Prevalence of Mycoplasma genitalium in men with gonococcal urethritis

Mycoplasma genitalium: An emergent sexually transmitted disease?

This article summarizes the epidemiologic evidence linking Mycoplasma genitalium to sexually transmitted disease syndromes, including male urethritis, and female cervicitis, pelvic inflammatory disease, infertility, and adverse birth outcomes. It discusses the relationship of this bacterium to human immunodeficiency virus infection and reviews the available literature on the efficacy of standard antimicrobial therapies against M genitalium.

The Role of Mycoplasma genitalium and Ureaplasma urealyticum Biovar 2 in Postgonococcal Urethritis

BACKGROUND

There are few studies on coinfection with genital mycoplasmas and ureaplasmas in men with gonococcal urethritis (GU). The role of these species in postgonococcal urethritis (PGU) is poorly understood. Thus, we conducted a study to determine the prevalence of coinfection with genital mycoplasmas and ureaplasmas among men with GU and to assess the role of these pathogens in PGU.

METHODS

Three hundred ninety men infected with culture-confirmed Neisseria gonorrhoeae participated in the study. Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum biovar 1, and Ureaplasma urealyticum biovar 2 in first-voided urine samples were detected by polymerase chain reaction-based assay at the patients' initial visits. PGU was judged to be present if the urethral smear was positive for polymorphonuclear leucocytes 7-14 days after treatment for gonorrhea. The association between each microorganism and PGU, measured by the odds ratio, was estimated by multivariate logistic regression analysis.

RESULTS

C. trachomatis, M. genitalium, M. hominis, U. parvum biovar 1, and U. urealyticum biovar 2 were detected in 85 (21.8%), 16 (4.1%), 8 (2.1%), and 33 men (8.5%), respectively. In patients with chlamydia-negative GU, coinfection with M. genitalium was associated with a 14.54-fold greater risk of PGU (95% confidence interval, 2.91-72.74), and coinfection with U. urealyticum biovar 2 was associated with a 3.64-fold greater risk of PGU (95% confidence interval, 1.24-10.63).

CONCLUSIONS

Coinfection with M. genitalium or U. ureaplasma biovar 2 in men with GU was significantly associated with PGU, independent of C. trachomatis. Men with GU should be treated presumptively with antibiotics that are active against C. trachomatis, M. genitalium, and U. urealyticum biovar 2.

Mycoplasma genitalium urethritis in men

Mycoplasma genitalium was first isolated from two men with non-gonococcal urethritis (NGU) and thereafter shown to produce urethritis in subhuman primates, inoculated intraurethrally. This mycoplasma has been detected significantly more often in patients with acute NGU, particularly in patients with non-chlamydial NGU, than in subjects without urethritis. The prevalence of M. genitalium-positive non-chlamydial NGU ranges from 18 to 46% of all non-chlamydial NGU cases. In addition, the persistence of M. genitalium in the urethra after antimicrobial chemotherapy is associated with persistence or recurrence of NGU. The various results reported to date tend to support the proposition that M. genitalium is a pathogen of NGU. M. genitalium is highly susceptible to tetracyclines, macrolides, and some new fluoroquinolones, but the clinical data on the chemotherapy in M. genitalium-positive NGU is extremely limited. Because of the possible association between the post-treatment presence of M. genitalium in the urethra and persistent or recurrent NGU, the eradication of this mycoplasma from the urethra is essential in the management of patients with M. genitalium-positive NGU. Further studies are required to establish the optimal chemotherapy for M. genitalium-positive NGU.

Detection and quantification of Mycoplasma genitalium in male patients with urethritis

Detection and quantification of Mycoplasma genitalium were evaluated in 83 patients with urethritis (group 1), 60 patients with urethral symptoms but no urethritis (group 2), and 50 asymptomatic men (group 3). Quantification of M. genitalium was carried out using real-time polymerase chain reaction (PCR) analysis of first-pass urine samples. The rate of detection of M. genitalium was significantly higher in group 1 than in groups 2 and 3 (P<.0001). The mean observed concentration of M. genitalium was 1.2x10(4) equivalent genomes/mL of urine (range, 50 to 8x10(4) equivalent genomes/mL). Analysis of M. genitalium load in serial urine samples collected before and after the administration of antibacterial treatment showed an association between clinical and microbiological responses, with a shift to negative PCR results in symptom-free patients. Our results illustrate the usefulness of monitoring the M. genitalium load in evaluating the susceptibility of M. genitalium to antibacterial treatment.

High prevalence of Mycoplasma genitalium in the lower genitourinary tract of women attending a sexually transmitted disease clinic in Paris, France

BACKGROUND

Previous studies have suggested that Mycoplasma genitalium is associated with cervicitis and may be a cause of pelvic inflammatory disease. This study attempted to investigate further the possible role of M genitalium in genital symptoms of women attending a sexually transmitted disease (STD) clinic.

GOAL

To determine the prevalence of and the association of clinical and microbiologic features with M genitalium in women presenting with genital symptoms.

STUDY DESIGN

Between April 1994 and June 1996 a prospective study of 170 consecutive women with abnormal vaginal discharge, with or without urethral itching, dysuria, or pelvic pain, was conducted at the STD clinic at Saint-Louis Hospital in Paris. Information was collected on each subject's characteristics, and a clinical vulvar, vaginal, and cervical examination was performed. Cervical, vaginal, and urethral samples were obtained to identify infecting organisms.

RESULTS

DNA of M genitalium was identified by polymerase chain reaction (PCR) at one or more genital sites in 65 women (38%; 95% CI, 31-46%) and was statistically more frequently detected in the vagina (39%) than in the cervix (21%) or urethra (28%) (P = 0.001 and 0.048, respectively). PCR inhibitors were detected in 17 specimens (4%). M genitalium was found in 6/14 (43%) positive for Chlamydia trachomatis, but no significant association between M genitalium and any demographic, clinical, or microbiologic data was noted in univariable or multivariable analysis.

CONCLUSION

This study indicates that M genitalium is frequently encountered in the female genital tract and is not associated with cervicitis or any particular clinical or microbiologic data.

Quantitative detection of Mycoplasma genitalium from first-pass urine of men with urethritis and asymptomatic men by real-time PCR

We developed a TaqMan-based real-time PCR assay for quantifying Mycoplasma genitalium. This assay is able to specifically quantify concentrations of the M. genitalium 16S rRNA gene ranging from 10(7) to 10 copies/reaction. Using the TaqMan assay, we quantified the M. genitalium 16S rRNA gene in first-pass urine of men with urethritis and asymptomatic men who were positive for M. genitalium by PCR- and phylogeny-based assay. Of 130 men with gonococcal urethritis (GU), five were positive for M. genitalium. The mycoplasma load for each specimen was <5 x 10 copies/ml. Of 84 men with chlamydial non-GU (CNGU), seven were positive for M. genitalium. One man had an M. genitalium load of <5 x 10 copies/ml, and six men had loads ranging from 1.1 x 10(7) to 2.7 x 10(2) copies/ml. Of 86 men with nonchlamydial NGU (NCNGU), 17 were positive for M. genitalium. The mycoplasma loads for these men ranged from 3.3 x 10(6) to 2.3 x 10(2) copies/ml. Of 76 asymptomatic men, only two were positive for M. genitalium. For these men, the loads were 2 x 10(2) and <5 x 10 copies/ml. The patients with NGU had significantly higher concentrations of M. genitalium in their first-pass urine than did men with GU (P < 0.01) or asymptomatic men (P < 0.05). In addition, M. genitalium loads were significantly higher in men with NCNGU than those in asymptomatic men (P < 0.05). The quantitative assessment of M. genitalium loads by the TaqMan assay will provide useful information for understanding the pathogenicity of this mycoplasma in the urogenital tract.

Mycoplasma genitalium: another important pathogen of nongonococcal urethritis

PURPOSE

We reviewed findings on the pathogenic role of Mycoplasma genitalium in nongonococcal urethritis and the treatment of men with M. genitalium positive nongonococcal urethritis.

MATERIALS AND METHODS

We reviewed literature selected from peer reviewed journals listed in MEDLINE and from resources cited in those articles from 1967 to January 2001.

RESULTS

M. genitalium was first isolated from 2 men with nongonococcal urethritis and thereafter it was shown to cause urethritis in subhuman primates inoculated intraurethrally. This mycoplasma has been detected significantly more often in patients with acute nongonococcal urethritis, particularly in those with nonchlamydial nongonococcal urethritis, than in those without urethritis. The prevalence of M. genitalium positive nonchlamydial nongonococcal urethritis is 18.4% to 45.5% of all nonchlamydial nongonococcal urethritis cases. In addition, the persistence of M. genitalium in the urethra after antimicrobial chemotherapy is associated with persistent or recurrent nongonococcal urethritis. M. genitalium is highly susceptible to tetracycline, macrolide and some new fluoroquinolones. The regimen of 100 mg. doxycycline orally twice daily for 7 days, which is recommended for chlamydial nongonococcal urethritis, seems to be effective for M. genitalium positive nongonococcal urethritis, although clinical data to substantiate this regimen are limited.

CONCLUSIONS

The various results reported to date tend to support the proposition that M. genitalium is a pathogen of nongonococcal urethritis. However, currently diagnostic methods for this important mycoplasma are not available in clinical practice. Because of the possible association of the posttreatment presence of M. genitalium in the urethra with persistent or recurrent nongonococcal urethritis, eradication of this mycoplasma from the urethra is essential for managing M. genitalium positive disease. However, clinical data on treating M. genitalium positive nongonococcal urethritis are extremely limited. Thus, further studies are required to develop new diagnostic methods that would be available in clinical settings and establish a new treatment algorithm for nongonococcal urethritis, including M. genitalium positive disease.

Increased frequency of detection of Ureaplasma urealyticum and Mycoplasma genitalium in AIDS patients without urethral symptoms

The roles of Mycoplasma genitalium and Ureaplasma urealyticum in nongonococcal urethritis are not yet well established. The aim of this study was to determine the presence of these microorganisms in the urethral tracts of 187 human immunodeficiency virus type 1 (HIV-1)-infected male patients with no clinical signs of urethritis. The results indicate that the prevalence of M. genitalium and U. urealyticum was higher in AIDS patients than in asymptomatic, HIV-1-infected patients and in healthy individuals. The high rate of mycoplasmas and ureaplasmas detected in AIDS patients, in the absence of urethritis, argues against major roles in causing disease at the urethral mucosal level for these microorganisms.

Detection of Mycoplasma genitalium in patients with urethritis

PURPOSE

We attempted to detect Mycoplasma genitalium in urethral swab specimens by a polymerase chain reaction based assay to determine the prevalence of M. genitalium in patients with urethritis.

MATERIALS AND METHODS

We examined a total of 171 Japanese men who presented to our hospital from February 1995 through January 1997. Of these men 150 had symptoms and signs compatible with acute urethritis and 21 had no symptoms or signs of urethritis. Urethral swab specimens were used to culture Neisseria gonorrhoeae, to detect Chlamydia trachomatis by an enzyme immunoassay and to detect M. genitalium by a polymerase chain reaction based assay.

RESULTS

Gonococcal urethritis was diagnosed in 74 symptomatic men, and nongonococcal urethritis was diagnosed in 76 symptomatic men. Of the 74 cases of gonococcal urethritis 3 (4.1%) were positive for M. genitalium, and 14 (18.9%) were positive for C. trachomatis. Of the 76 cases of nongonococcal urethritis 10 (13.2%) were positive for M. genitalium, and 42 (55.2%) were positive for C. trachomatis. While only 1 of the 42 cases with chlamydial nongonococcal urethritis (2.4%) was positive for M. genitalium, 9 of the 34 chlamydia negative nongonococcal urethritis cases (26.5%) were positive for the mycoplasma. In contrast, all 21 cases men were negative for N. gonorrhoeae, M. genitalium, and C. trachomatis.

CONCLUSIONS

The prevalences of M. genitalium in patients with gonococcal urethritis and nongonococcal urethritis who attended our clinic were 4.1 and 13.2%, respectively. M. genitalium was detected significantly more often in men with nongonococcal urethritis than in asymptomatic men. In addition, its prevalence in men with chlamydia negative nongonococcal urethritis (26.5%) was significantly greater than in those with chlamydia positive nongonococcal urethritis (2.4%). These findings suggest that M. genitalium may be associated with the development of nongonococcal urethritis independent of C. trachomatis.