Isolation of mycoplasmas from prairie voles (Microtus ochrogaster)

A new species of mycoplasmas was isolated from the lungs and nasopharyngeal washings of prairie voles (Microtus ochrogaster). Clinical signs of disease and microscopic lesions were not observed at the time of this isolation. The organism was cultured in SP4 medium; it grew aerobically, anaerobically, and in 5% CO₂ in 5 to 7 days, and fermented glucose. Transmission electron microscopy revealed the organism to lack a cell wall and to have typical mycoplasmal ultrastructural morphology. The complete nucleotide sequence of the 16S rRNA gene from an isolate was determined by amplification with polymerase chain reaction and by sequencing with the dideoxynucleotide chain termination method. The sequence did not match any known sequences in the GenBank of the National Institutes of Health. The 16S rRNA sequence of the organism, Mycoplasma volis (proposed species novum), is unique and most closely resembles that of M. muris and M. iowae. Because this vole colony will be housed in rooms with other rodents, pathogenicity studies of this new species of mycoplasmas in mice and rats are underway.