Base Composition of Deoxyribonucleic Acid from Ureaplasmas Isolated from Various Animal Species

Abstract

The guanine-plus-cytosine (G+C) contents of the deoxyribonucleic acids (DNA) from ureaplasmas (T-mycoplasmas) isolated from several animal species were determined. The values obtained indicate that the G+C content of ureaplasmas is within a range from 26.9 to 31.6 mol%. The distinctness of the DNA G+C content of bovine isolates from that of Ureaplasma urealyticum (the human isolates) is confirmed. The values found for the DNA from canine and feline strains did not distinguish them from U. urealyticum. The caprine and ovine strains have DNA G+C contents similar to but slightly higher than those of the bovine strains. Although the strain isolated from a marmoset has a G+C content that is within the range observed for bovine isolates, the strain isolated from a squirrel monkey has a G+C content that falls between the ranges observed for human and bovine isolates. The results support the suggestion that more than a single species or subspecies exists within the genus Ureaplasma, but more evidence is needed before proposals for new taxa can be made.