Abstract
Two strains of Ureaplasma urealyticum serotype V that had produced urethritis in human volunteers were, after a number of subcultures in artificial media, introduced intra-urethrally into three chimpanzees. One strain given to two chimpanzees rapidly multiplied 1000-fold whereas there was less evidence that organisms of another strain multiplied in a third animal. Over a 14-day period the ureaplasmas persisted in all animals, did not spread to the throat and did not produce an inflammatory response. After this time they were eliminated by tetracycline therapy.