Division of Mycoplasmas into Subgroups

Abstract

S U M M A R YThe deoxyribonucleic acid (DNA) base compositions of 12 recently isolated or new species of mycoplasmas fell within the range known for the Mycoplasma group. By DNA-DNA hybridization a new sterol-nonrequiring strain, S-743, was unrelated to Mycoplasma laidlawii or M . granularum, the latter two strains showing moderate cross-reactivity ; swine strain B 3 appeared to be related to M . mycoides var. Capri. From these results and information in the literature, the mycoplasmas have been divided into six provisional subgroups on the basis of physiological characters, DNA base composition and nucleic acid hybridization. Some speculations are made on the significance of heterogeneity among mycoplasmas.

A phylogenetic analysis of the mycoplasmas: basis for their classification

“…A sister group relationship between the M. mycoides and Spiroplasma apis clusters was supported by 22 positions of this same type. Even the stricter definition yielded three synapomorphies that supported this particular association.…”

“…Early attempts to subdivide the mycoplasmas, by using immunological approaches, DNA compositions, and the like, proved to be taxonomically useful but gave little phylogenetic information (22,35). On the other hand, rRNA sequences reveal the phylogeny of this group in considerable detail.…”

Physical and genetic mapping of the genomes of five Mycoplasma hominis strains by pulsed-field gel electrophoresis

“…The theoretical number of restriction sites for a restriction enzyme with a 6-base recognition sequence can be calculated on the basis of base composition (G+C = 29 mol% in M. hominis [28]) and genome size (M. hominis genome, -700 kb). BamHI, Sall, and XhoI were thus calculated to cleave the genomes 39 times, and SmaI and ApaI cleaved it 7 times.…”

A taxonomic study of selected avian mycoplasma serotypes utilizing nucleic acid hybridization procedures

“…Neimark (1970) higher GC ratio than most avian species, 32-36%, and are also antigenically distinct. Many of the avian strains were tested by Kelton and Mandel (1969), and since some of their cultures were later found to be mixed, some of their data may not be valid (M. L. Frey, personal communication).…”

“…The work of McGee et al (1967), using the agar column method, showed the reverse, that is, the percent homology was higher (72-90%) when A. laidlawii B was Immobilized than when A. laidlawii B was immobilized (60-67%), suggesting that B DNA was larger. ^ laidlawii A was found to be 33% related to A. qranularum but only 3-6% to another acholeplasma strain s-743 (Neimark, 1970). The s-743 strain was 6% related to the avian strain M. gallisepticum S 6.…”