Human Intra-urethral Inoculation of Ureaplasmas D. TAYLOR-ROBINSON, G. W. CSONKA,1 AND

Ureaplasma urealyticum was isolated from two men suffering from non-specific urethriti8 and from whom no other micro-organisms were recovered. Their disease responded to tetracycline. The two ureaplasma strains were cloned and shown to belong to serotype 5 of U. urealyticum. An inoculum containing 5 x 10 * colour-changing units of one strain was introduced intraurethrally into a subject (an author) who was free of ureaplasmas and other urethral micro-organisms. The urea-plasmas multiplied in the urethra and the subject soon experienced symptoms of dysuria. Furthermore, polymorphonuclear leucocytes were found in centrifuged aliquots of urine and a serum metabolism-inhibition antibody response of short duration was detected. Tetracycline given six days after inoculation brought about rapid clearance of organisms from the urine and a more gradual disappearance of symptoms and signs. Inoculation of ureaplasma-free medium about two months after the initial introduction of ureaplasmas did not elicit symptoms or signs. These observations showed that the ureaplasmas had produced urethritis. Organisms of the other ureaplasma strain were introduced in the same number and in the same way int