Nucleic acid relationships among the anaerobic mycoplasmas.

The genetic relatedness between twelve selected strains among four distinct serovars of anaerobic mycoplasmas was studied using [3H]DNA-DNA hybridization, and the results were compared with data obtained from biochemical and serological tests. Radiolabelled DNA probes were prepared from five strains representing four serovars. Based on the homology results, the anaerobic mycoplasmas can be divided into five distinct groups representing five distinct species and two distinct genera. There are two species in the Anaeroplasma bactoclasticum serovar 1 group represented by strains JR and A-2, one species in serovar 2, one species in A. abactoclasticum serovar 3 and one among the unclassified serovar 4 anaerobic mycoplasmas. The probe to nonsterol-requiring strain 161 of serovar 4 showed no homology with any of the established nonsterol-requiring Acholeplasma species DNAs, or with Mycoplasma hominis DNA, or with avian DNA which served as a negative control. There was good correlation between the phenotypic and genotypic properties of the five distinct anaerobic mycoplasma species but the results indicate that phenotypic properties are not always adequate for speciation of the anaerobic mycoplasmas.