ARCOBACTER-SPECIFIC AND ARCOBACTER BUTZLERI-SPECIFIC 16S RIBOSOMAL-RNA-BASED DNA PROBES

The genus Arcobacter encompasses gram-negative, aerotolerant, spiral-shaped bacteria formerly designated Campylobacter cryaerophila. Two genus-specific 16S rRNA-based oligonucleotide DNA probes (23-mer and 27-mer) were developed. The probes hybridized with strains of Arcobacter butzleri (n = 58), Arcobacter cryaerophilus (n = 19), and Arcobacter skirrowii (n = 17). The probes did not cross-react with any of the reference strains of Campylobacter, Helicobacter, including ''Flexispira rappini,'' or Wolinella. The 27-mer hybridized with, 61 Arcobacter spp. field isolates originating from late-term aborted porcine (n = 54) and equine (n = 2) fetuses and humans with enteritis (n = 5). The species of Arcobacter isolates (n = 56) recovered from aborted livestock fetuses were determined by ribotyping and were as follows: A. cryaerophilus group 1A (11 of 56; 20%), A. cryaerophilus group 1B (37 of 56; 66%), A. butzleri (5 of 56; 9%), and unknown (3 of 56; 5%). The five human field strains were identified as A. butzleri. A species-specific DNA probe (24-mer) for A. butzleri was also developed since there is evidence that this organism may be a human pathogen. This probe hybridized with previously characterized strains of A. butzleri (n = 58), with 10 field strains identified as A. butzleri by ribotyping and with 2 strains having an indeterminate ribotype. The A. butzleri-specific probe did not crossreact with strains of A. skirrowii (n = 17) and A. cryaerophilus (n = 19).