Persistence of ureaplasma urealyticum in the genital tract after antibiotic therapy.

Urine samples from 65 couples attending an infertility clinic were tested for the presence of Ureaplasma urealyticum. Of 36 couples found to harbor the organism, 35 were given antibiotic treatment in an attempt to eradicate these organisms from the genital tract. After the initial antibiotic therapy, tests of 12 of 27 couples (44%) still were Ureaplasma positive; after a second course of treatment, tests for 4 of 9 were positive. Two couples had Ureaplasma organisms that were resistant to all antibiotics tested. One couple remained positive after five courses of treatment, in spite of the demonstrated in vitro sensitivity of the isolate to antibiotics used. Pregnancies in treated patients occurred among those who were Ureaplasma negative after doxycycline therapy.