f Mycoplasma sualvi, a New Species from the Intestinal and Urogenital Tracts of Pigs

Eight similar Mycoplasma isolates were obtained from rectal, intestinal, and vaginal specimens from pigs. Two indistinguishable clones of one isolate (May-field) were examined in detail. Although closely resembling the cattle organism Mycoplasma alvi in cultural and biochemical properties, the Mayfield clones differed from this species in morphological appearance and deoxyribonucleic acid base composition. The clones were serologically distinct from M. alvi and 58 currently recognized Mycoplasma species and subspecies, including all of those having similar biochemical properties or the same host. The Mayfield strain clone B (NCTC 10170) is designated the type strain of a new species, M. sualvi, which includes five of the seven other Mycoplasma isolates from pigs. The remaining two isolates appear to be serologically dissimilar from the Mayfield strain.