What is Campylobacter?
Campylobacter is a genus of bacteria that is among the most common causes of bacterial diarrheal illness in humans worldwide. The name means “curved rod,” derived from the Greek campylos (curved) and baktron (rod). While there are dozens of species, three represent the main sources of human infection: Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. C. jejuni is the most commonly implicated species.
Campylobacteriosis as a disease entity was first recognized by Theodor Escherich in 1886, who described the symptoms of intestinal Campylobacter infections in children as “cholera infantum” or “summer complaint.” However, the organisms were not easily cultured or characterized, which precluded their recognition as major causes of disease until the 1970s.
Campylobacter jejuni is a gram-negative rod-shaped bacterium that grows best in a high temperature (42°C, or 107°F) and low oxygen environment. These characteristics represent adaptations to growth in its normal habitat—the intestines of warm-blooded birds and mammals. Several closely-related bacterial species with similar characteristics, C. coli, C. fetus, and C. upsalienis, may also cause disease in humans but are responsible for less than 1% of human infections annually. The optimal conditions required for the growth of Campylobacter make it difficult to isolate in the laboratory from fecal specimens without special techniques, including the use of selective culture media.