Abstract
Eleven Ureaplasma isolates from cattle, chosen to represent the serological diversity of these strains, were compared with the eight serovars (serotypes) of Ureaplasma urealyticum (ureaplasmas from humans) by sodium dodecyl sulfatepolyacrylamide gel electrophoresis of polypeptides labeled by growing organisms in the presence of [35S]methionine. The bovine isolates had many common polypeptides, as did the human isolates. Furthermore, the bovine isolates could be distinguished from the human ones. Within the bovine strains, there appeared to be a relationship between the polypeptides present and the serological structure. The results further support the view that ureaplasmas isolated from cattle should be regarded as a species different from U. urealyticum.