1. CAMPYLOBACTER
IMPORTANT PROPERTIES -
Curved, Gram -ve rod.
Convert to coccoid shape w hen exposed to O2 or prolonged presence in culture.
Micro-aerophilic
5% O2.
Capnophilic.
10% CO2
Thermophilic (can grow at 42C == > selectivity)
Motile.
Single Polar Flagella.
Non-Spore forming.
Oxidase +ve.
Catalase +ve.
Reduction of Nitrates to nitrites.
H2S production.
Neither ferment nor oxidize glucose or carbohydrates.
IMPORTANT SPECIES
C.jejuni.
C.intestinalis.
PROTOTYPE SPECIES: -
C.jejuni.
PATHOGENESIS: -
Diseases:-
Diarrhea
Systemic Infections.
Sources: -
Domestic animals e.g cattle, chicken, dogs etc.
Transmission: -
Feco- oral route.
Food & w ater contaminated w ith animal feces --- major sources of human infection.
Unpasteurized milk.
Putative Virulence Factors:-
Cellular Components: -
Endotoxin.
Flagellum: - Motility
Adhesins: Mediate attachment to mucosa.
Invasins.
S-layer protein microcapsule(C.fetus)
Extracellular Components:-
Exterotoxin.
Cytopathic toxins.
Not significant.
ID50: -
10,000 organisms since it is susceptible to gastric acid.
Mechanism: -
Multiplication in small intestine÷
Invasion of epithelium÷
Inflammation of Intestinal mucosa.
Blood (RBC’s & WBC) in stools (may be)
Systemic infection ( in neonates and debilitated adults).
Self limited to 5-8days but can prolong.
CLINICAL FINDINGS: -
Enterocolitis (C.jejuni): -
Watery foulsmelly diarrhea follow ed by ÷
Bloody stools accompanied by ÷
Fever and severe abdominal pain.
Systemic Infection(C.intestinalis)
Bacteremia:-
2. Symptoms like malaise and fever are not associated with any physicalfinding.
Sequele to infection:-
Post-diarrheal Guillain – Barre Syndrome(C.jejuni serotype O19):-
Mechanism: -
Formation of autoantibodies takes place w hich crossreactswith antigens on neurons.
Most common cause of acute neuromuscular paralysis.
Reiters Syndrome :- Autoantibodies
Reactive arthritis.: - Autoantibodies
LABORTARY DIAGNOSIS: -
Specimens: -
Stool (diarrhea)
Blood (Bacteremia)
Smear: -
Typical Gull w ing shaped rods.
Microscopy:-
Dark field or phase contrast microscopymy show darting motility of the organisms.
Culture:-
Blood Agar Plate (Skirrow ’s Medium).
Procedure: -
Incubation temperature: - 42C though C.jejuni can grow at 37C but 42C prevents other bacteria in stool to grow.
Micro-aerophilic environment 5%O2 and 10CO2%, in anaerobic incubation jar w ithout catalyst and to produce
the gas w ith commercially available gas pack.
Colony Characteristics:-
Colourless, grey w atery,
Spreading, round, convex.
Both types of colony may appear on a single plate.
Identification: -
C.jejuni: -
Failure to grow at 25C.
Oxidase Positivity.
Sensitivity to naldixic acid.
Hippurate hydrolysis - +ve
C.intestinalis: -
Failure to grow at 42C.
Ability to grow at 25C.
Resistance to naldixic acid.
Bacteremia:-
Specimen: - blood
Comma shaped, motile, gram -ve rods.
TREATMENT: -
Erythromycin.
Ciprofloxacin.
PREVENTION: -
No vaccine.
Proper sew age disposal.
Personal hygienic care.