Campylobacter

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(microbiology) A genus of bacteria in the family Spirillaceae; spirally curved rods that are motile by means of a polar flagellum at one or both poles.

A genus of pathogenic organisms which are the most commonly reported cause of gastro-enteritis in the UK, although it is not known what proportion of cases are foodborne. Campylobacteriosis has been associated with the consumption of undercooked meats, milk that has been inadequately pasteurized or contaminated by birds, and contaminated water.

A microorganism associated with progressive periodontal destruction and refractory forms of periodontitis.

Although campylobacter was first identified in 1909 as an animal pathogen, due to better isolation methodology in recent years it is now recognized as one of the leading causes of diarrhea in humans. They are small nonsporing, gramnegative motile bacteria with spiral or S-shaped morphology and can only grow under conditions of reduced oxygen tension. Campylobacter organisms are sensitive to drying or freezing, but they can survive in the environment in cold ground-water, soil, and in refrigerated food for weeks. Campylobacters are found in the gastrointestinal tract of domestic and wild animals and can cause human infections through direct contact or through food or water vehicles. Poultry, cattle, swine, and sheep are the main reservoirs, and campylobacters can cause abortions and diarrhea in these animals.

Two main species affect humans, C. jejuni and C. coli, with most cases attributed to the former. Virulence factors include rapid motility, outer membrane protein for adherence, and possibly enterotoxin. The diarrhea caused by campylobacter is often mild, but may be marked by profuse, foul-smelling stools with blood or mucus, accompanied by abdominal cramping. Symptoms can be severe enough to mimic appendicitis, although death is rare. Sequelae such as reactive arthritis may follow, but the most serious of these is Guillain-Barré syndrome. For these reasons, the costs for campylobacteriosis are high (up to $1.4 billion annually in the United States). Immunocompromised people are susceptible, and young adults also appear to be a high-risk group, possibly due to inadequate understanding of food safety and undercooking of poultry. Based on routine surveillance, children under five years of age have the highest incidence.

Most campylobacteriosis cases are sporadic, peaking in the summer months. The estimated annual incidence of campylobacteriosis in the United States and United Kingdom is about the same, between 1,000 and 1,100 cases per 100,000 persons. In developing countries the rate is believed to be higher, especially in children under five. Risk factors include direct contact with farm animals, animal carcasses, or household pets— especially puppies and kittens with diarrhea. Person-to-person transmission occurs within families. Perinatal transmission is rare. Unlike Salmonella and other food-borne disease organisms, Campylobacter subspecies tend not to multiply in food, but they can be found in large numbers in raw sewage and fecally contaminated surface waters. Raw chicken is the food most commonly associated with campylobacteriosis. Because of the low infective dose, it is possible to transfer sufficient organisms to the mouth by direct contact with the chicken or its drip waters to cause illness.

In addition, consumption of untreated water and milk has been associated with large outbreaks— 500 joggers in Switzerland became ill after drinking a raw milk beverage, and 2,500 school children aged 2 to 7 were infected by raw milk in England. In Sweden, between 1992 and 1996, six waterborne outbreaks were recorded, affecting about 6,000 persons. Water treatment, pasteurization of milk, and proper hygiene by the public are the most important strategies for reducing incidence of the disease.

(SEE ALSO: Food-Borne Diseases; Waterborne Diseases)

Bibliography

Advisory Committee on the Microbiological Safety of Food (1993). "Interim Report on Campylobacter." London, UK: Her Majesty's Stationery Office.

Center for Food Safety and Applied Nutrition (2001). "Campylobacter jejuni." In Bad Bug Book (Foodborne Pathogenic Microorganisms and Natural Toxins Handbook). Washington, DC: U.S. Food and Drug Administration. Available at http://vm.cfsan.fda.gov/~mow/chap4.html.

Farber, J. M., and Todd, E. C. D., eds. (2000). Safe Handling of Foods. New York: Marcel Dekker.

— EWEN TODD

For more information on Campylobacter, visit Britannica.com.

A genus of bacteria, family Spirillaceae, made up of gram-negative, non-spore-forming, motile, comma-shaped rods, which are microaerophilic to anaerobic. Members of the genus were previously classified as Vibrio spp. and many of the diseases caused by these species are still referred to as vibriosis.

• C. coli — a commensal of the gastrointestinal tract of poulty, pigs and humans; can cause enteritis in pigs and humans.
• C. fetus subsp. fetus — causes ovine genital campylobacteriosis and abortion in sheep and cattle.
• C. fetus subsp. venerealis — causes bovine vibriosis, also known as epizootic bovine infertility.
• C. hyointestinalis, C. mucosalis — associated with the porcine intestinal adenomatosis complex, proliferative hemorrhagic enteropathy, necrotic enteritis.
• C. jejuni — causes abortion in sheep and enteritis in dogs, cats and other animals. An important food-borne cause of enteritis in humans, and the cause of avian vibrionic hepatitis.
• C. sputorum subsp. bubulus, C. sputorum biovar fecalis — found in cattle and sheep, but not known to cause disease.
• C. upsaliensis — may be associated with diarrhea in dogs and humans.

Campylobacter
SEM micrograph of C. fetus
Scientific classification
Kingdom: Bacteria Phylum: Proteobacteria Class: Epsilon Proteobacteria Order: Campylobacterales Family: Campylobacteraceae Genus: Campylobacter Sebald and Véron 1963
Species
C. coli C. concisus C. curvus C. fetus C. gracilis C. helveticus C. hominis C. hyointestinalis C. insulaenigrae C. jejuni C. lanienae C. lari C. mucosalis C. rectus C. showae C. sputorum C. upsaliensis

The genus Campylobacter are 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.^[1] Campylobacter jejuni is now recognised as one of the main causes of bacterial foodborne disease in many developed countries.^[2] At least a dozen species of Campylobacter have been implicated in human disease, with C. jejuni and C. coli the most common.^[1] C. fetus is a cause of spontaneous abortions in cattle and sheep, as well as an opportunisitic pathogen in humans.^[3]

Genome

The genomes of several Campylobacter species have been sequenced, providing insights into their mechanisms of pathogenesis.^[4]

Campylobacter species contain two flagellin genes in tandem for motility, flaA and flaB. These genes undergo intergenic recombination, further contributing to their virulence. ^[5] Non-motile mutants do not colonize.

Pathogenesis

Main article: Campylobacteriosis

Campylobacteriosis is an infection by campylobacter ^[6]. The common routes of transmission are fecal-oral, person-to-person sexual contact, ingestion of contaminated food or water. It produces an inflammatory, sometimes bloody, diarrhea, periodontitis ^[7] 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

This is most commonly caused by C. jejuni, a spiral and comma shaped bacterium normally found in cattle, swine, and birds, where it is non-pathogenic. But the illness can also be caused by C. coli (also found in cattle, swine, and birds) C. upsaliensis (found in cats and dogs) and C. lari (present in seabirds in particular).

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

1. ^ ^{a b} Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill, pp. 378–80. ISBN 0838585299. 
2. ^ Moore JE, et al. (2005). "Campylobacter". Vet Res 36 (3): 351-82. PMID 15845230. 
3. ^ Sauerwein R, Bisseling J, Horrevorts A (1993). "Septic abortion associated with Campylobacter fetus subspecies fetus infection: case report and review of the literature". Infection 21 (5): 331-3. PMID 8300253. 
4. ^ Fouts DE et al. (2005). "Major structural differences and novel potential virulence mechanisms from the genomes of multiple Campylobacter species". PLoS Biol 3 (1): e15. DOI:10.1371/journal.pbio.0030015. PMID 15660156. 
5. ^ Grant C, Konkel M, Cieplak W, Tompkins L (1993). "Role of flagella in adherence, internalization, and translocation of Campylobacter jejuni in nonpolarized and polarized epithelial cell cultures". Infect Immun 61 (5): 1764-71. PMID 8478066. 
6. ^ cdc.gov
7. ^ Humphrey, Tom et al. (2007). "Campylobacters as zoonotic pathogens: A food production perspective <internet>". International Journal of Food Microbiology 117 (3). DOI:10.1016. 

See also

• Periodontal disease

External links

• Campylobacter info from the CDC

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