Arcobacter

Campylobacters were Šrst isolated at the beginning of the twentieth century. In 1913, McFadyean and Stockman isolated Vibrio-like organisms from aborted ovine fetuses.1 Five years later, Smith described the isolation of Vibrio/Spirillumlike organisms from aborted bovine fetuses, which he considered as the same species as described by McFadyean and Stockman.2 Although the cell shape of the those organisms was characteristic of the family Vibrionaceae, they failed to ferment carbohydrates, and were therefore transferred into a new genus, Campylobacter.3 Seventy years later, Ellis et al.,4,5 and Higgins and Degre,6 reported the isolation of aerotolerant, spiral-shaped Campylobacter-like organisms from the organs of porcine and bovine fetuses. Examination of all Campylobacter and Campylobacter-like isolates revealed two distinct biochemical groups: the group 1 isolates were identiŠed as Campylobacter fetus, whereas the group 2 isolates were considered as the “aerotolerant campylobacters.”7,8 In a comprehensive study in 1985, Neill et al.9 provided a thoroughly documented description for a new species, Campylobacter cryaerophila, to include these “aerotolerant campylobacters” but also emphasized their phenotypic heterogeneity. In 1988, Thompson et al.10 showed by partial 16S rRNA sequence analysis that C. cryaerophila and Campylobacter nitroƒgilis, an organism isolated from the roots of Spartina alterni§ora, exhibited more

homology with each other than with other campylobacters, suggesting that classiŠcation of both C. cryaerophila and C. nitroƒgilis in another genus would be appropriate. In the early 1990s, Kiehlbauch et al.11 found two subgroups among C. cryaerophila strains by phenotypic characterization and DNA-DNA hybridization. Catalase-positive strains that were able to grow under aerobic conditions at 30°C but not in a medium with glycine or on MacConkey agar were considered as C.  cryaerophila. The name Campylobacter butzleri was proposed for the aerotolerant isolates that were negative to weakly catalase positive, and for which growth was observed in glycine minimal medium an on MacConkey agar. In 1991, after a polyphasic taxonomic study, Vandamme et al.12 transferred C. cryaerophila and C. nitroƒgilis into a new genus, Arcobacter. Subsequently, C. butzleri was reclassiŠed as Arcobacter butzleri and Arcobacter skirrowii was proposed for yet another group of animal associated Arcobacter strains.13