Persistent nongonococcal urethritis associated with a minocycline-resistant strain of Ureaplasma urealyticum: a case report.

Culture of urethral specimens from a 21-year-old man with nongonococcal urethritis yielded both Chlamydia trachomatis and a minocycline-resistant strain of Ureaplasma urealyticum. In such situations, the causal agent of the urethritis is frequently considered to be C. trachomatis. However, the etiology of this case was more probably linked to U. urealyticum. This conclusion emerged after observation of the following events: (1) the patient was not cured by a standard course of minocycline, despite the elimination of the chlamydiae; and (2) clinical recovery was achieved by treatment with a different drug (erythromycin), to which the ureaplasmas were susceptible and by which they were eradicated.