Longitudinal Quantitative Detection by Real-Time PCR of Mycoplasma genitalium in First-Pass Urine of Men with Recurrent Nongonococcal Urethritis

Abstract

By using a TaqMan assay we monitored longitudinal changes in Mycoplasma genitalium loads in five men with recurrent M. genitalium-positive nongonococcal urethritis. We observed regrowth of M. genitalium persisting in hosts after treatment and a possible association of the increase in the M. genitalium load with emergence of symptoms and signs of nongonococcal urethritis in four of these patients.In 1981, when Mycoplasma genitalium was initially identified, two strains were isolated from two urethral specimens in culture (16). Despite repeated attempts to isolate M. genitalium from the urogenital tract, however, culture of M. genitalium is still immensely difficult. In the 1990s, the advent of PCR-based assays facilitated studies on the association of M. genitalium with acute nongonococcal urethritis (NGU) (9, 11). This mycoplasma has been detected significantly more often in patients with acute NGU, particularly in patients with nonchlamydial NGU, than in subjects without urethritis (6,8). In 2002 we developed a TaqMan assay for quantification of M. genitalium DNA and quantified M. genitalium in first-pass urine of men with urethritis and of asymptomatic men (17). We reported that the M. genitalium load was significantly higher in men with acute nonchlamydial NGU than in asymptomatic men (17). The various results reported to date suggest that M. genitalium may be associated with the development of acute NGU independent of Chlamydia trachomatis (2, 13).For chronic NGU, it has been suggested that persistence of M. genitalium in the urethra after antimicrobial chemotherapy might be associated with this condition (5,7,10,15). However, quantitative analysis of M. genitalium has been not performed in cases of chronic NGU. In the present study, therefore, we used the TaqMan assay to monitor longitudinal changes in M. genitalium loads in patients with recurrent NGU and to examine those cases for association of the M. genitalium load with clinical findings and inflammatory responses.Five men with recurrent NGU, who had been included in a previous study (10), were enrolled in the present study. They attended the Department of Urology, Toyota Memorial Hospital, Toyota, Japan, between July 1999 and December 2001. Each of these patients had symptoms and signs consistent with acute urethritis at the first visit. For each patient, Gramstained urethral smears showed five or more polymorphonuclear leucocytes (PMNLs) per high-power (ϫ1,000) microscopic field in at least three fields. Urine specimens were subjected to AMPLICOR STD-1 assay (Roche Diagnostics, Indianapolis, Ind.) for detecting Neisseria gonorrhoeae and C. trachomatis and to a PCR-and phylogeny-based assay for detecting mycoplasmas and ureaplasmas. The AMPLICOR STD-1 assay was done according to the manufacturer's instructions. The PCR-and phylogeny-based assay, which could detect at least 10 copies of the 16S rRNA gene of M. genitalium, was done as described in our previous report (18). Two patients were positive for both C. trachomatis and M. genitalium, and three w...

Performance of the Gen-Probe Transmission-Mediated Amplification Research Assay Compared to That of a Multitarget Real-Time PCR for Mycoplasma genitalium Detection

“…PCR detection requires only DNA, alleviating the need for viable organisms. Real-time PCR methodology has further improved MG detection (3,7,8,12,14,29). Real-time PCR couples simultaneous amplification and detection, resulting in shorter assay time and increased sensitivity and obviating the need for post-PCR processing that is required for traditional PCR assays.…”

Experimental Infection of Pig-Tailed Macaques (Macaca nemestrina) with Mycoplasma genitalium

“…In men, M. genitalium is a frequent cause of acute and chronic nonchlamydial nongonococcal urethritis (1)(2)(3)(4), and in women, M. genitalium is increasingly recognized for its role in cervicitis, pelvic inflammatory disease, preterm birth, and spontaneous abortion (reviewed in reference 5). Additional studies have implicated M. genitalium in tubal factor infertility (6,7) and endometritis (8).…”

Antimicrobial chemotherapy ofMycoplasma genitalium-positive non-gonococcal urethritis

“…This patient had a later recurrence of NGU. In these five men with recurrent M. genitalium-positive NGU, the authors monitored longitudinal changes in M. genitalium load from the beginning of the treatment to the period of recurrence of NGU with a TaqMan assay to quantify copies of the M. genitalium 16S rRNA gene in their urine [23]. M. genitalium loads in men with M. genitaliumpositive NGU were suppressed to below the detection level of the TaqMan assay during levofloxacin therapy, and signs and symptoms of urethritis disappeared.…”