doi:10.1016/j.clinmicnews.2006.03.004

Abstract Campylobacter jejuni is universally recognized as the most common bacterial cause of human gastroenteritis. This organism is also associated with septicemia, meningitis, and the post-infective sequelae of the Guillain-Barré syndrome and reactive arthritis. Interest is increasing in Campylobacter species other than C. jejuni and their roles in human and animal disease. However, these emerging campylobacteria are dramatically under-isolated because of the application of less than optimal laboratory protocols. A Cape Town protocol in which stool is filtered onto antibiotic-free culture media and incubated in a hydrogen-enriched, microaerobic atmosphere is a simple and cost-effective means of optimizing the recovery of all species of Campylobacter, as well as species of the related genera Arcobacter and Helicobacter, from stool, blood, and other clinical samples. Subsequent biochemical identification by means of a flowchart easily identifies presumptive Campylobacter isolates to the species level. As emerging Campylobacter spp. are dramatically under-isolated, the true disease potential of these organisms is unknown at present. , and C. curvus, have an essential growth requirement for hydrogen or formate These Campylobacter species have been isolated from the stools of patients suffering from gastroenteritis, septicemia, and other clinical conditions (3). Hydrogen-dependent organisms are extremely difficult, if not impossible, to recover by the standard culture techniques currently employed in most routine diagnostic laboratories. Some diagnostic laboratories use 42°C as a primary incubation temperature, which allows growth of C. jejuni subsp. jejuni and C. coli but not of other species, such as C. fetus or C. hyointestinalis, which grow at 37°C but not 42°C. C. jejuni subsp. jejuni and C. coli contaminate chicken which has an internal temperature of 42°C. This is probably the historical precedent for using 42°C as a primary incubation temperature. For clinical specimens, it is recommended that incubation at 37°C is a more appropriate temperature, as all Campylobacter spp. infecting humans can be isolated and maintained at this temperature. Up to 17% of clinical samples may have two to five distinct species of Campylobacter or species of the related genera Arcobacter and Helicobacter identified on the primary isolation plate (4). C. jejuni subsp. jejuni may be coisolated with an emerging Campylobacter sp. Different species of Campylobacter and related genera can often be detected initially by differences in colony morpholog