The phylogenetic relationships of all species in the genus
Campylobacter, Wolinella succinogenes, and other gram-negative bacteria were determined by comparison of partial 16S ribosomal ribonucleic acid sequences. The results of this study indicate that species now recognized in the genus
Campylobacter make up three separate ribosomal ribonucleic acid sequence homology groups. Homology group I contains the following true
Campylobacter species:
Campylobacter fetus (type species),
Campylobacter coli,
Campylobacter jejuni,
Campylobacter laridis,
Campylobacter hyointestinalis,
Campylobacter concisus,
Campylobacter mucosalis,
Campylobacter sputorum, and