Tetracycline-resistant Mycoplasma hominis strains contain streptococcal tetM sequences

Clinical isolates of Mycoplasma hominis resistant to high levels of tetracycline contained DNA sequences homologous to the streptococcal tetracycline determinant, tetM. In contrast, none of the susceptible M. hominis isolates tested carried this determinant. This is the first description of tetM in an unrelated genus and suggests the spread of tetM from Streptococcus spp. to Mycoplasma spp.