Failure to detect Mycoplasma fermentans, Mycoplasma penetrans, or Mycoplasma pirum in the urethra of patients with acute nongonococcal urethritis

High Prevalence of Mycoplasma penetrans in Chlamydia trachomatis Positive Rectal Samples From Men: A Brief Report

Mycoplasma penetrans has gained increased attention in relation to sexually transmitted infections, however, its pathogenic potential and prevalence in different populations remains to be elucidated. Among 293 Chlamydia trachomatis positive rectal samples submitted for lymphogranuloma venereum typing, M. penetrans was detected by PCR in 13.4% of 231 male samples.

The bacterial microbiota in first-void urine from men with and without idiopathic urethritis

Background

Non-gonococcal urethritis (NGU) is a common syndrome in men. NGU may have several causes, but many cases are caused by sexually transmitted infections that may also cause complications in their female partners. Chlamydia trachomatis and Mycoplasma genitalium are the most common causes of NGU, but in up to 35% of the cases, none of the known viral or bacterial causes are found. Traditionally, pathogens have been detected using various culture techniques that may not identify all species present in the urethra. To address this, we used culture-independent methods for analysis of the male urethral microbiota.

Methods

This case-control study analysed first void urine samples, collected at STD clinics in Stockholm, Sweden from men with idiopathic urethritis (IU), i.e. negative for Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Ureaplasma urealyticum, Trichomonas vaginalis, adenovirus, and herpes simplex virus type 1 and -2 together with samples from men without urethritis. Forty-six controls and 39 idiopathic urethritis patients were analysed.

Results

The microbiota was highly diverse: None of the 302 operational taxonomic units (OTUs) found in negative controls and IU patients were found in all of the samples or even in all of the samples in one group. More than 50% of the OTUs were only found in one or two of the total of 85 samples. Still the most dominant 1/6 of the genera constituted 79% of the sequences.

Hierarchical clustering in a heatmap showed no specific clustering of patients or controls.

A number of IU patient samples were dominated by a single genus previously related to urethritis (Gardnerella, Haemophilus, Ureaplasma).

Conclusion

The male urethra contain a very diverse composition of bacteria, even in healthy controls. NGU may be caused by a number of different bacteria but more studies including a higher number of samples are needed for elucidation of the role of each species.

Mollicutes/HIV Coinfection and the Development of AIDS: Still Far from a Definitive Response

Background. Mycoplasmas are known to cause various infections in humans, mainly in the respiratory and urogenital tracts. The different species are usually host-specific and cause diseases in well-defined sites. New species have been isolated, including those from HIV-infected persons. Summary. Its in vitro properties, combined with clinical findings, have led to the hypothesis that these microorganisms may act as cofactors of HIV in AIDS development. Even today this point of view is quite polemic among infectious disease specialists and many aspects remain to be clarified, in contrast to what happens, for instance, with HIV/Mycobacterium tuberculosis coinfection. Dozens of papers have been published covering aspects of Mollicutes/HIV coinfection, but they add little to no information about the putative contribution of Mollicutes to the evolution of AIDS. Very few researchers have devoted their efforts to trying to answer this question, which remains open. In this review, we discuss the evidences that may support this statement in the light of current knowledge in the field of mycoplasmology.

Mycoplasmas and ureaplasmas as neonatal pathogens

The genital mycoplasmas represent a complex and unique group of microorganisms that have been associated with a wide array of infectious diseases in adults and infants. The lack of conclusive knowledge regarding the pathogenic potential of Mycoplasma and Ureaplasma spp. in many conditions is due to a general unfamiliarity of physicians and microbiology laboratories with their fastidious growth requirements, leading to difficulty in their detection; their high prevalence in healthy persons; the poor design of research studies attempting to base association with disease on the mere presence of the organisms in the lower urogenital tract; the failure to consider multifactorial aspects of diseases; and considering these genital mycoplasmas only as a last resort. The situation is now changing because of a greater appreciation of the genital mycoplasmas as perinatal pathogens and improvements in laboratory detection, particularly with regard to the development of powerful molecular nucleic acid amplification tests. This review summarizes the epidemiology of genital mycoplasmas as causes of neonatal infections and premature birth; evidence linking ureaplasmas with bronchopulmonary dysplasia; recent changes in the taxonomy of the genus Ureaplasma; the neonatal host response to mycoplasma and ureaplasma infections; advances in laboratory detection, including molecular methods; and therapeutic considerations for treatment of systemic diseases.

Detection of several Mycoplasma species at various anatomical sites of homosexual men

In order to determine the colonisation patterns of several Mycoplasma species in homosexual men, urethral, oral and rectal specimens from 10 homosexual men with acute non-gonococcal urethritis (NGU) and 18 without NGU were examined using sensitive methods. Mycoplasma hominis and Ureaplasma urealyticum existed in both groups, which is in keeping with previous studies of heterosexual men. Mycoplasma genitalium was detected in the rectum of both NGU-positive and NGU-negative men and in the urethra of one man with chlamydia-negative NGU, but not in those without urethritis. Mycoplasma fermentans was found in the throat and rectum only and Mycoplasma penetrans in all three anatomical sites. In contrast, Mycoplasma pirum was found in the rectum only, that is, in 5 of the 28 men studied. Infrequent examination of this site is a possible explanation for previous failures to detect Mycoplasma pirum at a mucosal surface.

Rapid detection of Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum organisms in genitourinary samples by PCR-microtiter plate hybridization assay

We present a method for detecting the presence of Mycoplasma genitalium, Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum organisms, which are thought to be associated with nongonococcal urethritis (NGU) and other genitourinary infections, in clinical samples. This method consists of PCR amplification of a part of the 16S rRNA gene followed by 96-well microtiter plate hybridization assay using four species-specific capture probes to detect the targets. To test the efficacy of this method, we applied it to the detection of the four species in the urine of patients with NGU. There were no cross-reactions with other human mycoplasmas or ureaplasmas, and the PCR-microtiter plate hybridization assay detected as few as 10 copies of the 16S rRNA gene of each of the four species. Based on these results, this PCR-microtiter plate hybridization assay can be considered an effective tool for the diagnosis of genitourinary infections with mycoplasmas or ureaplasmas.

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.

Detection of Mycoplasma fermentans in healthy students and patients with congenital immunodeficiency

OBJECTIVES

To determine the prevalence of M. fermentans at different anatomical sites in healthy subjects and in patients with congenital immunodeficiency, and to determine whether haematogenous invasion occurs among the latter.

METHODS

A polymerase chain reaction (PCR) assay was used to detect M.fermentans in throat swabs and urine specimens from healthy students, and from patients with congenital immunodeficiency. Peripheral blood mononuclear cells (PBMCs) from the latter group were also tested.

RESULTS

Sixty-two students provided throat swabs, of which 11 (18%) were M. Jermentans-positive; 46 provided urine specimens, of which eight (17%) were positive. Of the 45 students who provided both throat and urine specimens, 12 (27%) had M. fermentans-positive samples; four in the throat and urine, four in the throat only and four in the urine only. Nineteen of the 20 patients with congenital immunodeficiency provided throat swabs, of which one (5%) was M. fermentans-positive; 19 also provided urine specimens, of which three (16%) were positive. All of the immunodeficient patients provided a PBMC sample, but none was positive.

CONCLUSION

M. fermentans occurred frequently at mucosal sites in a healthy population and in subjects with congenital immunodeficiency. However, such a deficiency did not lead to overt haematogenous invasion.

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.

Detection of mycoplasmas in urethral swabs from HIV-1 infected patients and control individuals using culture techniques and polymerase chain reaction

The objective of the present study was to determine the prevalence of certain mycoplasma species, i.e., Mycoplasma hominis, Ureaplasma urealyticum and Mycoplasma penetrans, in urethral swabs from HIV-1 infected patients compared to swabs from a control group. Mycoplasmas were detected by routine culture techniques and by the Polymerase Chain Reaction (PCR) technique, using 16SrRNA generic primers of conserved region and Mycoplasma penetrans specific primers. The positivity rates obtained with the two methods were comparable. Nevertheless, PCR was more sensitive, while the culture techniques allowed the quantification of the isolates. The results showed no significant difference (p < 0.05) in positivity rates between the methods used for mycoplasma detection.

Mycoplasmas: sophisticated, reemerging, and burdened by their notoriety

Mycoplasmas are most unusual self-replicating bacteria, possessing very small genomes, lacking cell wall components, requiring cholesterol for membrane function and growth, using UGA codon for tryptophan, passing through "bacterial-retaining" filters, and displaying genetic economy that requires a strict dependence on the host for nutrients and refuge. In addition, many of the mycoplasmas pathogenic for humans and animals possess extraordinary specialized tip organelles that mediate their intimate interaction with eucaryotic cells. This host-adapted survival is achieved through surface parasitism of target cells, acquisition of essential biosynthetic precursors, and in some cases, subsequent entry and survival intracellularly. Misconceptions concerning the role of mycoplasmas in disease pathogenesis can be directly attributed to their biological subtleties and to fundamental deficits in understanding their virulence capabilities. In this review, we highlight the biology and pathogenesis of these procaryotes and provide new evidence that may lead to increased appreciation of their role as human pathogens.

Mycoplasma fermentans, but not M penetrans, detected by PCR assays in synovium from patients with rheumatoid arthritis and other rheumatic disorders

AIM/BACKGROUND

Mycoplasmas, especially Mycoplasma fermentans, were suggested more than 20 years ago as a possible cause of rheumatoid arthritis but this hypothesis was never substantiated. In view of the superior sensitivity of the polymerase chain reaction (PCR) assay over culture, the aim was to use this method to seek M fermentans and M penetrans in synovial samples from patients with various arthritides.

METHODS

Synovial fluid samples (n = 154) and synovial biopsy specimens (n = 20) from 133 patients with various rheumatic disorders were stored at -80 degrees C for between one and 40 months. Aliquots (500 microliters) of the synovial fluid samples were centrifuged and the deposit, and also the synovial biopsy specimens (approximately 1 g) were placed in lysis buffer with proteinase K for DNA extraction. The DNA was tested by using a semi-nested PCR assay for M fermentans and a single-round PCR for M penetrans.

RESULTS

M fermentans was detected in the joints of eight (21%) of 38 patients with rheumatoid arthritis, two (20%) of 10 patients with spondyloarthropathy with peripheral arthritis, one (20%) of five patients with psoriatic arthritis, and four (13%) of 31 patients with unclassified arthritis. M fermentans was not found in the joints of the seven patients with reactive arthritis, the 29 with osteoarthritis or post-traumatic hydrarthrosis, the nine with gouty arthritis, nor the four with chronic juvenile arthritis. M penetrans was not detected in any sample.

CONCLUSIONS

These findings show that the presence of M fermentans in the joint is associated with inflammatory rheumatic disorders of unknown cause, including rheumatoid arthritis. However, whether this organism triggers or perpetuates disease of behaves as a passenger remains conjectural.