Campylobacter

Genus of gram-negative spiral-shaped bacteria infecting mammals. Many species, especially C. fetus, cause miscarriage in sheep and cattle. C. jejuni is a common cause of food poisoning. Sources include meats (particularly chicken) and unpasteurized milk. Infection causes acute gastroenteritis, fever, headache, and joint and muscle pain; nerve damage and death may occur in severe cases.

Learn more about Campylobacter with a free trial on Britannica.com.

The genus Campylobacter, (meaning 'twisted bacteria') first discovered in 1963, describes Gram-negative, spiral, microaerophilic bacteria. Motile, with either uni- or bi-polar flagella, the organisms have a somewhat curved, rod-like appearance, and are oxidase-positive. Campylobacter jejuni is now recognised as one of the main causes of bacterial foodborne disease in many developed countries. At least a dozen species of Campylobacter have been implicated in human disease, with C. jejuni and C. coli the most common. C. fetus is a cause of spontaneous abortions in cattle and sheep, as well as it is an opportunisitic pathogen in humans.

Genome

The genomes of several Campylobacter species have been sequenced, providing insights into their mechanisms of pathogenesis. The first Campylobacter genome to be sequenced was C. jejuni, in 2000.

Campylobacter species contain two flagellin genes in tandem for motility, flaA and flaB. These genes undergo intergenic recombination, further contributing to their virulence. Non-motile mutants do not colonize.

Pathogenesis

Campylobacteriosis is an infection by campylobacter. The common routes of transmission are fecal-oral, person-to-person sexual contact, ingestion of contaminated food or water, and the eating of raw meat. It produces an inflammatory, sometimes bloody, diarrhea, periodontitis or dysentery syndrome, mostly including cramps, fever and pain. The infection is usually self-limiting and in most cases, symptomatic treatment by reposition of liquid and electrolyte replacement is enough in human infections. The use of antibiotics, on the other hand, is controversial.

Cause

One cause of the effects of campylobacteriosis is tissue injury in the gut. The sites of tissue injury include the jejunum, the ileum, and the colon. C jejuni appears to achieve this by invading and destroying epithelial cells.

Some strains of C jejuni produce a cholera-like enterotoxin, which is important in the watery diarrhea observed in infections. The organism produces diffuse, bloody, edematous, and exudative enteritis. In a small number of cases, the infection may be associated with hemolytic uremic syndrome and thrombotic thrombocytopenic purpura through a poorly understood mechanism.

References

See also

• Periodontal disease

External links

• Campylobacter info from the CDC