Salmonella species

Salmonellosis

• Gram (-) bacilli
• salmonella food poisoning

Salmonella species

Occurance:

• an infection- gastroenteritis
• is not an intoxication
• 2000 serotypes
• 50,000 cases a year reported (2-3million cases actually occur)
• most commonly reported type of food poisoning

Salmonella species

Resevior:

Mode of transmission:

Incubation period:

• Res- gut of birds, mammals, reptiles (especially turtles)
• MOT- ingestion of food contaminated with salmonella (usually meats, chicken, eggs) and even playing with pets
• IP-8-48 hours usually 42-78 when you ingest very small amount

Salmonella species

Signs/ symptoms:

Diagnosis:

• Fever, abdominal apins, cramps, diarrhea with out vomitting- caused by endotoxin
• symptoms last several day- making it reported more often
• Morbidity(how sick you are)- is high
• Mortality-low except in very old and young or debilitated
• Diagnosis- culture feces

Salmonella species

Treatment:

Immunity:

Prophylaxis:

• treatment: Self limiting, get more fluidsa and elctrolytes
• for bad infections- ampicillin or amoxicillin
• if PCN sensitive or resistant- chloramphenicol
• Immunity: none because 2000 different serotypes
• Prophy: cook chicken well and do not recontaminate cooked chicken with juices
• ppl get sick from eating leftovers
• avoid food with raw eggs- escpecially if cracked...because salmonella is in chicken's where eggs come out
• homemade mayo, egg nog, homemade ice cream never used cracked eggs.
• boil egg 7 min; poach egg 5 min; fried egg 3 min on each side- to kill salmonella

Salmonella typhi

Typhoid fever

Occurance:

Resevior:

Mode of transmission:

Incubation period:

• OCC- aren't common 400-500 cases per year - case fertality rate per year is less than 1%
• RES- gut of Homo sapiens
• MOT- Fecal oral contamination of food or water
• IP-10-14 days because it has to grow

Salmonella typhi

Typhoid fever

Signs symptoms:

Diagnosis:

• fever, abdominal pain, head ache, anorexia
• may spread to other organs through the lymph or blood
• carriers asymptomatic but have bacteria growing in gall bladder where there is poor blood supply-it is hard to kill all bacteria there because poor vascularization- antibiotic wont work there so cholecystectomy is necessary
• typhoid mary- cooked food for people and she intoxicated people with salmonella
• diagnosis: culture salmonella typhi from feces, urine, or blood

Salmonella typhi

Typhoid fever

Treatment:

Immunity:

Prophylaxis:

• Treatment- chloramphenical or ampicillin
• Imm-permanent upon recovery (vaccine available)
• Prophy-cl2 kills salmonella, cl2 in water, avoid carriers, drink pasteurized milk, and isolation of patients

Shigella species

Shigellosis-bacterial dysentery

• Produces endotoxin causing severe inflammation and ulceration of small intestines and colon (others microbes do this also)
• sign/symptoms: fever, nausea, diarrhea, tenesmus (spaz of anal spincter)
• resevior: Homo sapiens
• Mode of transmission: fecal oral contamination that is a big problem in day care centers-affects 11 million kids
• treatment: fluid and electrolytes with antibiotics: ampicillin, tetracycline, chloramphen, TMX-SMX

Escherichia coli

Travelor's diarrhea

Other coliforms:

• Proteus vulgaris
• Serratia marcescens
• Citrobacter freundi

Escherichia coli

Facts:

• Gram(-) bacilli
• More good than bad
• Helps vitamin k absorbtion in the intestines
• only organisim to break down glucose into lactose- through fermentation
• is a fermenter
• creates flatus (gas)

Escherichia coli

Disease causing?

If disease causing produces what?

• Usually does not cause disease in gut but may spread by trauma or poor hygeine (UTI, Vaginitis)
• 15.4% causes nosocomial infection
• May produce enterotoxic food poisoning
• In septicemia the endotoxin may cause endotoxic shock
• presense of E.coli in water means FEC
• Coliform count in lake houston is high!

Escherichia coli

what serotype is extremely virulent and deadly?

• Serotype O157:H7
• causes HUS hemolytic uremic shock
• invasive and will get into blood
• b/c of under cooked food with this serotype or swimming in water contaminated by this
• 5 people died from spinach recall with this in 2006 (more were sick but only old and young died)

Bordetella pertussis

Whooping Cough

"intensive cough"

Occurence:

MOT:

IP:

• Gram (-) bacilli
• 95% of people in the world have had this mild/severe
• US- 2000 to 4000 cases per year with 10 deaths
• 2/3 cases in infants or kids because they do not have the Ab against it yet
• most fatalities less tha 1 year old
• RES: homo sapiens
• MOT- aerosol inhalation
• IP- 7-14 days

Bordetella pertussis

Whooping cough

Signs and symptoms:

• bacteria attach to epitheliem of upper respitory track (PSCCE)
• Do not invade epithelial cells or blood
• produces pertussis toxin (endotoxin)
• causing thick mucus formation (by histamine and serotonin)
• Inhibits ciliary activity
• may kill PSCCE

Bordetella pertussis

Whooping cough

Catarrhal Stage:

• tries to cough of mucus
• 5-15 rapidly consecutive coughs
• whoop on inspiration (hurried and deep)
• may last 1-2 weeks if not treated

Bordetella pertussis

Whooping cough

Paroxymal stage:

• 1-2 weeks uncontrolled coughing fits occur suddenly

Bordetella pertussis

Whooping cough

Convalescense stage:

• may last months
• secondary complications: bronchopneumonia and otidis media

Bordetella pertussis

Whooping cough

Diagnosis:

Treatment:

Immunity:

Prophylaxis:

• DX- cultues methods and serological tests not reliable; acurate diagnosis is difficult but whoop may not present
• TX- erythromycin
• IMM- strong lifetime immunity following infection
• PROPHY- vaccine DPT if under 7
• most people greater than 7 have immunity

Haemophilus influenzae

Non-epidemic meningitis

Occurence:

• #1 cause pf bacterial meningitis- 46%
• Haemophilus influenze 46%
• Neisseria meningitidis 27%
• Streptococcus pneumoniaen 11%
• Case fatality rate is 7%
• orginally thought that it caused flu
• actually causes bronchopneumonia and meninigtis secondary to flu
• 85% of cases are in children less than three

Haemophilus influenzae

non-epidemic meningitis

MOT-

IP-

SX-

• Reservoir: Homo sapiens
• MOT- aerosols enters through nasopharyngeal
• IP- Days 2-4
• SX- fever, vomiting, flu-like symptoms, coma can be common, bulging of fontanels in infants (b/c of accumulation of cerebral spinal fluid in head), stiff neck in children

Haemophilus influenzia

non-epidemic meningitis

Diagnosis-

Treatment-

Immunity-

Prophylaxis-

• DX- isolation of organisms from blood or verebral spinal fluid
• RX- ampicillin and chloramphenicol together
• Immunity- you can from prior infection
• Prophy- HIB vaccine (haemophilus influenza strain B at 18 months
• can also use rifampin to prophy

Haemophilus ducreyi

Chancroid

Occ:

Res:

MOT:

IP:

• OCC- more common in men 83% but women may be carries- occurs mainly in tropics- more common than clap
• Res: Homo sapiens
• MOT- STD
• IP- days

Haemophilus ducreyi

Chancroid

Sign and symptoms:

Diagnosis:

Treatment:

• SX- localized vunereal infection - soft chancre ulcer type lesion
• Not sharply demarcated from the surrounding tissue-PAINFUL (unlike syphilitic chancre- which is hard painless and sharply democrated)
• Treatment: there is no treatment- it amy spread to lymphatics and cause BUBO (large inflammed lymph node- that dark blue from hemorraging)
• Diagnosis- isolation of bacteria from lesion
• Treatment- erythromyocin or TMP-SMX

• Conjunctivitis (pink eye)
• Localized infection of the conjunctiva (bulbar or palpebral)
• Conjunctiva= membrane covering the eye
• Purulent exudate (puss fluid)
• MOT: usually by direct contact, gnats can be vectors
• TX: erythromycin ointment

Yersinia pestis

Occurrence:

Resevoir:

MOT:

IP:

• Bubonic plague (black plague, black death) formerly Pasteurella pestis
• Occ: 25 million Europeans died of this in past; Zoonosis; found in rabbits & rodents; btw. 1974-1983 9 western states reported plague cases to CDC; animals die when sick
• Res: rabbits & rodents
• MOT: direct contact w/ tissues of infected animal; vector=flea, ticks, flies
• IP: 2-6 days

Yersinia pestis

 SN/SX:

DX:

TX:

IMM:

• SN/SX: fever; swollen inguinal (groin) lymph nodes (=BUBO); septicemia may develop spreading to lungs causing plague pneumonia (spread by aerosols) or meningitis
• DX: stained material from bubo, sputum, or CSF; blood tests (FA=flourescent antibodies
• TX: streptomycin, tetracycline, chloramphenicol; without TX 50% die
• Imm: no lasting immunity, vaccination OK but dangerous & requires frequent boosters

• Brucellosis (Undulant Fever)
• Happens in animals
• MOT: Zoonosis- STD spread by animals or other direct contact; unpasteurized milk can cause human infections
• Bacteria live within macrophages & reproduce inside them then spread out- causing endotoxin to be released (results in fever)
• Localizes in rep
• Reproductive organs, causes sterility in males
• *story about man in hospital having sex w/ sheep

• Legionaires disease
• First outbreak in 1957 at Legionaires convention in Minnesota (hence the name)
• Worldwide distribution
• Res: A/C cooling towers & evaporative coolers
• MOT: airborne
• IP: hours-days
• SN/SX: anorexia, malaise, myalgia, HA; does not occur under age 20, common age is 50
• Male/female ratio 5:2
• TX: erythromycin (maybe w/ rifampin)
• Not effective: PCN, cephalosporins, aminoglycosides

Francisella tularensis

EA:

Res:

• Tularemia
• EA: A gram (-) rod becoming pleomorphic, non-motile, obligate aerobe named after the person that discovered the cause of disease & location first found (Tulare, CA); Zoonotic disease occurring in a wide variety of animals including: mammals, birds, fish, ticks & insects, INTRACELLULAR PARASITE; A lipid capsule helps evade phagocytosis
• Res: Found in aquatic ecosystems in temperate areas of Northern hemisphere; rabbits, muskrats, ticks harbor the organism

Francisella tularensis

MOT:

SN/SX:

RX:

• MOT: direct contact w/ infected animal; organism is very small- has ability to pass directly through unbroken skin; ticks pass organism through feces; consumption of contaminated meat or HOH results in disease in gut; inhalation of aerosols causes pulmonary problems
• SN/SX: fever, chills, malaise, fatigue & a skin ulcer at point of infection
• RX: Beta-lactamase provides resistance to PCN & cephalosporins; Doxycycline & ciproflaxacin; CFR 10% in unTX

Top 5 Potential Threats Various Infectious

Agents Pose To Human Beings:

1. Smallpox
2. Anthrax
3. Plague
4. Botulism
5. Tularemia