Campylobacter and Arcobacter

Abstract

Three closely related genera, Campylobacter , Arcobacter , and Sulfurospirillum , are included in the family Campylobacteraceae . Originally classified as free-living Campylobacter species, Sulfurospirillum spp. are slender, curved gram-negative rods, 0.1 to 0.5 mm wide and 1 to 3 µm long. These species have no known pathogenicity for humans or animals, and are environmental organisms isolated from water sediments. Arcobacter spp. are aerotolerant, Campylobacter -like organisms frequently isolated from bovine and porcine products of abortion and feces of animals with enteritis. Arcobacter butzleri was reported to be the fourth most common Campylobacter -like organism isolated from patients with diarrhea and was also one of the most common non C. jejuni / coli species isolated over a 10-year period from over 73,000 stool samples. The Gram stain appearance of Arcobacter may differ from that of typical Campylobacter . Unfortunately, Campylobacter species are difficult to differentiate from Arcobacter species based on phenotypic tests. The 16S rRNA gene and 23S rRNA gene are widely used for genus-and species-specific tests. PCR assays based on these targets are described for 12 different Campylobacter species and three Arcobacter species. Broad-range molecular identification schemes involving restriction fragment analysis of PCR-amplified regions of the 16S or 23S rRNA genes have also been described for identification of Campylobacter and Arcobacter species. Special methods including alternative incubation techniques are required and should be performed by special request.