ALL - Other Gram Negative Rods

Pseudomonas aeruginosa

large GNR; not fastidious and grows on MacConkey agar; found in water, soil, and plants; oxidase positive, opportunistic

What are the populations most at risk from P. aeruginosa?

immunocompromised individuals, cystic fibrosis patients; and swimmers

What are the toxins produced by P. aeruginosa, and what disease does these bacteria cause?

lipid A endo toxin; causes fever, inflammation, and shock

Francisella tularensis

causes Tularemia/Rabbit Fever; acquired through ingestion; bug bites; aerosols; wounds; Biosafety III Lab

Legionella

spread by aerosolized contaminated water; requires L cysteine for growth, iron enhance growth, grows on BCYE or Chocolate agar

BCYE agar

Buffered Charcoal Yeast Extract media; yeast is rich in L cysteine and iron

What made the Legionnaires uniquely susceptible to this disease?

they were older, male, smokers, and immunocompromised

Coxiella burnetti

the most infectious disease in the world; most common endocarditis in Australia; causes Q fever, animals contract it through tick bites - humans inhale it; DOC is tetracycline

Bacteroides fragilis

most common bile resistant anaerobic gram negative rod isolated in peritonitis; normally found in colon

Prevotella species

Bile sensitive anaerobic gram negative rod; causes periodontal and pelvic infections; found in sinus, ear

Bartonella henselae

causes Cat Scratch Disease

Bartonella sp.

causes Trench fever; spread by lice

Brucella species

causes brucellosis(undulant fever) in animals; Biosafety level III pathogen

brucellosis

results in abortion/stillbirth in mammals

Bordetella pertussis

causes Whooping cough; specimen collected with cough plates and grown on 20% horse blood media

adenylate cyclase toxin

excreted by B. pertussis; stops cilia from beating

Whooping cough(Pertussis)

a highly contagious respiratory tract infection

The stages of whooping cough are:

1. Incubation: 7-10 days

2. Catarrhal: cold like symptoms/cough gradually gets worse

3. Paroxysmal: severe coughing that can break ribs

4. Convalescent: cough becomes less severe

Fastidious bacteria

requires unusual or many types of nutrients to grow; cannot grow on MacConkey agar (despite being GNR) and sometimes 5% sheep blood agar

Pasteurellaceae Family

GNR; requires heme or cytochromes; includes Pasteurella and Haemophillus - both are fatidious

heme

iron containing molecule in hemoglobin; X factor

cytochromes

protein associated with heme

NAD

V factor

Pasteurella multocida

causes Cat Bite Infection; common normal flora in the mouths of animals

Haemophilus species

requires XV factors; only grows on chocolate agar

Chocolate agar

made by heating blood agar until RBC rupture and release XV factors

Haemophilus influenzae type b (H. flu/Hib)

causes pneumonia, bacteremia, meningitis, ear infections, epiglottis, cellulitis, and infectious arthritis; has capsule

Haemophilus aegyptius

causes pink eye and Brazilian purpuric fever

Haemophilus ducreyi

causes chancroid or soft chancre; STD