Term
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Definition
single flagellum at one pole of the cell
ex: Vibrio - all Vibrio have one polar flagella |
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Term
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Definition
In prokaryotes: rotates (propellar) and is powered by a proton motive force
found in gram postive and gram negative bacteria
*chemotaxis
filament extending from bacteriam is composed of the flagellin protien, which is a major antigentic target (high copy number) and is also called and H-Ag bc its a heat labile Ag
*recognized by TLR5
Structure: filament attaches to a hook, hook attaches to the basal body anchoring it to the cell membrane
In Euk: whip-like and is powered by ATP hydrolysis |
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Term
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Definition
one pole with several flagella |
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Term
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Definition
flagella all over the cell
ex: Salmonella and Escherichia |
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Term
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Definition
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Term
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Definition
characteristic of spirochetes
wound around the cell and are not exposed to the external env.
forms an axial filament, with the flagella in the periplasm
rotation of the flagella causes the bacterium to move like a corkscrew (ex: syphillis)
very efficient for moving thru tissues |
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Term
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Definition
cillia-like structures ONLY found in prok
(cillia are found in Euk)
Fimbriae: proteinaceus projections (PILIN) used for adherence
pilli are also proteinaceus projections but are used for the transfere of genetic material(aka SEX)
found in both gram + and -
two major fxns:
- adherence to other cells, tissues or surfaces - colonization and formation of biofilms (organized systems of bacteria)
- motility, twitiching and gliding - the extension and retraction of the pili
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Term
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Definition
Unique to bacteria (aka not in Euk, only in Prok)
The unique structure of the cell wall of bacteria makes is a target for antibiotic (penicillin)
Recognized by TLR
confers shape and protection from osmotic lysis
very porous - does not restrict diffusion of mols/prots
**some bacteria lack pep cell walls: Mycoplasma an Chlamydia
Composed of:
- Glycan: N-acetylymuramic acid and Nacetylglucosamine - linked disaccharide chains that repeat many times
- Peptido:pentapeptide-amino acids
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Term
Structure of Peptidoglycan (Gram positive v. Gram Negative) |
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Definition
Glycan (Disaccharide: N-acetylyamuramic acid (NAM) and N-acetylglucosamine(NAG)) linked to a pentapeptide and tetrapeptides (composed of amino acids) to form a cross linked mesh-like network
- In Gram (- ) 20% tetrapeptide cross link
- In Gram + 80% crosslinkage
*in some gram + there may be an additional pentaglycine intrapeptide bridge attached to the lysine in the third position
Gram + and Gram (-) are very simillar except for the third position
- Gram + have a L-lysine that may contain the interpeptide pentaglycine bridge
- there are 8 distinct forms of peptidoglycan found in gram +bacteria but they are NOT significant in terms of antimicrobial therapy
- Gram (-) have DAP *which is only found in prok
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Term
Peptidoglycan synthesis and crosslinkage |
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Definition
Synthesis:constantly occuring, inhibition of synth or crosslinking leads to cell death
- Single disaccharides (NAM-NAG) linked to a pentapeptide are synthesized in the cytoplasm and linked to a membrane bound bactoprenol carrier **this step is targeted by Bacitracin
- Translocated accross cytoplasmic membrane
- once outside the membrane, disaccharide chain is linked to a growing a glycan chain and crosslinking to other modules is completed
Crosslinking: confers rigidity to the cell wall
- catalyzed by transpeptidase activity of penicillin-binding protiens (PBPs) *** targeted by beta-lactams
- In gram (-) always occurs b/w DAP and fourth D-ala on the adjacent pentapeptide strand
- Gram + mainly occurs b/w terminal glycine of interpeptide bridge and 4th D-ala of adjacent pentapeptide
- Results in the release of the 5th amino acid (D-ala)
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Term
Do bacteria have cholesterol in their membranes? |
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Definition
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Term
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Definition
sphere
streptococcus and staphylococcus
BUT wait -- bacterial arrangment can be more helpful than shape ...
strep are in long chain cocci
staph are grape like clusters
(I would remember this) |
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Term
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Definition
elongated sphere
francisella |
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Term
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Definition
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Term
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Definition
Comma shaped
V. cholera
all share a common characteristic?
Monotrichous |
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Term
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Definition
rigid corkscrew
helicobacter pylori |
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Term
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Definition
flexible, corkscrew
treponema pallidium
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Term
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Definition
do not have a specific shape |
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Term
Gram Negative Bacterial Anatomy - Cell Layers |
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Definition
- Can contain a capsule - does not mean it always will - regulated by growth phase and env.
- Outer Membrane: (gram + do NOT have this!) contains LPS in outer leaflet and protiens that allow it to be a permeable barrier, and act as adhesions , enzymes and transporters *contains porins
- Peptidoglycan layer - thin, 1-2 layers, and not highly cross linked
- *periplasmic space -- its contains to the peptidoglycan layer and many enzymes involved in cell wall biosynth.
- cytoplasmic membrane: similar in both gram (-) and gram +
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Term
Gram Positive - cell layers |
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Definition
- Can contain a capsule - does not mean it always will
- Can have a surface protien layer (Fibrillar layer)***Gram (-) do NOT have this layer
- Peptidoglycan layer - highly crosslinked, 40 layers think
- cytoplasmic membrane
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Term
|
Definition
Extracellular, carb rich coating on some bacteria
made in the cell
Contains poly - saccharide/peptides and maybe lipids
two types:
- Capsule:repeating carb units, prevents cell from drying out, or can act as an alternate energy source; acts as a virulence factor by hiding the Ag component of bacterium from host, antiphagocytic---> target for vaccines **hard to stain due to carbs - usually stained with negative stain (india ink) capsule appears as a halo
- Slime Layer: (exopolysaccharide) loosely attached to cell surface, contributes to disease, ex: gooey alginate in lungs of CF patients from pseudomonas aeriginosa
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Term
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Definition
invaginations of plasma membranes, form vessicles in gram (-) and gram +
significance is not known |
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Term
|
Definition
(cell wall, cell membrane and outer membrane if present)
And again... 40 layers of peptidoglycan
Contains teichoic acid and Lipoteichoic acid:
- Teichoic acid is NOT found in gram (-)
- polymers of ribitol and glycerol phosphates
- highly Ag!!
- Teichoic acids are covalently linked to peptidoglycan
- lipoteichoic acids are anchored by a lipid tail to the cytoplasmic membrane
- aid in identification
also contain protiens and carbs
may or may not have fibrillar layer or capsule
can form spores (gram (-) can NOT form spores)
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Term
Penicillin Binding Protien (PBPs) |
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Definition
secreted protiens that are anchored to the outer surface of the cytoplasmic membrane (in both gram + and gram-)
divided in to two categories:
High molecular weight: ESSENTIAL for growth, encode tanspeptidaes(*crosslinking) and transglycosylase activites
**Beta lactams inhibit transpeptidases and carboxypeptidase activites
Low moleculare weight PBPs: not essential for growth, encode only carboxypeptidase |
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Term
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Definition
glycosidase, hydrolyses the bond btw NAM and NAG in the peptidoglycan layer
important for antibacterial defense
particularly against gram +, less important for gram (-) because they have the outer membrane which resist lysozyme activity
present in tears, saliva, and in the lysomes of phagocytic cells |
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Term
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Definition
Main fxn: permeability barrier - protect the cell from antibiotics, lysozymes, toxins. Diffusion limit is 600 Da
Houses protien transporters:
Porins - diffusion channels, that are essential open to allow passive diffusion of small molecules, can also fxn as adhesion mol. or in antibiotic resistance
Or many other protiens- adhesins, flagella/pilli, phage recognition, autoagregation |
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Term
|
Definition
outer membrane
responsible for the permeabiltiy barrier properties, and is ESSENTIAL for viability
Composed of :
O-Ag: composed of almost repeating units of oligosaccaharides, highly variable, not essential, can express a variation of Ag in many bacteria, O-ag positive bacteria have a smooth looking colony morphology
Core polysacchride: ESSENTIAL, 7 conserved carbs, also have some unique carbs (KDO and heptose)
Lipid A: ESSENTIAL,negative charge to LPS and the outer membrane
responsible for barrier properties,referred to as endotoxin, recognized by TLR4
(more details on another card)
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Term
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Definition
Lipid A: ESSENTIAL, Gram (-)
- acylated glucosamine disaccharide
- often phosphorylated imparting the negative charge to LPS and the outer membrane
- adaptive responses by some organisms that can cap the phosphorylation/enzymatically remove it --reduction in (-) charge and affects interaction with innate immune system (less negative =RESISTANCE)
- responsible for barrier properties
- referred to as endotoxin
- recognized by TLR4
- core protien binds O-Ag to Lipid A
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Term
LPS and the Outer Membrane |
|
Definition
Inside of Outer membrane: phospholipids
outerleaflet: LPS w/ negative charge - reduction of this negative charge leads to resistance to antimicrobial peptides and may affect TLR recognition (TLR4) and stimulation of PAMPs
LPS is stabilized in outer membrane by salt bridges formed by Mg 2+ bound to phosphates on adjecent LPS molecules
these salt bridges stabilize the outer membrane
inflammatory mediatory:
endotoxic shock - IL1 (fever), macrophages, PMN activation and oxidative burst, vascular permeabilty(hypotension), clotting activation, complement and tissue necrosis |
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|
Term
Type I: ATP binding cassette (ABC) transporter |
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Definition
ubiquitous, found in prok and Euks
transports drugs, carbs, peptides and protiens |
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|
Term
Type II: General Secretory Pathway(GSP) |
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Definition
Bacteria, chaperones and signal peptides |
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|
Term
Type III:contact dependent secretion systems |
|
Definition
not present in all bacteria-- pathogenic strains
important for pathogenesis - directly inject effector protiens into the host cells cytoplasm |
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|
Term
Type IV: associated with conjugation |
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Definition
evolved from pili, but may also secrete some exotoxin (helicobacter, pertussis toxin) |
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Term
|
Definition
related to porins
export protiens to the cell suface where they are released by the proteolytic cleavage into the extracellular space |
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Term
|
Definition
identified recently - secretion of some enzymes nad protien toxins |
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Term
How does protien export for gram + and gram (-) bacteria differ? |
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Definition
Gram (-) exportation must travel through 2 cell membranes -- cytoplasmic membrane and the outer membrane, and usually resides for a time in the periplasmic space for further processing before being secreted out into the env. |
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Term
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Definition
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Term
|
Definition
- extension of the cell wall
- replication of the genome
- segregation of chromosomes by membrane
- septum formation
- results in exponential growth : cell number = 2nwhere N is the number of divisions
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Term
|
Definition
is the change in the number of cells per unit of time |
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Term
|
Definition
Also called doubling time
time required for one cell to grow and divide into two cells
can range from mins to mo
depends on conditions - pH, temp, salt content, nutrient |
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Term
|
Definition
adaptation to a new enviroment
Can last an hr or days
cells may need to synth new enzymes to utilize nutrients in medium or adapt to pH, osmo, or temp |
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Term
|
Definition
max growth rate- max DNA and protien synth
growth rate is CONSTANT!
***Time when bacteria are most susceptible to drugs
preferred time for staining |
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Term
|
Definition
growth=death in culture pop
nutrient dep or accumulation of toxic waste
cells become metabolically inactive
induction of sporulation(*only in gram +)
***elevated resistance to antibiotics
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Term
|
Definition
greater rate of death than growth |
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Term
|
Definition
complex aggregation of miccrogranisms encased in a protective and adhesive carb matrix
characterized by surface attachements, sturtural heterogeneity, genetic diversity, and complex community interactions
most bacteria grow in biofilms-Dental plaques, formations on catheters, CF, contact lens, ear infections
Source of recurrent infections: biofilm associated bacteria are resistant to antibiotics, and are protected from the immune system - antiphagocytic |
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Term
|
Definition
Toxic byproduct produced during oxygen-mediated metabolism
broken down by catalase
oxygen tolerant organism have the enzymes to breakdown this product
aerobes contain both superoxide dismuates and catalase so that they can break down this toxic by product
obligate anaerobes cannot |
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Term
|
Definition
toxic by product of O-mediated metabolism
oxygen tolerant bacteria contain superoxide dismutase and are able to "detox" |
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Term
|
Definition
use O for respiration
obligates: require O
microaerophilles: require O level at 2-10% |
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Term
|
Definition
do not require O
obligate: cannot tolerate O -- they do not contain enzymes to detoxify superoxide or hyrdogen peroxide (superoxide dismutase , and catalase )
Aerotolerant - do not use aerobic metabolism but have enzymes that detox
facultative anaerobes : can undergo aerobic respiration or fermentation in the absense of O
* some lack catalase (to break down hyrdogen peroxide but all have superoxide dismutase) |
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Term
|
Definition
Too low: affect membrane fluidity and enzyme kinetics -->reduced growth rate
too high: protien denaturation, thermal lysis, and membrane collapse -->reduced growth rte (or death)
optimal temp: rxt occur at max rates = max growth rate
- Psychrophile - not a human health concern
- mesophiles - most human pathogens
- thermophiles - not human health concern
- hyperthermophiles - ""
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Term
|
Definition
normal acidity of certian region sof the body inhibit microbial growth -- but if this is altered ...
EX: vaginal secretions: remain at low pH due to residential flora, restricts growth of pathogenic microbes - but when altered (like antibiotics killing normal flora) the pathogenic microbes can move in = yeast infection |
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Term
|
Definition
an organism capable of synthesizing all of its own metabolic needs
(ecoli, salmonella, pseudomonas) |
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Term
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Definition
lost the ability to synthesize certain substances required for growth - results from mutational changes
Ex: Chlamydia, lactobacillia, haemophilus, Neisseriae, Francisella |
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Term
|
Definition
Iron is essential for growth
host defense: host have limited availabilty of iron by use of iron binding protiens (lactoferrin and transferrin) so not a lot of iron in cirrculation for bacteria
Pathogen response: iron stealing - specific transporter for lactoferrin and transferrin, along with the production of siderophores (iron binding compounds); cytotoxins to release intracellular stores of iron |
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Term
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Definition
taxonomic category, below family and above species - consisting of a group of species exhibiting similar characteristics |
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Term
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Definition
display similar characterisitics |
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Term
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Definition
arises from geographic separation of species |
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Term
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Definition
subset of species that differ by some minor but identifiable difference
can be defined by serotype(serological means)
can be defined by biotype(biochemical, drug resistance, agglutination of blood cells ect) |
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Term
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Definition
pure culture of organism, isolated from a heterogenous population of microorganism s |
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Term
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Definition
stains cells of genera Myobacterium and Nocardia (TB and Leprosy)
these bacteria have waxy lipids in cell walls - no water base dyes can get thru
method:
- fix bacteria on slide
- add carblofuchsin and hear - drive dye into slide
- wash with HCl - dye is washed away in nonacid fast cells
- counter stain with methylene blue
- Acid fast = red, non acid fast = blue
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Term
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Definition
derived from enviroment
finite time, removed with cleaning
can be pathogenic or non pathogenic |
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Term
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Definition
population of org regularly found at site (skin, mouth, GI **internal tissues should be free of microbes)
relatively stable
reestablishes itself following a disturbance
also called normal flora
mostly bacteria(1013) by some fungi and protozoa |
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Term
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Definition
GI tract: most populated region, primarily anerobic and faculatitive anerobic (esp colon)
many opportunistic pathogens - Salmonella, Pseudomonas, staph aureus, enterococus
Skin: also has some (staph epidermidis)
Internal:NONE!
bacteria occupy multiple niches (like staph) or just one nicne
there are multiple factors that can influence diveristy of flora at a site: Age and sex, Diet, sanitation |
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Term
Advantage of resident flora |
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Definition
antagonize bacterial growth:fatty acids, peroxides, bateriocins kill or inhibit nonindigenous species
synthesize and excrete Vitamins: vitamin K, vitamin B12
stimulate develpoment of certain tissues:Caecum and lymph, and immune system
prevent colonization thru competition of attachment and nutrients |
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Term
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Definition
Normal bacteria infect new sites- where they become pathogenic
While Ecoli is normal in GI it can be pathogenic in other sites - like lung or UT
Oral surgery can result in the introduction of strep to the blood stream --> abscesses in the alveolar bone, lung brain - can colonize heart valve
intraabdominal abscesses:anaerobes from GI can colonize
Oppprotunistic pathogens are present in our normal flora when immunocomprmised - surgery, trauma, antibiotics |
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Term
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Definition
result from a stay in the hosptial
2 million patients per year -90,000 deaths/yr
70% are antibiotic resistant : high prevalence, compromised host (25% are in ICU-immunocomp), efficient mechanism of transmission
***Hand washing is the single most important method to limit cross contamination |
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Term
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Definition
physical or chemical agents to inhibit or destroy microorganisms on inanimate objects
does not! guarantee all organisms are eliminated but does reduce the number of potential pathogens
Ex: alcohols, phenols, aldehydes, surfactants |
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Term
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Definition
use of chemical or physical agents called antiseptics to inhibts or destroy microorgansims on skin or other tissue
does not guarantee all organisms are eliminated - reduces the number of pathogens
ex: iodine, alcohol |
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Term
|
Definition
indicates inhibition not complete destruction
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Term
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Definition
indicates destruction or inactivation; germacides |
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Term
|
Definition
- Temp, pH affect death rates: warmer temp, more acidic -->kill more pathogen
- Compostition/ quantity of infectious material:fat, feces, vomit, bld, and secretions of biofilm interfere with effectivness of heat, chemicals, and some forms of radiation
- Contact time: longer the better
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Term
|
Definition
used to disinfect (ie surface not skin), sanitize, sterilize and pasteurize
Method: denatures protiens and detroys cell membrane
**more effective than dry heat - h2o is a better conductor of heat than air
EX: boiling, autoclaving, pasteurization |
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Term
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Definition
dairy products and fruit
not sterilization
kills pathogens but heat resistant microbes still live |
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Term
|
Definition
kills vegatative cells of bacteria, fungi, protazoans, and most viruses within 10 min at sea level
**boiling time is important (more time is needed at highter elevations)
not compelete sterilization -- endospores, protozoan cyst and some viruses can live on! |
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Term
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Definition
achieving true sterilization rq heat greater than 100 C
pressure is key to achieving such a temp
so basically you need - temp - 121C and 15 psi for 15 mins for true sterilization
*extra time for solid substancce and large vol. |
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Term
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Definition
material that cannot be sterilized with or are damaged by moist heat (powders, oil, metal)
method: denatures protiens and oxidizes metabolic and structural chemicals
requires higher temps and longer time than moist heat (171C for 1 hr or 160C for 2 hrs)
Incineration is a very effective form of sterilization -- think inoculating loop |
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Term
Refridgeration / freezing |
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Definition
halts growth (but NOT for yersinia or Listeria)
slow freezing works better - ice/water crystals puncture membranes |
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Term
|
Definition
exclude particles based on size - only if cant tolerate other methods of destruction (ex:protien solutions, drugs, antibiotics, serum )
fitlers are made of polymers with holes formed by a laser (0.2 micron hole) |
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Term
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Definition
High Efficiency particulate air filter
filters microbes out of air and gas
OR and ICU |
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Term
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Definition
shorter wavelenth (less than 1nm) so it has more energy, penetration and microbial control
creates ions by ejecting electrons from atoms
Electron beam results: rapid cell death but poor tissue penetration; used for sterilization of plastic, medical and dentals supplies
Gamma ray results: slow death but good tissue penetration, sterilizes food |
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Term
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Definition
wavelength is greater than 1 nm
excites e-, making new covalent bonds
affects protien and nucleic acid structure
UV radiation: Thymidine dimmers, poor tissue penetration, disinfects air, transparent fluids, and surfaces
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Term
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Definition
methods: denatures protiens and disrupts cell membranes
uses: organic matter (bld, vommit, feces) remains active for a long time
used in health care settings, labs and homes(lysol)
bad odor and can cause rashes and irritation
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Term
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Definition
Bacteriocidal, fungicidal, virucidal, against enveloped viruses ***but not fungal spores or endospores
method: denatures protiens and disrupts cell membrane, dessicates
evaporates rapidly - this can be good (no residue to be spread) but short exposure time
uses: tinctures, swabbing skin (antisepsis) with 70% and can be a disinfectant |
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Term
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Definition
Iodine, Bromide, Flourine, Chloride
effective against: vegatative bacterial and fungal cells, fungal spores, some bacterial spores, protazoan cysts and viruses
method: damages enzymes via oxidation or by denaturing
ex: iodine tablets, tincture, Cl treatment of h2o |
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Term
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Definition
peroxide, ozone, and peracetic acid
method: kill be oxidation of the microbial enzyme
ex: hydrogen peroxide - disinfectant and sterilize surface objects(can be neutralized by catalase)
Ozone - treatment of h20
peracetic acid - sporocid, sterilizes equipment |
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Term
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Definition
reduce surface tension of solvents to make them more effective at dissolving solutes
- detergents: charged organic surfactants that are more soluble in water and soaps, good at cleaning but not good disinfectant?
- Quats : antimicrobial, used in many medical and industrial applications, disrupt cell membranes
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Term
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Definition
Salts of mercury, Cu and silver
Silver Nitrate- prevents blindness due to N. gonorrhoeae
Thimerosal-- mercury, preserves vaccines |
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Term
|
Definition
crosslink with amino, hydroxyl, sulfhydryl, and carboxyl grps to denature protiens and inactivate nucleic acids
Glutaraldehyde (2%) disinfects and sterilizes (after long exposure)
Formalin (37%)embalming and disinfects |
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Term
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Definition
ethylene oxide, propylene oxide, beta-proplactone
very toxic and hazardous
used in closed chamber to sterilize medical equipment
denatures protiens and crosslinks of dna
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Term
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Definition
can be used agriculturally, which result in the generation of the MDR strains ?? |
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Term
Prokaryotes v. Eukaryotes |
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Definition
Proks:
- smaller (0.2-2.0 in diameter), no nucleus, no membrane bound organelles
- No cillia
- No cholesterol in their membrane
- they DO have a gycocalyx, flagella that rotates (proton motive force), and fimbriae and pilli
- cell wall: peptidogylcan
- ribosomes: 70s
- chromosomes: usually single, circular no histones no introns
EUK:
- larger, with a nucleus and membrane bound organelles
- they can have a glcocalyx, flagella (undulates, whips - ATP), and cillia
- they do NOT have fimbriae or pilli
- Many have a cell wall: cellulous, algin, agar, carrageenan, silicate, glucosmannan, chitin
- ribosomes: 80s
- chromosomes: usually more than one, linear with histones and introns (most of the time)
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Term
Ways to identify bacteria: |
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Definition
- Shape - this can be misleading depending on phase of growth and nutrition
- arrangement: this is somewhat better - strep (chains) v. staph (clusters)
- requirements for O
- optimal growth temp
- abiltiy to adapt to acidic enviroments
- GRAM STAIN and various other lab test
- nutrient requirements -- and the abilty to obtain this requirements (prototrophic, auxotrophs)
- End product of fermentation: The EMB plate is used to differentiate btw lactose fermentation
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Term
Salmonella typhimurium v. salmonella typhi |
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Definition
same genus, different species, different diseases
one causes typhoid fever the other a gastroenteritis |
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Term
francisella tularensis ssp tularensis |
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Definition
inhalation is usually fatal |
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Term
francisella tularensis ssp. holaritca |
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Definition
inhalation results in mild flu like symptoms |
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Term
francisella tularensis ssp. novicidia |
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Definition
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|
Term
Vibrio cholera serovar O1 and O139 |
|
Definition
Causes epidemic and pandemic cholera |
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Term
Vibrio Cholera serovar non 01 and non 0139 |
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Definition
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