Mycoplasma hominis: historical outline and taxonomy

Although known as a separate group of organisms since 1898, the isolation in 1937 of a human genital mycoplasma represented the first observation of the association of this group of organisms with humans, a discovery that provided the impetus for extensive investigations of the interactions of mycoplasmas with the human host. These studies showed that mycoplasmas were frequent inhabitants of the mucous membranes of the urogenital and upper respiratory tracts. In early studies of human mycoplasmas, they were not speciated but were assigned to this group of organisms almost exclusively on the basis of cultural characteristics. However, differentiation between groups of human genital and oral mycoplasmas based on cultural, morphologic, biochemical, and serologic properties was achieved in 1953. A few years later formal proposals for the establishment of three human species of Mycoplasma (including Mycoplasma hominis) were made, along with suggestions for a new classification and nomenclature of the mycoplasmas. Serologic, genetic, and other data clearly show that M. hominis does constitute a relatively heterogeneous group of organisms. However, although this heterogeneity has practical implications for identification of isolates of M. hominis and for demonstration of antibodies to M. hominis, further studies are necessary to justify formal recognition of a taxonomic subdivision of M. hominis into distinct serovars. Investigations of the role of M. hominis as a potential human pathogen date back to the very first years of its discovery.(ABSTRACT TRUNCATED AT 250 WORDS)