Campylobacter

Campylobacter Jejuni and other Enteric Campylobacters
? Clinical Manifestations
Campylobacter species cause acute gastroenteritis with diarrhea, abdominal pain, fever, nausea, and vomiting. Recently, Campylobacter infections have been identified as the most common antecedent to an acute neurological disease, the Guillain-Barré syndrome.
? Structure
Campylobacter species are Gram-negative, microaerophilic, non-fermenting, motile rods with a single polar flagellum; they are oxidase-positive and grow optimally at 37° or 42°C.
? Classification and Antigenic Types
Campylobacter species have many serogroups, based on lipopolysaccharide (O) and protein (H) antigens. However, only a few serogroups account for most human isolates in a given geographic region. C jejuni possesses several common surface-exposed antigens, including porin protein and flagellin.
? Pathogenesis
The bacteria colonize the small and large intestines, causing inflammatory diarrhea with fever. Stools contain leukocytes and blood. The role of toxins in pathogenesis is unclear. C jejuni antigens that cross-react with one or more neural structures may be responsible for triggering the Guillian-Barre syndrome.
? Host Defenses
Nonspecific defenses such as gastric acidity and intestinal transit time are important. Specific immunity, involving intestinal immunoglobulin (IgA) and systemic antibodies, develops. Persons deficient in humoral immunity develop severe and prolonged illnesses