Campylobacter is a curved, gram-negative rod that is microaerophilic, capnophilic, and thermophilic. It is motile with a single polar flagellum and is the most common cause of foodborne bacterial diarrhea in developed countries. Campylobacter jejuni is transmitted via the fecal-oral route from infected animals to humans through contaminated food or water. Symptoms include watery diarrhea, abdominal pain, and fever. Complications can include Guillain-Barré syndrome. Laboratory diagnosis involves culturing stool or blood samples under microaerophilic conditions at 42°C. Treatment is usually with erythromycin or ciprofloxacin.

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.