Association of Ureaplasma urealyticum (Biovar 2) with nongonococcal urethritis

Background: The tiny (T)-strain mycoplasmas, designated in 1974 as Ureaplasma urealyticum, have been divided into 2 species, Ureaplasma parvum (biovar 1) and U. urealyticum (biovar 2), but association of each of these species with nongonococcal urethritis (NGU) remains unclear. Goal: The goal of this study was to determine whether U. parvum (biovar 1) or U. urealyticum (biovar 2) is associated with NGU. Study Design: The prevalences of U. parpum (biovar 1) and U. urealyticum (biovar 2) in 572 patients with urethritis were compared with those in 141 men without urethritis. Results: The prevalence of U. urealyticum (biovar 2) in men with NGU (15.8%) or with nonchlamydial NGU (18.0%) was significantly higher than that in men without urethritis (7.8%). The prevalence of U. parvum (biovar 1) in men with NGU (8.5%) or with nonchlamydial NGU (11.1%) did not differ significantly from that in men without urethritis (13.5%). Conclusion: Our results showed a significant association between U. urealyticum (biovar 2) and NGU. They also suggest that the presence of U. parvum (biovar 1) in the male urethra might be the result of colonization.