Classification and identification of Campylobacters, Helicobacters and allied taxa by numerical analysis of phenotypic characters

The value of numerical analysis of phenotypic characters for the classification and identification of campylobacteria was investigated. Sixty-seven phenotypic characters were determined for 347 strains representing forty-three species, subspecies, biovars or unnamed groups assigned or affiliated to the genera Campylobacter, Arcobacter, Helicobacter, and Anaerobiospirillum. The data were subjected to numerical analysis using a computer program, MVSP. The results indicated that, (i) there was considerable agreement between the groupings obtained and previously determined genomic relationships, (ii) most strains could be identified accurately to the specific or subspecific level, and (iii) two novel groups could be delineated. Although highly atypical strains proved difficult to classify, the method has considerable potential for accurately differentiating members of this taxonomically complex and economically important group of bacteria.