the spectrum from mild to life threatening
non invasive GAS infections tend to be less severe and more commmon, these usually are effectively treatred with antibiotics
invasive GAS infections tend to be more severe and less common, these ocur when S pyogenes infects normally sterile areas (ex blood and organs), all severe GAS infections may lead to shock, multiorgan failure, death
spread by person to person contact |
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Term
strep throat and s pyogenes |
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Definition
pharyngitis
affects all ages but one of the most common bacterial childhood infections
typically resolves in 3-5 days, tx given primarily to prevent spead and complications
has suppurative complications and non suppartive complications |
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Term
suppartive complications of strep throat |
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Definition
result from spread of organism from the throat mucose to other tissues and the bloodstream
inlcludes; sinusitis, endocarditis, otitis media, bactermia, pneumonia, meningitis |
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Term
non supportive complications of strep throat |
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Definition
autoimmune complications that can appear several weeks after initial strep infection and can include
acute rheumatic fever (characterized by inflammation of the joints and heat following strep throat)
and acute post infectious glomerulonephritis inflammation of the kidney (renal glomerulus) following throat or skin infection |
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Term
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Definition
less common non invasive strep A infection involving strep throat (usually) accomp by a characteritic "sandpaper" body rash and "strawberry tongue"
caused by release of SPES-streptoccocal pyogenic exotoxins |
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Term
GAS and skin and soft tissue infections
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Definition
can cause a variety of infections of the skin, subcutaneous tissues, muscles, and fascia
impetigo-localized skin infect preventable by adequate hygeine, colonization of skin precedes infections, scratch, insect bite, tattoo etc inoculates organims into the skin
erysipelas and cellulitis is a mult and lateral spread of s pyogenes onto and into deeper layers of skin and subcutaneous tissues (fat=cellulitis), involves a skin rash infection of the upper layers of the skin which becomes bright red, tender, and raised (orange peel texture) |
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Term
Necrotizing fascilitis (NF)-"flesh eating dx" |
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Definition
rare-bacteria invade and mult in the deeper layer of the skin, subcutaneous tissue and fascia
s pyogenes cause about 60%
usually begins @ site of trauma through which organisms are introduced into deeper tissue, usually from organisms residing on skin ex following minor trauma but can also originate from the bowel ex following abdominal surgery
severe dx of sudden onset, rapid progression, and requiring aggressive tx w/ surgical debridement and IV antibiotics
mortality rates about 75% if left untreated |
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Term
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Definition
presence of bacteria in blood
GAS bacteremia usually assoc w/ local infection (ex throat, skin, pneumonia, NF)
occasionally infectious complication of childbirth "puerperal sepsis"-once most common cause of maternal mortality
primary mech of bacterial spread to internal organs "hematogenous dissemination" can result in endocarditis or meningitis
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Term
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Definition
streptococcal toxic shock syndrome
typically presents in ppl w/ preexisiting GAS skin infections that have developed bactermia
caused by release of SPEs into bloodstream
sudden onset of high fever, dec blood pressure, malaise, confusion, and rapid progression into coma and mult organ failure
mortality greater than 30% early recog critical for px to recevie aggressive medical intervention and antiobiotic therapy |
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Term
prevention and tx of GAS dx |
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Definition
no vaccine against GAS is currently avail
once GAS is documented as the cause of infection, antibiotic tx should be started promptly, dec incidence of invasive dx and both rheumatic fever glomeronephritis
for necrotizing fascitis, surgery is often also needed to remove damaged tissue and stop spread of infection
s. pyogenes infections are best prevented through effective hygeine (hand washing) |
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Term
important points to remember about S agalacitae (group B strep) |
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Definition
beta hemolytic
bacitracin resistant
belong to lancefields group B strep GBS
major cause of sepsis and meningitis in human newborns
cause of dx in healthy adult women related to pregnancy and childbirth
cause of invasive infections in adults with underlying chronic illnesses |
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Term
GBS virulence factors and pathogenesis |
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Definition
GBS strains that cause human disease express a capsular polysaccharide (there are 10 serogroups)
GBS capsule is most important virulence factor
anti capsular antibodies protect only against GBS w/ the same capsule type (serogroup specific) (type 1-only against type 1 in the future) |
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Term
Early onset GBS infections in newborns |
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Definition
occur w/in first week of life, 50% have infection signs at birth
infections occur during deliver from colonized in maternal genital tract (up to 40% of women are naturally colonized with GBS)
50% of infants born to colonized mothers also becomes colonized-1 to 2 % actually develop infection
infection presents as neonatal sepsis with respiratory distress-100% infants bacterimic, 50% have pneumonia, 33% have meningitis |
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Term
late onset GBS infections in infants |
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Definition
occurs in infants 1 week to 3 months old
organism aquired during delivery or during later with colonized mother or hospital personale
meningitis most common presentation
infants may also have fever, seizures, bactermia, ostermylitis |
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Term
GBS infections and dx in adults |
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Definition
majority of adult GBS infections in otherwise healthy adults related to pregnancy and childbirth-peripartum fever may involve endometritis, bactermia, meningitis, endocarditis
infections in other adults (non pregnancy related) involve the elderly or those with chronic illnesses (ex diabetes, cancer) often develops cellulitis, soft tissue infections ( diabetic skin ulcers), UTIS, pneumonia, septic arthritis, endocarditis |
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Term
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Definition
prompt dx and initiation of antimicrobial therapy is critical |
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Term
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Definition
In US all preg women colonized w/ GBS tx'd prophylacticaly w/ antibiotics during delivery, women are screened by culture at 35-37 weeks of pregnancy, women w/ other risk factors also tx'd in absence of culture data (preterm delivery, prolonged labor, fever during delivery)
GBS vaccine in early stages but not yet avail, transplacental passage of maternal antibodies is protective for newborns, phase 1 trials of capsular vaccines suggest safe progess is being made |
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Term
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Definition
large groups of commensals, typically alpha hemolytic, some non hemolytic
differentiated from s pneumoniae based on optochin resistance and lack of polysaccharide capsule
lack lansfield antigens
predominantly inhabit the mouth
important agent in dental carries and endocarditis |
|
|
Term
patogenesis and virulence and Viridans |
|
Definition
|
|
Term
preventing dx with viridians |
|
Definition
|
|
Term
|
Definition
perfingens-cause gangree, food poisoning
difficile-causes ulcerative colitis
tetani-tetanus
botulium-botulism |
|
|
Term
microscopic morphological appearance of Clostridium |
|
Definition
gram postiive bacili
spore formers-spores eaten or contaminate injured skin
most are obligate anaerobes
most are motile |
|
|
Term
growth conditions of clostridium |
|
Definition
thioglycollate broth-anarobic growth (bottom of the tube)
litmus milk (curd formation)-stormy fermentation-plug, blows cotton out from gas production
blood agar-double zone of hemolysis-complete around initial colony then partial lysis
egg yolk agar-Beta lecithinase/a-toxin-turns plate white color, these degrade lecithin |
|
|
Term
|
Definition
histotoxic clostridia-C. perfingens
enterotoxic clostridia-C. perfingens and C. difficile
Cloistridum tetani
Clostridium botulinum |
|
|
Term
Histotoxic Clostridia/gas gangrene |
|
Definition
causitive agent is C. perfingens type A (spores found in soil)
opprotunistic pathogens that require a special enviro to initiate growth
traumitized tissue-lasceration, crush wound etc
vascular damage-impaired blood supply
necrotic tissue-dead, not receiving oxygen (anaroebic bacteria)
decreased oxygen |
|
|
Term
C perfingens produces a large number of exotoxins and extracellular enzymes such as |
|
Definition
collagenase
proteinase
deoxyribonuclease
most advantagous***a toxin-phospholipase C-lecithinase-disrupts membrane of host cell
Theta toxin-hemolysin-lyses RBC's |
|
|
Term
Cloistridial wound infections |
|
Definition
A. anaerobic myonecrosis-gas grangrene ***more sever
B. Anaerobic cellulitis |
|
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Term
|
Definition
infection of dead tissue, expands to healthy, ever widening of expansion of necrotic lesion adjacent to healthy muscle tissue
sx are local edema, action of a toxin-destruction of cell membranes
gas production-H2 and CO2-ferment carbs
change of skin color to black from dec blood supply
generalized fever
pain in infected tissue
example of this is road kill |
|
|
Term
risk group factors of anaerobic myonecrosis |
|
Definition
traumatic injuries-wars, car injuries
surgical procedures in close proximity to intestinal microflora, bowel surgery, abortions
elderly-poor circulation |
|
|
Term
covalescnece/immunity to anaerobic myonecrosis
|
|
Definition
no host defense
phagocytic cells useless
repeated infections do not produce immunity |
|
|
Term
treatment of anaerobic myonecrosis |
|
Definition
removal/debridement of dead tissue
application of antiserum (polyvalent antitoxin)
broad spectrum antibiotic-penicillin or tetracylcine
hyperbaric O2 chamber (inc O2 level) |
|
|
Term
|
Definition
localized infection of necrotic muscle tissue only-does not spread to healthy tissue
sx-similar to anaerobic myonecrosis but of a lesser severity |
|
|
Term
|
Definition
food poisoining
causitive agent C perfringens type A
second most common food poisioning worldwide |
|
|
Term
enterotoxic clostridia (c perfringens food poisoning) mode of infection |
|
Definition
ingestion of viable vegetative cells
synthesis of enterotoxin in SI
enterotoxin produced which breaks down intestinal mucosa-leakage of plasma membrane-disruption of osmotic equilibrium
spores in foods, germination, ingest cells, positive enterotoxin in SI, disrupts osmotic equilibrium |
|
|
Term
sx of enterotoxic clostridia and covalescence/immunity (food poisoning) |
|
Definition
watery diareha, abdominal cramps
no immunity, repeat attacks |
|
|
Term
control and prevention of enterotoxic clostridia |
|
Definition
cook food thouroughly intially-destroys spores
food refrigeration after prepartation-prevents enterotoxin production
reheating food-destrots toxin
spores-121 deg C
bacteria-100 deg C
toxins 80 deg C |
|
|
Term
exterotoxic clostridia-antibiotic assoc colitis |
|
Definition
causitive agent- C. difficile, drug resistant normal flora of intestine, antibiotic therapy disrupts normal flora of intestine allowing a superinfection or secondary infections with C. difficile (endogenous infection) |
|
|
Term
mode of infection of pseufomembranous colitis |
|
Definition
antibiotic therapy
colonization of intestine by C difficile
toxins produced-injure intestinal lining by inhibiting protein synthesis, produces hemorhaggic necrosis
leukocyte infiltration into colon due to toxin production
pseudomembrane-white patch on colon-micture of fibrin, mucous, leukocytes and necrotic epithelial cells (due to inhibition of protein by toxin)
|
|
|
Term
sx/ risk group/ and tx of C diff |
|
Definition
sx are abdominal pain, watery diareha, nausea,
risk groups are px receiving antibiotic therapy, primarily a dx of antibiotic induced colitis in hospitalized px
tx is discontinue antibiotics, maintain fluid, electrolyte balance, admin vancomyocin |
|
|
Term
Clostridium tetani (tetanus) |
|
Definition
generalized tetanus-initial involvement of neck and jaw muscles with progression to large muscle groups
neonatal tetanus-inital infection of umbilical stump, progression to generalized tetanus |
|
|
Term
conditions for infection of C. tetani |
|
Definition
favor spore germination
small puncture wounds
necrotic tissue at wound site
decreased O2
poly microbic infection-strict anaerobe, grows w/ faculative anaerobe dec level at that site, inc its ability to infect |
|
|
Term
variety of toxins produced w/ C tetani |
|
Definition
neurotoxin-tetanospasm or spasmogenic toxin-toxin of primary importance accounts for classic sx
site of action-targets neurons in the spinal column
function is to bind to gangliosides in the neural tissue-blocks release of neuroinhibitor glycine-continual contraction of muscles (tetany)
neural tissue plus glycine (neuroinhibitor)-prevents muscle contration; when tetanospasmin blocks glycine-continual contraction occurs
|
|
|
Term
|
Definition
initial-cramping and twitching of muscle around wound
later-sweating, pain around wound area, lockjaw or trismus-clenching of the law, muscle stiffeness neck and jaw muscles, risus sardonicus, sarcastic grin, opthotonos, arching of the back, want to keep external stimuli to minimum
extreme sx-preogression to other muscle groups, violents spasms of trunk and back-bone fractures
death can occur by paralysis of respiratory muscles |
|
|
Term
|
Definition
elderly, IV drug abusers, infants-neonatal tetanus (tetanus neonatorum) |
|
|
Term
convalescene/immunity tetatnus |
|
Definition
no innate immunity, repeated infections do not produce immunity, small amount of toxin in the circulation, toxins strong affinity for neural tissue, convalescence-no permanent damage to muscles |
|
|
Term
|
Definition
debridement of necrotic tissue
anti-toxin (only with free toxin-once bound-nothing to be done)
unimmunized-heman tetanus immune globulin (TIGH)-passive immunization
immunized-receive DPT series, may require a booster shor of tetanus toxoid**worlds most preventable disease
antibiotics-metronidazole or penicillin
anti-spasmic drugs or muscle relaxants-phenobarbital or chlorpromazine
|
|
|
Term
Clostridium botulinium (botulism) |
|
Definition
neurotoxins A, B, E, and F-human dx
Neurotoxin A-(neurotoxin-hemagglutinin)
func of hemagglutinin-prevents deactivation of neurtotoxin by gastric enzymes and lowered pH of stomach |
|
|
Term
|
Definition
food borne botulism
infant botulism
wound botulism |
|
|
Term
food borne botulism (food poisoning or food intoxication)
***what is significant about the botulinum toxin? |
|
Definition
mode of infection by ingestionof poorly preserved food containing Botulinin (botulinum toxin)
spores not killed
improper preservation created ideal enviro for spores to germinate
-anaerobic enviro, storage at room temp, alkaline foods (peaches, pears, more so than acidic tomatoes)
botulinin (botulinum toxin) product of metabolism
**most potent toxin-lethal dose 1 micro gram
toxin absorbed in GI, lymphatics and circulation, binds irreverisbly to NMJ of skeletal muscle (toxic site of action) |
|
|
Term
Sx of food borne botulism |
|
Definition
early-GI disturbane
NM sx-first affect muscles of head-same as C tentani, blurred speech and double vision (diplopia), slurred speech (dipphonia), difficulty swallowing (dysphagia)
critical sx-descending paralysis w/ involvement of respiratory system fatal for 8% infected |
|
|
Term
covalescene/immunity, tx, control/prevention of food borne botulism |
|
Definition
cov/immunity-repeated infectionsdo not produce immunity, small amount of toxin in the circ, toxins have strong affinity for neural tissue
tx-polyvalent antitoxin therapy, stomach lavage and enemas
control/prevention-adequate food prevention-kill spores, heat all canned food, toxin inactivated at 80 deg C for 20 min |
|
|
Term
infant botulism
**how does immunizing the mother help? |
|
Definition
assoc w/ SIDS
flaccid paralysis of floppy head baby syndrome
ingestion of spores, dietary supplement honey, multiplies in colon due to immature state of neonatal intestine and flora
indicators-suck and gag reflex dec, drooling, head control lost
tx, antibiotic tx
contol prevention-vaccinate preg females-passive immunity mother to child |
|
|
Term
|
Definition
rare neuroparalytic disease
spores enter a puncture wound-in vitro toxin produced
sx similar to food borne botulism
risk group is IV drug abusers |
|
|
Term
|
Definition
family of bacteria that primarily reside as normal flora on mucosal surfaces
most sig human pathogens of this genus are Neisseria meningitis, a cause of septicemia and meningitis and neisseria gonorrhoeae
|
|
|
Term
3 opprtotunistic pathogens of Neisseria |
|
Definition
N. lactamica
N. cinerea
N. polysaccharea |
|
|
Term
Normal flora Neissera species (5)
|
|
Definition
N flava
N subflava
N mucosa
N flavescens
N sicca |
|
|
Term
General charcteristics Neisseria |
|
Definition
gram neg diplococci
fastidious growth requirements-grow optimally at 37 deg C in 5% CO2, require highly enriched media
fragile, do not survive well in hostile growth conditions, cold/hot temps, UV lights, dry/arid conditions |
|
|
Term
Key points to remember about Neisseria |
|
Definition
N meningitidis may be transient to normal flora-can have in back of throat and be perfectly healthy whereas prescnene of N gonorrhoeae is pathogenic/disease state
N meningitis infections: low prevalence but high mortality whereas N gonorrhoaeae infections high prevalence byt low mortality |
|
|
Term
Neisseria meningitidis (5 important points to remember) |
|
Definition
1. Humans are the only natural host
2. colonize the URI
3. Transmitted via large droplets respiratory secretions
-10% healthy adult humans are colonized
-despite exposure/colonization few develop dx
4.life threatening cause of meningitis and sepsis
5.produce a capsule the primary virulence factor**** |
|
|
Term
meningococcal virulence factors (there are 3) |
|
Definition
Capsule is major virulence factor
undergo phase (ON/OFF) and antigenic (type/variety) variation
exhibit "molecular mimicry"-mimic human antigens-make it harder when mimics host |
|
|
Term
|
Definition
large struc polysacch layer surrounding the outside of the bacterial cell
protects against host immune factors and desiccation
important for invassive diseases
used to group N meningitis into 13 serogroups
serogroups A, B, X, Y, and W135 are the most pathogenic
may be immunogenic and elicit protective antibodies
|
|
|
Term
what is meningococcal disease |
|
Definition
caused by infection with N. Meningitis
results in a high mortality rate, even w/ tx
cause of life threatneing men and sepsis (blood infection)
meningitis: bacterial infection of meninges, the membranes that surround the brain and spinal cord
meningococcemia: bacterial infection of the blood/ other body organs, form of septicimia
men and meningococcemia are major causes of illness , death, and disability |
|
|
Term
transmission of N meningitis |
|
Definition
spread from person to person via direct contact with respiratory secretions, saliva, sputum or nasal mucus
requires close contact with an infected person/carrier including: kissing, sharing items that touch the mouth (drinks/eating utensils/cigs/chapstick), being w/in 3-6 ft of an infected person who is coughing and sneezing |
|
|
Term
risk factors n meningitis |
|
Definition
crowded living areas (dorms, baracks, prison)
not getting enough sleep (weakened immune system)
exposure to cig smoke (active or passive)
arid living conditions
alcohol use
viral URI
travel to endemic area (sub saharan africa and mecca)
compromised immune system-harder to fight off disease
|
|
|
Term
epidemilogy-1 N meningitis |
|
Definition
1. 6 of 13 capsuel serogroups cause human disease: A, B, C, X, Y, W135
2. MC cause sporadic disease, community outbreaks, large epidemics, 250 to 500k cases per year worldwide (inc if epidemic occurs), epidemics occur every 8-14 years in the african meningitis belt, about 500 to 1000 cases per year in the US (since 2005)
3. high case fatality rate (even w/ microbial therapy), children b/w the ages of 6 months to 4 years are highly susceptable
4.meningococcal disease usually presents clincially as one of 3 syndromes: meningiits (50%), bactermia/meningococcemia (37.5%) or bactermic pneumonia-can cause pneumonia(9%)
5.leading cause of bacterial meningitis in young adults 19-27 years old
|
|
|
Term
epidemiology 2 N meningitis |
|
Definition
epidemic outbreaks (ex african meningitis belt), primarily caused by serotype A followed by W135, C, X
sporadic outbreaks, caused by serotypes B and C followed by Y, W135, A
disease rates peak winter through early spring (dec through june), constant irritation of respiratory mucosa from dry enviro and colds
10-50% of infected people die despite receiving antibiotic tx
survivors often have permanent probs: loss of limbs, deafness and or blindness, mental retardation, strokes, seizures, behavioral issues/personality changes |
|
|
Term
clincial meningococcal disease |
|
Definition
following aspiration of N meningitis, bacteria may be elminated or colonize the nasopharynx
colonized indiv may remain asymptomatic "carriers" or develop a mild/moderate sore throat, pneumonia may develop, human nasophar only reservoir for MC (obligate human path), colonizing commensal of 3-25% of pop globally, correlates to 230 mill-1bill carriers worldwide, path of MC resembles the story of jekyl and hyde |
|
|
Term
jekyl and hyde side of meningococcal disease |
|
Definition
in some cases (less than 1%) the bacterai cross the mucosal barrier and enter the blood stream or CSF resulting in either
-mild disease-self limiting bactermic illnesses charac by fever and malaise sx resolve in 1-2 days
serious disease infection may progress to miningococcemia and/or meningoccocal meningitis |
|
|
Term
|
Definition
aka meningococcal septicemia
virulent N meningitidis invade into the bloodstream
sx are initially similar to fle infection including fever, nausea, headache, muscle/joint pain, chills, diareha, malaise
MC in the bloodstream results in an affre systemic response, small blood vessel damage results in small hemorrhages (petechiae), in severe infections further samage to blood vessesls can cause vascular collapse and large hemhorrages (purpura fulminans) |
|
|
Term
fulminant meningococcemia |
|
Definition
severe systemic infec charac by rapid circ collaspse and prog multi-organ failure
occurs in 5-15% of px w/ acute meningococcemia
abrupt onset of sx includes sudden appearance of widespread hemorrhagic skin lesions (hemorrhagic rash)
no signs of meningitis are typically presently-progressing so rapidly
very high concen of MC in the bloodstream
high mortalitiy (50%) w/in 12-24 hours of onset despite antibiotic therapy |
|
|
Term
|
Definition
most common outcome of MC disease
sx may include sudden onset of severe headache, high fever, malaise, chills, vomiting
progressive stiffness of the neck, back, and soldiers
neurologic issues are sensitivity to light (photophobia) and sound (phonophobia), altered mental status
convulsions, coma
petechaie or purpura may or may not be present
**rash is a big warning sign
10-25% of cases are fatal even w/ tx
survivors often have permanent damage seizures, deafness, MR, behavioral issues |
|
|
Term
|
Definition
positive sign of meningococcal meningitis when px's knee is flexed 90deg and attempts by px produce pain or resistance |
|
|
Term
brudzinski's sign of meningococcal dx |
|
Definition
pos if px hips and knees flex automatically when the examiner flexes neck |
|
|
Term
|
Definition
when meningococcal disease is suspected, tx must be immediately started and not delayed for confirmatory lab tsets
gold stand of dx is isolation of N men bacteria or DNA from either blood or CSF samples (both are normally sterile), diag relying on culturing organsims on chocolate agar plate followed by further testing to differentiate the species takes about 24-28 hours
NAATS (nucleic acid amplification tests) such as polymerase chain reaction (PCR) based assesments are now often used to identify the organism w/in several hours from hospital admittance
grams stain CSF shows gram neg diplococci (often inside neutrophils) can confirm dx and support initiation of immediate therapy
beside immediately tx'ing px, confirming etiology as an MC infection is important for the prevention of secondary cases and epidemiology (serogroup, antibiotic resistant profiles) |
|
|
Term
tx and prognosis of meningococcal disease |
|
Definition
potentially fatal medical emergency
prompt anitbiotic therpay is essential for survival
even with tx death or permanent disability often occur
preventative antibioitc tx, isolation, and or vaccination is necessary for close contacts of an infected person |
|
|
Term
prevention by vaccination |
|
Definition
majority of meningococcal disease in the us is caused by strains of producing capsular serogroups B>C>Y
Polysaccharide based meningococcal serogroup A, C, Y, and W135 vaccines are avail in US and have been recommended by the CDC for routine use snice 2005 for
-all adolescents aged 11-18; 1st dose at age 11-12 yrs, booster at 16-18, booster lasts 3-5 years
people 2 months-10 years old or greater than 19 if at high risk for mening disese, includes indiv w/ certain med conditions, (ex damaged/missing spleen, immune deficiencies), high risk living enviro, (dorms, barracks,) occupational exposure, travel to endemic area, control outbreaks if in close contact with dx case of MC disease |
|
|
Term
|
Definition
Serogroup B causes 30-50% MC cases
until recently there were no MC serogroup B vaccines liscened for general use in the US
b/w oct 2014 and jan 2015 the FDA approved 2 serogroup B MC vaccines (Trumemba, Bexaro) for use in US for people 10-25 years of age
these vaccines will be important tools for controlling outbreaks of serogroup B meningococcal disease
although there is no routine recommendation for serogroup B meningococcal vaccines at this time, 2015 is going to finalize these
|
|
|
Term
Neisseria gonorrhoeae
*capsule?
*viruclence factors?
*natural host? |
|
Definition
humans are only natural hose (obligate pathogen to humans)
higher prevalence, lower mortality
aquired by sexual contact
caustive agent of STI gonorrhea
affects mucous membranes of urethra, cervix, rectum, pharynx, and conjunctiva
high transmission rate
may cause disseminated disease and permanent damage
essentialy same virulence factors as N menin (LOS, OMPS, pillis) but NO CAPSULE |
|
|
Term
Epidemiology N. Gonorrheae-1
|
|
Definition
one of the oldest known human diseases
major public health problem
750,000 cases/year in the US (<1/2 reported)
ranks 2nd amoung communicable diseases in the uS
majority of infections are asymptomatic and therefore not reported and tx'd
new infections are ususally contracted from an infected sex partner with no or minimal sx
attack rates highest in 15-29 yrs, inc in older pop since 98 (viagra), but occurs all ages
infection not protective
transmitted person to person through infectious secretions
after 1 of sex w/ infected parter 20-30% men infected, 50-90% of women infected |
|
|
Term
clincial disease N. gonoreheae |
|
Definition
GC can be localized and systemic infections
untreated gonorrhea can cause serious and permanent damage and health probs in both men and women |
|
|
Term
|
Definition
acute urethritis (usually dev w/in 5 days), painful urination, purulent urethral discharge "the drip", localized inflammation (redness, swelling, heat, pain)
may be asymptomatic, asymptomatic males are important reservoir for transmission and are at inc risk for developing complications
untreated gonococcal infection: may resolve on its own, but most likley not before it is transmitted to a partner, GC may invade the prostate or testicles and cause infertility and/or become systemic |
|
|
Term
|
Definition
primary site of infection is cervix, but bacteria can be found in the vagina, urethra, and rectum
sx are often mild and non specific
more than 50% infected women are asymptomatic and receive no tx
inc risk of infecting a partner
severe health consequences if untreated-can progress to uterusm fallopian tube, ovaries; PID may develop, increased risk disseminated infection |
|
|
Term
|
Definition
generic term inflammation of uterus, fallopian tube, and or ovaries that leads to scar formation on nearby tissues and organs
bacteria ascend the reproductive tract infecting and causing inflammation of the uterus, f tubes, ovaries and destroy mucosa
PID scarring often causes permanent damage, ectopic preg and other dangerous complications, severe or chronic ab or pelvic pain
infertility-PID can be directly responsible for infertility, 12-20% of women become sterile after 1 episode |
|
|
Term
|
Definition
aka DGI
conococcemia or arthitis-dermatosis syndrome
condition charac by hemorhaggic pustles, rash, recurrent fever, body aches, pain/and or arthritis in one or several joints
affects 1 to 3 % untreated GC px
bacteria cross mucosal barrier and enter bloodstream
results in bactermia and systemic dx
blood cultures are pos
endocariditis and men may develop (rare) |
|
|
Term
GC infectins in infants and children |
|
Definition
infants:aquire GC during delivery
1.opthamalic neonatrorum-gonococcal conjunctivitis is a major preventable cause of blindness in newborns, antibiotic eye drops given to prevent
2.DGI possible-may result in joint infections or a life threatening blood infection in the baby
Children: clinical infection of GC infection is dx for sexual assalt/abuse |
|
|
Term
|
Definition
laboratory charac
1.gram stain-used for presumptive ID of GC infections in urethral and cervicalexudates, must be confirmed, not recomended for pharyngeal or rectal specimans
2. culture-clinical specimans cultured on selective media (thayer-martin), culture blood/CSF if DGI suspected
3. presumptive dx of GC infections depends on, typical colony morphology, gram stain, postive biochem tests
additioanl tests must be performed but antibiotic therapy can start w/o |
|
|
Term
|
Definition
nucleic acid amplification tests (NAATs) detect pathogen specific DNA or RNA in a clincial speciman
developed in response to difficulties in maintaining approp culture conditions
do not require viable bacteria-are specific, sensitive, and reliable |
|
|
Term
|
Definition
antibiotic therapy is effective in elim the infection
inc prevalence of antibiotic resistant strains-an emerging public health threat
asymptomatic infections=no tx=inc risk for comp and transmission
antibiotic therapy will not repair permanent damage-ex like infertility issues |
|
|
Term
|
Definition
prevention of GC infections:
1.no effective vaccine currently avail to prevent gonorrhea
2.infection is not protective against reinfection
3. to avoid/dec risks of GC infection, practice abstinence/safe sex, seek prompt medical attention for abdominal urogential sx, inform all recent sex partneers if dx so they can seek tx
***asymptomatic males and females major problem |
|
|
Term
|
Definition
gram positive rod
more frequently seen in immunocompromised px, high freq of disseminated infections in pregnancy
seen in neonates, elderly, and imunocompromised
freq causes infections in CNS |
|
|
Term
microbiology listeria monocytogenes
*motility?
*how does this look on a gram stain? |
|
Definition
exhibits tumbiling motility (tumbles around in drop of saline) from flagella
can be mistaken for gram neg when discolorized from improper technique
requires thourough pasterization
can multiple at 4 deg C-ex in grocers fridge |
|
|
Term
epidemilology of listeria monocytogenes |
|
Definition
zoonois
assoc w/ milk and milk products in particular soft cheeses
any failure in pasteurization can lead to organisms that then mult at 4 deg C or survive in freeze
2000 cases/yr and around 400 deaths/year
happens freq in infants younger than 1 month, adults older than 60, pregn women, alterred cell mediated immunity
|
|
|
Term
|
Definition
ingestion of organisms
replicates intracellularly: like S typhi, tuberculosis, legionella penomphila
attaches to intestinal epithelial cell and macrophages
once in phagolysosomes secretes a hemolysin (listeriolysin) which allows escape from the phagosome and pelication in the cytoplasm
alter cell shape and actin extreded processes aloow for cell to cell spread
predilection for the placental and CNS
large outbreaks generally dairy products, recently cantelopes and caramel apples |
|
|
Term
immunity to listeria monocytogenes |
|
Definition
innate and cellular immunity
preg and neonate have lowwered immunity
lymphoma, transplant px on imminosuppressive, AIDS px, px on steroids, other cell mediated immune defects
px receiving TNF blocking agents
elderly |
|
|
Term
clinical syndromes listeria monocytogenes |
|
Definition
pregnancy and neonates-women infect placenta and fetus in utero-"vertical transmission"
meningitis and encephalitis, bacteremia-in AIDS px, elderly, transplant px |
|
|
Term
listeria monocytogenes tx |
|
Definition
ampicillin-penicillin base works and inhibits peptidoglycan
trimethorim sulfamethoxasole
--said we wont really have to know this slide |
|
|
Term
prevention of listeria monocytogenes |
|
Definition
thoroughly cook raw food from animal sources
wash raw veggies and fruit througholy before eating
keep uncooked meat sep from vegs or ready to eat food
avoid unpasteurized products from unpasteurized milk
wash hands, knives, and cutting boards after handling uncooked foods
comsume perishable and ready to eat foods asap |
|
|
Term
high risk px considerations w/ listera monocytogenes |
|
Definition
dont eat uncooked meat
pay extra attention to avoid dairy, soft cheeses, european food often not pasteurized, packaged meat, fishes |
|
|
Term
Corynebacterium diptheria |
|
Definition
other types corynebacterium part of normal flora
dipthera comes from greek word leather
gram pos bacillus-"chinese letter appearance"
grows on blood agar but use of tellurite agar improves ID and recovery
dx producing strains carry a beta phage encoding gene for toxic production (tox+) |
|
|
Term
epidemiology of C. diptheriae
-what is this bacteria's reservoir? |
|
Definition
previoulsy devastating dx w/ epidemics now controlled largely through use of vaccination
humans now only reservoir
spread by droplet or airborne spread
went from 200,000 cases/yr to about 5 |
|
|
Term
russian outbreak diptheria |
|
Definition
young children seem to be proteced mothers antigens
may be possible lack of follow up immunizations b/c this
The 2006 WHO summary
-8229 cases of dip worldwide
78% were from SE asia with 89% of those from india, greater than 30 cases from afghanistan, haiti, DR, indonesia, papua new guinea, phillipines, vitenam, nigeria |
|
|
Term
|
Definition
non invasive (localized infection=non invasive)
extoxin is produced:
-2 segments: B which binds to spec receptors on susceptible cells, and A, the active segment
**toxin ADP-ribosylates Elongation Factor (EF2) which is responsible for translocating tRNA resulting in cessation of protein synth(also seen w/ cholera and pertussis toxin)
targets heart (myocarditis), nerves (demylenation), and kidneys (tubular necrosis) VERY POTENT TOXIN** |
|
|
Term
diptheria clinical manifestations |
|
Definition
pharyngeal infection causes local necrosis and formation of pseudomembrane
this membrane is a leathery collection of cells attached to back of throat
this can detach and cause asipiration/suffication
bull neck assoc w/ massive lymphadenopathy |
|
|
Term
dyptheria as a toxin mediated disease |
|
Definition
related to extent of local dx and toxin production
cardiac-can be acute disease w/ CHF, myocarditis, conduction disturbances or a more chronic presentation
neuropathy both peripheral and cranial nerve neuropathy
renal |
|
|
Term
diptheria immunity and prevention |
|
Definition
no natural immunity
toxoid vaccine-formalin-inactived toxin used as vaccine
3 in the initial series, prior to high school, then every 10 years w/ Td
tx-penicillin and erythromicin should be active
may need antitoxin in severe disease |
|
|
Term
history bacillus anthracis |
|
Definition
biblical references to inflames papules
first disease attributed to a bacterium by Robert Koch in 1877 and fulfilled what became known as kochs postulates
pasteur developed attenuated strain and animal vaccine
inhalational anthrax among 19th cen british and german woolsorters and rag pickers
"accidental release of anthrax spores" 1979 from USSR facility in russia-70 cases
22 cases of human anthrax and 5 deaths-relatively lethal |
|
|
Term
microbilogy anthrax
-what does its shape look like?
motility?
capsule made of what? |
|
Definition
gram pos bacilli, non hemolytic growth on blood agar
***sporulates in prescence of O2
bacilli w/ prominent centeral or paracentral oval spores that do not cause swelling of the bacilli
poly-d-y-glutamic acid (PGA) capsule important in inhibition of phagocytosis of vegetative bacilli
catalase pos
non motile
"boxcar shape" oblong w/ central spore |
|
|
Term
|
Definition
PGA capsule encoded on the pXo2 plasmid
pXo1 plasmid encodes 3 components: protective antigen (PA), edema factor (EF), and lethal factor (LF)
Edema toxin-composed of PA combined with EF, produces local skin edema
lethal toxin-composed of same PA together with LF, was highly lethal for experimental animals
Combo of all 2 most lethal and produced many charac of actual anthrax infection |
|
|
Term
|
Definition
PA-so called b/c as an Ag it produces protective antibody, cleaved by cellular proteases to form heptamer
when the PA heptamer complexes w/ EF, it forms edema toxin, EF is a calmodulin-dependent, adenylate cyclase that inc intracellular cAMP concen and interefers w/ cell func
when the PA complexed w/ LF it forms lethal toxin, LF is a zince metalloprotease that cleaves and inactivers mult mitogen activated protein kinases (MAP kinase) and interfers w/ signal transduction
toxins are then taken into cytosol where they mediate cellular damage
2 component toxin-active site is actual toxin |
|
|
Term
|
Definition
local inoculation of spores
no purulence and painless
development of classic black eschar (scab); from dec blood supply
dev of significant local dx |
|
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Term
|
Definition
woolsorters dx-wool serpartaing put spores in air
rapid dx progression
pleural fluid and widened mediastinum-enlarging and hemorrhagic medistinal nodes
rapid progression to death
most common dx assoc w/ anthrax contaminated mail |
|
|
Term
other anthrax clinical syndromes |
|
Definition
GI- ingestion of contaminated food, unusal in humans
CNS anthrax-Meningitis, rapid progression, 1st case in the US post 911 cases |
|
|
Term
|
Definition
ciprofloxacin-quinolone
penicillin
tetracycline
-later 2 may be less effective in bioterror cases if resistance has been engineered in |
|
|
Term
|
Definition
stomanch, duodenum, jejunum has 1.0 x 10^2 bacteria
proximal ileum is 1.0 x 10^3
distal ileum is 1.0 x 10^8
colon is 1.0 x 10^11
human body has 6.0 x 10^13 cells
total bacteria is 1.0 x 10^14 bacteria
from 60x to 100x more bacteria than eukaryotic cells in our body |
|
|
Term
bacterial pathogens of GI tract |
|
Definition
Salmonella Spp
Shingella Spp
Yersine Spp
Vibrio Spp
Campylocbacter spp
helicobacter spp
escherichia coli
clostridium perfingens
bacillus spp |
|
|
Term
|
Definition
five prior "species' were reclassified as a single species: S.enterica with 5 major pathogenic serovars
Serovar is a group of closely related microorganisms distinguised by a charac sert of molecules that evoke and antibody response
S enterica Serovar tryphinmurium-mouse typhoid fever-can infect humans w/ mild GI
S enterica S coleraesuis-swine gastroenteritis
S enterica S enteriditis- gastroenteridis
S enterica S typhi-typhoid fever (human)-can be lethal
S enterica S paratyphi-Typhoid like (human) |
|
|
Term
|
Definition
gran neg
motile (Flagellated) bacillus
faculative anerobe
non lactose fermenter-utilizes other sugars
oxidase neg (reduction of DPD) (DPD=N,N dimethly-p-phenylenediamine)
sulfur reduction (alt energy production)
LPS: consists of O polysachh side chaine-lipopolysacch, in outer membrane, used for serotyping of strains |
|
|
Term
Culturing for Salmonella
-what is the special type of agar we use? how does it work? what happens with lactose fermentation? sulfur reduction? |
|
Definition
difficult to do a basic culture from a fecal matter test due to the large amount of bacteria in the GI
have to take advantage of phenotypes and growth requirements
salmonella is a non lactose fermenter and does sulfur reduction
use salmonella-shigar agar
selective medium for gram neg bacteria-bile salts inhibit Gm+
sugar utilization, colonies that ferment turn red due to an acid production that occurs during fermentation
sulfur reduction is from use of sodium disulfate in agar, if sulfur reduction occurs end product is black |
|
|
Term
importance of classifying different strains of salmonella |
|
Definition
see where infection started, if its the same kind in a group of people with outbreak, can indicate source of strain |
|
|
Term
|
Definition
flagallae-composed of arrays of flagellar proteins
very antigenically diverse in salmonella
antibodies against the flagellae of one strain of salmonella will not bind to flagellae expressed by a different strain of salmonella
have different side chains of LPS's in diff strains to create this diversity |
|
|
Term
|
Definition
recylcing of salmonella, with the exception of salmonella typhi, salmonellas are widely distributed in animals, providing a constant source of infection for man, exretion of large numbers of salmonellae from infected indiv and carries allow the organsims to be recylced |
|
|
Term
|
Definition
over 2,000,000 cases annually in US
recent outbreak in peanut butter |
|
|
Term
|
Definition
oral entry of infection
usually limited to intestine (non disseminiated-remains in GI)
invasive bacterium-enters into cytoplasm of gut cells
fever, nausea, cramps, diarehea
diarreha-electrolyte imbalance, dehydration
self limiting disease (2-4 days)
rarely can be fatal |
|
|
Term
salmonella invasion (enteridis) |
|
Definition
stim its own uptake into gut cells
induces rearrangement of the actin cytoskeleton of the host cell
plasma membrane "ruffling" observed prior to invasion by salmonella into the host cell |
|
|
Term
salmonella typhi
-what kind of host is this? |
|
Definition
obligate human pathogen
oral uptake; invades via intestines
dissemination from intestine via macrophages to lyphatics, blood, liver, kidneys, gall bladder, etc-sytemic bactermia
reinvasion of intestinal epithelium (hemorrhagic ulceration) this is like a crack in the intestianl epithelium
chroninc (asymptomatic) carriage in the gall bladder; shedding into the intestine "typhoid mary"
goes to GI, then systemic, then back to GI
|
|
|
Term
|
Definition
gut epithelium
peyer's patches-collections of m cells
m cells-set of specialized gut phagocytotic cells, uptake of proteins and other particles
salmonella spp exploit M cells for cellular invasion |
|
|
Term
salmonella enteridis v salmonella tryphi |
|
Definition
salmonella invase the intestinal epithelial cells to initiate infection
uptake replication in a phagosome survives in the phagosomal compartment
salmonella remain w/in membrane bound phagosome when in cell cytoplasm
S. enteridits has a deep tissue invasion
S typhi continues on to have systemic circulation |
|
|
Term
what genes are required for salmonella spp to cause disease |
|
Definition
mapping of virulence genes illustrated that the viruclence genes were clustered in the chromosome
pathogeniticy islands SPI-1 and SPI-2 |
|
|
Term
SPI-1
(pathogenecity island 1) |
|
Definition
know the genes in the section are important because mutations or deletions can reduce infective capacity causing avirulence
also found knocking out specific genes could cause complete loss of virulence because these genes had a special secretion system |
|
|
Term
|
Definition
injects proteins into cytoplasm of infected cell to manipulate cell functions (bacteria has to interact w/ cytoskeleton but this secretion system actually gets it inside)
comes from SPI-1 (pathogenesis island 1)
injects sip/ssp effector proteins into the cell
these proteins are actually injected like a hyperdermic needles
stimulates uptake of bacterium into the host cell
|
|
|
Term
pathogenesis island 2 (SPI-2) |
|
Definition
responsible for survival in host cell after path island one actually gets it inside
participates in avoidance of antimicrobial activities, modification of cellular trafficking, intracellular survival and replication
secretes SSE-salmonella secretion effector proteins |
|
|
Term
Shingella spp. and species |
|
Definition
causitive agent bacterial dystentary
all 4 species cause bacteria dysentary
shingella boydii-uncommonly isolated
shingella flexneri-developing countries
shingella sonnei-industrialized countries
shingella dysenteriae-most severe infections, can be lethal |
|
|
Term
shingella infections occurance
*what is sig about the number of bacteria needed to cause an infection?
*natural host? |
|
Definition
humans are only reservoir for shingella spp
obligate human pathogen
highly infectious (only 5-50 bacteria needed to elicit a shingella infection)
(salmonella need 100,000 to 1 million to cx infection)
about 24,000 causes in 1995 in US |
|
|
Term
|
Definition
gram negative, non motile bacillus (no flagellae)
faculative anaerobe (aerobic or anaerobic)
non lactose fermenter (utilizes other sugars)
oxidase neg
LPS-consits of O polysaccharide side chains-used for serotyping of strains |
|
|
Term
|
Definition
bile salts to inhibit Gm+ bacteria
lactorse, sucrose, salicin
bromothymol blue for sugar fermentors (acidic-yellow/fermenting)(alkaline-blue/green)
shingella produces raised, green, moist colonies |
|
|
Term
serological targets for differentiating shingella strains/speicies |
|
Definition
oligosaccharides of LPS are MUCH less diverse than in salmonella
only about 45 antigen serotypes
no flagellar antigens |
|
|
Term
|
Definition
abdominal cramps, fever, diareha which sheds bacteria
infections of submucosal cells of the lining of the intestine, does NOT commonly disseminate beyond the gut
inflammation, loss (sloughing) of the epithelial cells of the gut lining
ulcerative lesions form on lining of gut
stool contains copious amounts of mucous and blood-unlike salmonella infections
dehydration and elctrolyte imbalances can be LETHAL |
|
|
Term
shingella virulence plasmid |
|
Definition
pWR501
encodes genes for invastion
extrachromosomal invasive phenotype, 200 kbp
30,000 bp region of the plasmid=required for the invasive phenotypes
"entry region"-encodes invasion (Ipa) proteins and a type 3 secretion system
type 3 secretion system injects Ipa proteins into the cell |
|
|
Term
|
Definition
invades through M cells
invades epithelial cell in vacuole
type 3 secretion system injects Ipa into cell
lysis of vacuolar membrane (IpaB)
escape from phagosome and relase of the bacterium into the cytoplasm; rich intracellular "soup"
replication occurs in cytoplasm
shiga toxin interrupts ceullar protein synthesis
no flagellae-unique type of mobility controlled by IpaC |
|
|
Term
rocket motility of shigella |
|
Definition
induces actin polymerizatin in the host cell for rocket propulsion for cell to cell spread
hides from the immune system w/in the infected epithelial cells
physically moves cell to cell |
|
|
Term
serological targets salmonella |
|
Definition
more than 2400 O serotypes (Ab specific)
more than 119 H (Flagellar) serotypes |
|
|
Term
|
Definition
viral, parasitic, bacterial, fungal
about 20 million a year
about 1 million people a day contract an STI
stis often have no warning signs or sx
complications can progress before infection identified
true incidence vastly underestimated
large proportion infections asymptomatic |
|
|
Term
|
Definition
15-24 represent only 25% of sexually active pop but account for about 50% of all STI dx/yr
est about 12000 24 year olds contract an STI every day in US
female 4 times more likely to contract |
|
|
Term
|
Definition
chlamydiae are gram neg obligatge intraceullular bacteria-depend on host cell for survival and replication
chlamydiae consist of 3 speicies-all cause human disease
c. trachomatis-causes ocular and genital infections
c. pneumoniae causes outbreaks of respirtatory tract infections, spreads from person to person
c psittaci-transmitted from infected birds or animals to humans through RT, causes in flu like illness called psittacosis |
|
|
Term
what are the 4 important pts to remember about chlamydia? |
|
Definition
1.chalmydia (STI) and trachoma (eye dx) are caused by gram negative bacteria chlamydia trachomtis (chlamydia infection also refers to infection caused by any species belonging to genus chlamydia)
2.c trachmatis is naturally found living only inside human cells
3.one of the most common treatable STIs worldwide (>95 million cases/year)
4.single most important infectious agent assoc w/ blindness-approx 600 million worldwide suffer C. tachomatis eye infections and 20 mill are blinded as a result of the infection |
|
|
Term
chlam transmission and prevalence |
|
Definition
can be transmitted vaginal, oral, anal sex, childbirth
**Most common STI in US-1.4 mill cases in 2013, est 3 mill assitional ppl are infected in the US w/o knowing due to asymptomatic
known as silent epidemic b/c in 75% of cases in women it may not cause any sx-of those who have an asx infection that is not detected, 50% will develop PID
PID can cause scarring inside the reproductive organs which cause serious complications, including chronic pelvic pain, infertility, ectopic (tubual preg)
affects all ages, most common 15-29 |
|
|
Term
|
Definition
as many as 1 in 4 men have no sx
may produce sx similar to gonorehae which include burning during urination, discharge penis or rectum, testicular tenderness or pain, rectal pain |
|
|
Term
|
Definition
3 in 4 women experience no sx
burning during peeing, painful sex, vaginal discharge or bleeding after intercourse, rectal discharge or painl, abdominal or lower back pain, sx of pid, liver inflammation similar to hepatitis
|
|
|
Term
complications chlamydia infection |
|
Definition
untx'd infections can cause serious preoductive and other health probs w/ both short-term and long-term consequences
-PID (women) chlamydia causes quarter mill/half mill PID sx a year
sterility (men and women)
blindness (women and infants)
lymphogranuloma venerium-infection lymph nodes
reactive arthritis (reiter's syndrome)-triad of arthritis, conjunctivitis, and urethritis (inflammation urethra most common in men)
infants-maternal infect may result in spontaneous abortion, premature birth, conjucntiviis (possible blindness), and pneumonia, half of all infants born to mothers w/ chalmydia will be born with dx |
|
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Term
|
Definition
NAATS prefered dx tool-specimens obtrained vaginal swab in women, first catch urine in men
approp antibiotic tx for chlam is crucial (has to penetrate into cell)
early antibiotic tx extrememly successful and may prevent the development of long term permanent complication
untx'd infection may result in infertility
follow up eval should be done after 4 weeks to determine cured state |
|
|
Term
importance of dx and
-how does infection affect HIV affinity? |
|
Definition
can get mult stis from same encounter-pos for one means screened for others as well
other parters should be screened as well
all must be tx'd
no immunity following an infection
increases changes of HIV infection 5 fold
if preg can cause premature labor and delivery, in addition infact may develop chlam conjunctivis and pneumonia |
|
|
Term
|
Definition
safe sex-condoms
annual screening women sexually active 25 and younger, women over 25 with newer or mult sex partners
call dr if experiences sx
screening periodically
can't be contracted through toilets, daily activities, hot tobs, sharing utensils, clothing
previous infection not protective against reinfection |
|
|
Term
|
Definition
distinctive gram neg bacteria which are long, thin, motile, spiral cells
widespread in viscous enviros (aquatic sediments and mud, biofilms, mucosal surfaces) found in intestinal tracts and oral cavity of mammals
distinguised from other bacteria by location of flagella (aka axial filamanets) which run lenthwise b/w bacterial inner and outer membrane
when filaments rotate, move in cork screw fashion through enviro |
|
|
Term
|
Definition
dx causing members of phylum include
treponema palllidum-sphyillis
borrelia burgdoferi-lyme disease
borrelia recuurentis-relapsing fever
leptospira species-leptospirosis |
|
|
Term
|
Definition
sphyillus
bacteria spread through broken skin or mucous membranes, transmitted sexually and disseminates, can be passed in utero to cause still births, newborn death, defomities, seizures
can persist for decades in human host
challenging to study b/c can't be cultured or genetically manip in lab-must be propogated in rabbit testes to maintain strains for research investigations
several stages-sx depend on stages-many people do not have sx |
|
|
Term
|
Definition
can be generally tx'd w/ antibiotics, if left untx'd syphillus can damage heart, brain, eyes, and bones, in some cases this can be fatal
believved to have infected 12 million people worldwide w/ grater than 90% in developing world
rates cont to inc since turn of millenia
partially due to inc unsafes sex practices
currently widespread in US-affects sexually active adults ages 15-45 and esp gay dudes
can also be aquired with iv abuse |
|
|
Term
|
Definition
after being on verge of elim in 2000 in the US, syphillus cases have rebounded
75% of 1st deg and 2nd deg occured amound gay dudes
33%-50% of indiv become infected after sexual contact with syphillic partner |
|
|
Term
|
Definition
primary stage
painless small open sore called chancres form at infection site about 2-3 weeks after infection
heal and dissappear in 3-6 weeks, may go unoticed in rectum or cervix
enlarged lymph nodes may occur near area containing the chancre
bacteria continue to mult but there is little evidence of dx until 2nd stage |
|
|
Term
secondary (2nd stage) syphillis |
|
Definition
if untx'd will progress to 2nd stage
bacteria spread into bloodstream
occurs about 2-8 weeks (up to 6 months( after chancre forms)
most common sx is skin rash usually on palms and soles
lesions called mucous patches may be seen in mouth of gentials
moist, warty patches may develop on gentials or skin folds
additional sx like malaise, fever, general ill feeling, loss of appetite, muscle aches, joint pain, enlarged lymph nodes, hair loss may also occur
sx go away as bacteria becomes dormant again |
|
|
Term
|
Definition
final stage of syphillis-follows intial infection 3-15 years (up to 50 has been documented)
bacteria grow and spread to brain, CNS, heart, skin
pockets called gummas affect various tissues and are very destructive
sx depend on which organ system affects
"great imitator" because 1st and 2nd stages long forgotten
life threatening complications 3 deg syph rarely seen today b/c early detection and tx
late syph is premenatly disabling and may be fatal |
|
|
Term
some symptomatic probs teritiary syph include
|
|
Definition
cadiovascular syph-aneurysms or valve dx
neurosyph-CNS and neurologic disorders
gummas-destructive, infiltrative tumors of skin bones or liver |
|
|
Term
syphillis tx and prognosis |
|
Definition
can be completely cured if dx early and tx'd thouroughly
1st and 2nd deg can be tx'd w/ antibioitcs
follow up blood tests must be done at 3, 6, 12 and 24 months
avoid sex when chancre present, uses condoms until 2 follow up tests neg
partners tx'd
can't be contracted toilets, hot tubs, clothing, utensils
no protection previous infection |
|
|
Term
|
Definition
gran neg spirochete that causes lyme dx
unlike t palidum, can be cultured in lab, however bacterium is fastidious and requires complex growth medium-even under optimal conditions
invades blood tissues infected mammals and birds
natural reservoir is white footed mouse
ticks transfer spirochetes to deer, humans, and other warm blooded animals after a blood meal on infected animal |
|
|
Term
|
Definition
named after lyme CT from outbreak in 1975
cause of tick borne dx remained a mystery until 1981 when identified, also has been around for a long time
classified as a zoonois
most common tick borne infectious dx in N. America and N hemisphere
3 interrelated elements must be present for lyme to exist in an area-
1.B. burgdorfeni bacteria
2. ticks that can transmit them
3. mammals to provide food
lyme disease occurs in stages |
|
|
Term
transmission lyme disease |
|
Definition
life cycle of B burgdoferi is complex requiring ticks, rodents and deer at various points; micre primary reservoir, ticks then transmist bacteria to other humans
most infections caused are by nymphomal stage ticks-small nymphs produce secretions that prevent the host from feeling any itch or pain from bite, as a result, the ticks may feed for long periods of time unprotected
transmission quite rare, takes more than 24 hours for attachment for bacteria to transfer, thus tick checks useful |
|
|
Term
|
Definition
can spread throughout body during course of dx, found in skin, heart, joint, PNS, CNS
as a result can affect mult body systems and produce a range of sx-many sx result
incubation period 1-2 days but can be hours or years
infection can be elim by antibiotics if illness dx early
delayed or inadequate tx can lead to more serious sx, which can be diabling and difficult to tx and persist for decades |
|
|
Term
|
Definition
early localized infection
circular expanding rash called eythema migrams (EM) that has bullseye appearance
also flu like sx such as headache, muscle soreness, fever, and malaise
can progress to later stages in px who do not develop a rash |
|
|
Term
|
Definition
early disseminated infection
can be dayts to week after local infection onset
may disseminate from tick bite
EM may develop at additional sites
other sx heart palpitation, dizzieness, and/or migrating pains in muscles, joints, tendons
various neuro sx included facial palsy, muscle/joint pain, shooting pains, abnormal skin sensations, sleep disturbances, mood changes/alterend mental status |
|
|
Term
|
Definition
late persistent infection
after several months, px may go on to develop severe, chronic, and disabling sx that affect many parts of the body including brain, nerves , eyes, joints, and heart
lyme arthritis, usually in knees or larger joint, in 10-15% may lead to erosion of cartilage or bone
chronic neuro sx in 5% px involving shooting pains, numbness, tingling in hands or feet, profound fatigue, difficulites concen or short term memory probs, neuropsych affects |
|
|
Term
|
Definition
lyme disease dx clinically based on sx, onjuective physical findings, hx or possible exposure to ticks, serologically blood tests (Not effective til later stages)
EM rash considered sufficient for dx even when blood tests neg, however not all px will get a charac rash or recall tick bite
bottelia are slow growing and can delay dx
dx late stage lyme complicatioed by multifacitaed appearance and non specific sx, prompting some med professionals to call it great imitator-looks like other diesease like lupus, fibromyalgia |
|
|
Term
|
Definition
several forms lab testing now avail
most used serological testing which measures specific levels of antibodies in blood, however, these tests often neg in early infec, and may not produce a sig quantity of antibodies til later stages, have high rates of false positives
PCR (polymerase chain reaction) also detects however not widely performed bc it often shows false negative results and CSF specimans, several labs perform PCR on ticks |
|
|
Term
|
Definition
avoid tick invested areas from may to aug
perform tick checks/proper removal w/in 24 hours
single antibiotic dose given w/in 72 hours after high risk exposure can prevent development of lyme
hx of previous lyme does not offer immunity
exposure can be reduced w/ simple landscaping like a gravel or wood buffer in between woods and recreation areas
community can dec lyme by dec hosts (rats) |
|
|
Term
|
Definition
antibiotics primary tx
since dx lyme, is based on clinc findings, it is often approp to tx px w/ early dx soley on basis od sx and a known exposure, newly dx cases are tx'd w/ antibiotics for 2-4 weeks and most px make an uneventful and complete recovery
|
|
|
Term
|
Definition
early cases-prompt tx curative
some px w/ lume have fatigue, joint pain, and neuor sx exisiting for years despite tx
also called chronic lyme or post tx lyme dx ptld-depends on damage done initially
severity and tx may be complicated due to late dx, px w/ late stage lyme may have been shown to experience a level of physical disability equiv to that seen in CHF
in rare cases lyme is fatal |
|
|
Term
|
Definition
known as fok lun in samhita-1600's
very old
john snow-first instance of defining source of infection using epidemilogy
bacteria identified by robert koch in 1882
|
|
|
Term
|
Definition
severe diarrehal sx
"rice water stool" (mucus)
5-20 L water loss/day |
|
|
Term
appearance vibrio cholera |
|
Definition
single flagellum
looks like a computer mouse |
|
|
Term
|
Definition
endemic in asia w/ 8 million cases annually 124,000 deaths (bangladesh, southern india, vietnam) etc
sever pandemics since 1817
entry into westerm hemishere
peru, alabame, chile 1991-1994
haiti-2010 |
|
|
Term
|
Definition
gram neg, motile (flagella) bacillus
comma shaped bacterium
pilus (attachement) to epithelium
faculative anaerobe
free living and in gut
glucose and sucrose utilization (ferments)
oxidase-positive reaction in assay
capsule (polysaccharrides)-serotyping
gram neg-LPS antigenic variants used for serotyping |
|
|
Term
serological differntiating vibrio cholerae strains |
|
Definition
capsular polysaccharides used to serologically differntiate virbio cholerae strains, most prevalent strains O1 and O139
prior to 1993, O139
6th, 7th pandemics in haiti caused o1 serotype
more than 138 serotypes |
|
|
Term
|
Definition
pretty much only thing V cholerae will grow on
bile salts (no gram +) ph 8.6 (high)
thiosulfate (sulfur)
citrate
sucrose
bromythmol blue
vibrio cholera-yellow (low pH) (sucrose fermentor) |
|
|
Term
|
Definition
20 species of vibrio have been identified
12 of these are responsible for human dx
v cholerae-potentially lethal intestinal infection
v vulnificus-fisherman; highly letahl systemic infection |
|
|
Term
virulence factors v cholerae O1 and O139 |
|
Definition
cholera toxin-hypersecretion electrolytes and water
coregulated pilus(coregulated b/c only expressed when cholera is expressed)-adhearance to mucousal cells
accesorry colinzation-adhesion factor
hemagglutination protease (mucinase)-induces intestinal inflammation and degradation of tight junctions
siderophores-iron sequestration
neuramidase-inc toxin receptors |
|
|
Term
|
Definition
oral route
flagella; motility is required, swim through the mucus lining to the gut epithelial cells
toxin-corregulated pilus, attachment of bacterium to gut cells
HA protease ('detachase')-v cholerae is shed from the gut in diarrehal fluids-can cleave itself and flow out of guy
dispersal to other persons, contraminated food, water etc
-60% mortality rate
non invasive-attachement of v cholerae to gut epithelial requires interaction b/w bacterium's pilus and the microvilli ("brush border") on the gut cells surface |
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Term
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Definition
heat labile protein (enterotoxin) secreted by V cholerae into the lumen of the guy
binds to ganlisodie GM1 receptor located on surface of gut epithelial cells
5B monomores, and 2 alpha monomers, actual alpha unit causing interaction
elevates level of intracellular cAMP, stim release of electrolytes (K+,Na+) from the cell-pores of epithelium permanently open
cell water follows ion gradient
severe diarehal sx (rice water mucousy stool)
death by electrolytic shock |
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Term
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Definition
virbio like bacterium
promiscuous host range-major cause of diarrheal dx in animals, cattle, sheep, rodents, poultry, dogs, cats, birds
recently these bacteria have been implicated in human dx
gram neg encapsulated helical bacillis (curved or spiral rod)
motile (flagellated) (2!)
doesnt ferment sugar
microaerophillic (requires CO2 for growth)
too small to be easily observable by brightfield microscopy (reveleaved by scanning electron) |
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Term
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Definition
C. jenjuni-acute gastroenteritis
C. fetus systemic infection/bactermia, meningitis, and septic fetal abortions,
C. coli-procitis, gastroenteritis, septic fetal abortions |
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Term
virulence features campylobacter spp |
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Definition
factors have not been well defined for motility, attachment, invasion |
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Term
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Definition
mucosal surface of intestine is ulcerated, edematous, bloody, inflammes (more acute than v cholerae)
monocytes are attracted to area
roles for cytopathic toxins, but enterotoxins and endotoxic activity have not been well defined |
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Term
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Definition
autoimmune dx thought to be elicited by antigentic cross reactivity b/w the capsule polysaccharides and sugar containing lipids on surface of neuronal cells
assoc w/ campylobacter |
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Term
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Definition
gastroenteridis
UTIs
neonatal meningitis
peritonitis
mastitis
septicemia
pneumonia
hemolytyic uremic syndrom |
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Term
e coli as part of gut flora |
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Definition
symbiotic relationship b/w ourselves and our gut flora
e coli is a normal consitiuent of our gut flora
less than 0.1% of culturable microflora in the gut is non patho eschericia coli |
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Term
Jack in the box e coli outbreak |
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Definition
73 different locations were linked to food poisoning
hemolytic uremic syndrom (shiga toxin)
isolated to e coli
sickened over 700 people
171 hospitalizations, 4 deaths |
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Term
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Definition
gran neg bacillus
normal member of gut flora
faculative anaerobe
ferments sugars (glucose, lactose)
flagellated or non flagellated
often express pili and/or fimbriae
genetically diverse
-20% of genome common to all strains |
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Term
Serological seperating E Coli |
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Definition
LPS, flagellar, and capsular polysacchariddes (if cap polysachs produced) are used to serologically differentiate strains of E Coli
K antigens in capsule
O antigens in LPS
H antigens in flagellum |
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Term
Seven phenotypes of E. coli
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Definition
nicknamed swiss army knife of pathogens
EPEC ETEC EHEC EIEC EAEC UPEC NMEC |
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Term
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Definition
(enteropathogenic e coli)
site of action-SI
dx-infant diareha, watery diareha, vomiting, non bloody stools
pathogenesis-plasmid mediated histopathology, disruption of microvillus struc |
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Term
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Definition
enterotoxigenic e coli
site of action- small intestine
dx-travelers diareha, watery diareha, cramps, nausea, low grade fever
pathogenesis-plasmid mediated heat stable and/or heat labelle enterotoxins, hypersecretion of fluids and electrolytes |
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Term
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Definition
enterhemmorhagic e coli
site of action-large intestine
dx-inital watery diareha, followed by grossly bloody diareaha, cramps, little to no fever, may progress to hemolytic uremic syndrome (O157;H7) pathogen-mediated by shiga toxins (stx 1, stx2) disrupts protein synth, A/E lesions
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Term
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Definition
enteroinvasive e coli
site of action-large intestine
dx-fever, cramps, watery diareaha, may progress to dysentery w/ scant bloody stools
pathogen-plasmid mediated invasion and destruction of epithelial cells lining the guy |
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Term
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Definition
enteroaggregative e coli
site of action- small intestine
dx-travelers diareha, persistant watery diareha w/ vomiting, dehydration, and low grade fever
pathogen-plasmid mediated aggregative adhearance of rods (stacked bricks) shortened microvilli, mononuclear infiltration, hemorhage |
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Term
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Definition
extraintestinal e coli
site of action-uritogential tract
dx-inflammation of UT,
pathogen-produces specific adhesions P pIII, AAF/I, AAF/III, Dr |
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Term
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Definition
neonatal e coli
site of action-brain
dx-meningitic; majority of CNS infections in infants less than a month of age; often present in mothers and neonates GI tract
pathogen-most strains produce the K1 capsular antigen |
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Term
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Definition
effacement (destruction)of microvilli
type III secretion system; effector proteins alter cytoskelton
pedicle formation, stimulates apoptosis
Tir effect-receptor for bacterium |
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Term
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Definition
increases intraceullar cGMP (STa), cAMP (LT)
heat stable toxin (STa)
Heat labile enterotoxin (LT)
labile toxin (LT) similar to cholera toxin
opens ion channels in the intoxicated cell
loss of ions; intracellular water follows osmotic gradient-diareha
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Term
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Definition
shiga toxins: disrupt synthesis of proteins in infected cell; inactivates ribosomes
60MDa virulence plasmid
**Death w/in 3-5% px with hemolytic uremic syndrom
30% of HUS px can have lifelong CNS and renal impairment |
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Term
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Definition
similar to shigella
invades into cytoplasm of cell
"rocket" motility, polymerization of action
likely sim phenotypes b/c it invades wall
Inv plasmid: encodes for invasion functions similar to the Inv plasmids of Shigella spp
invades much like shigella |
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Term
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Definition
whole groups of pilli can bind to each other
plasmid-mediated adhearance
stacked brick colonization-binds to itself
bundle forming pilli
shortened microvilli evident
intestinal hemorrhage-ulcerations and breaks in guy lining |
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Term
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Definition
dont really care for guy
most strains of e coli can produce UTIs
Type I fimbriae-adheres to bacteria to UT epithelium |
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