Mycoplasma genitalium attaches to human spermatozoa.
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BACKGROUND: Mycoplasma genitalium causes urogenital diseases in men and women and is presumed to be sexually transmitted. We wanted to investigate whether spermatozoa could serve as vectors for M.genitalium in order to cause upper genital diseases in women. METHODS: By use of Nomarski light microscopy and transmission X-ray microscopy, the attachment of M.genitalium to spermatozoa was studied. Semen was incubated in vitro with M.genitalium. Purified, motile spermatozoa were examined for attachment of M.genitalium by immunofluorescence microscopy. RESULTS: Mycoplasma genitalium was shown to adhere to the head, midpiece and tail of the spermatozoa. The spermatozoa became immotile when many M.genitalium were attached. However, the motile spermatozoa were demonstrated to carry M.genitalium and in this case the mycoplasmas were seen to attach mostly to the midpiece or neck region. Occasionally, M.genitalium was seen at the head but not at the tail. By X-ray microscopy, it was possible to observe the diffentiated structure of M.genitalium, and the attachment seemed to be mediated by the tip. CONCLUSIONS: Mycoplasma genitalium can bind to human spermatozoa and thus could be carried by motile sperm. This ability may be important in the process of causing female genital diseases and infertility. (+info)
Gene essentiality determines chromosome organisation in bacteria.
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In Escherichia coli and Bacillus subtilis, essentiality, not expressivity, drives the distribution of genes between the two replicating strands. Although essential genes tend to be coded in the leading replicating strand, the underlying selective constraints and the evolutionary extent of these findings have still not been subject to comparative studies. Here, we extend our previous analysis to the genomes of low G + C firmicutes and gamma-proteobacteria, and in a second step to all sequenced bacterial genomes. The inference of essentiality by homology allows us to show that essential genes are much more frequent in the leading strand than other genes, even when compared with non- essential highly expressed genes. Smaller biases were found in the genomes of obligatory intracellular bacteria, for which the assignment of essentiality by homology from fast growing free-living bacteria is most problematic. Cross-comparisons used to assess potential errors in the assignment of essentiality by homology revealed that, in most cases, variations in the assignment criteria have little influence on the overall results. Essential genes tend to be more conserved in the leading strand than average genes, which is consistent with selection for this positioning and may impose a strong constraint on chromosomal rearrangements. These results indicate that essentiality plays a fundamental role in the distribution of genes in most bacterial genomes. (+info)
Diagnostic assessment of Mycoplasma genitalium in culture-positive women.
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Detection of Mycoplasma genitalium-mediated, chlamydia-negative nongonococcal urethritis and other M. genitalium-linked infectious etiologies has been very challenging. Although M. genitalium is considered a leading cause of genitourinary symptoms in men and women, extreme difficulties in its cultivation due to its highly fastidious nature and the lack of routine and effective diagnostic tests have slowed the generation of clinical data which directly implicate the presence of M. genitalium in disease pathogenesis. In this study, we compared enzyme-linked immunosorbent assays (ELISAs) and immunoblot and PCR assays in M. genitalium culture-positive women over 1 to 3 years of clinical visits to determine the usefulness of independent diagnostic strategies. Furthermore, the value of combinatorial diagnostic assessments is described, which provides insights into the dynamics of M. genitalium-host interactions. Overall, we show that neither ELISA nor PCR, alone or in combination, provides the sensitivity required to confidently predict the existence of viable M. genitalium organisms in cervical and vaginal samples. Additionally, culture-positive women exhibited a range of antibody responsiveness to M. genitalium based upon ELISA and immunoblot assessments, indicating immune diversity among this high-risk population. (+info)
Use of TaqMan 5' nuclease real-time PCR for quantitative detection of Mycoplasma genitalium DNA in males with and without urethritis who were attendees at a sexually transmitted disease clinic.
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Mycoplasma genitalium is a cause of nongonococcal urethritis, particularly in patients not infected with Chlamydia trachomatis. A quantitative 5' nuclease assay (TaqMan PCR) was developed and validated. The assay detected a fragment of the MgPa adhesin gene by use of a TaqMan MGB (minor groove binder) probe and included an internal processing control to detect PCR inhibition. Urethral swab specimens and first-void urine samples from M. genitalium-positive men were examined, and the M. genitalium DNA load was correlated to symptoms and signs. The assay consistently detected <5 genome copies without cross-reactions with other mycoplasmas. Urine and urethral swab specimens from men with urethritis had higher M. genitalium DNA loads than specimens from men without urethritis. However, a very broad overlap of DNA loads between patients with and without urethritis was observed. Urethral swab specimens from patients with urethral discharge had a significantly higher DNA load than specimens from patients without discharge. This correlation was not found in first-void urine specimens. (+info)
Determination of infectious load of Mycoplasma genitalium in clinical samples of human vaginal cells.
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Mycoplasma genitalium is a leading cause of chlamydia-negative, nongonoccocal urethritis and has been directly implicated in numerous other genitourinary as well as extragenitourinary tract pathologies. Detection of M. genitalium has relied almost entirely on PCR amplification of clinical specimens and evidence of seroconversion since these mycoplasmas are highly fastidious and culture isolation by microbiological techniques is very rare. We have established a combinatorial strategy using confocal immunoanalysis (CIA) and real-time PCR to qualitatively and quantitatively assess patterns of M. genitalium infection in women attending a sexually transmitted disease-related health clinic in San Antonio, Tex. CIA allows spatial examination of mycoplasmas on surfaces and inside human target cells, plus the ability to evaluate cell-to-cell patterns and variances within samples. Real-time PCR permits determination of genome copy numbers of mycoplasmas and human cells by multiplex amplification using mycoplasma gyrA and human RNase P gene sequences, which indicates overall levels of mycoplasma infection and degree of parasitism. These assays are strongly correlated and, in combination, permit detection and elucidation of heretofore-unrecognized patterns of M. genitalium infections in clinical and experimental samples. (+info)
GeneOrder3.0: software for comparing the order of genes in pairs of small bacterial genomes.
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BACKGROUND: An increasing number of whole viral and bacterial genomes are being sequenced and deposited in public databases. In parallel to the mounting interest in whole genomes, the number of whole genome analyses software tools is also increasing. GeneOrder was originally developed to provide an analysis of genes between two genomes, allowing visualization of gene order and synteny comparisons of any small genomes. It was originally developed for comparing virus, mitochondrion and chloroplast genomes. This is now extended to small bacterial genomes of sizes less than 2 Mb. RESULTS: GeneOrder3.0 has been developed and validated successfully on several small bacterial genomes (ca. 580 kb to 1.83 Mb) archived in the NCBI GenBank database. It is an updated web-based "on-the-fly" computational tool allowing gene order and synteny comparisons of any two small bacterial genomes. Analyses of several bacterial genomes show that a large amount of gene and genome re-arrangement occurs, as seen with earlier DNA software tools. This can be displayed at the protein level using GeneOrder3.0. Whole genome alignments of genes are presented in both a table and a dot plot. This allows the detection of evolutionary more distant relationships since protein sequences are more conserved than DNA sequences. CONCLUSIONS: GeneOrder3.0 allows researchers to perform comparative analysis of gene order and synteny in genomes of sizes up to 2 Mb "on-the-fly." AVAILABILITY: http://binf.gmu.edu/genometools.html and http://pasteur.atcc.org:8050/GeneOrder3.0. (+info)
Symptomatic urethritis is more prevalent in men infected with Mycoplasma genitalium than with Chlamydia trachomatis.
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OBJECTIVES: To study the prevalence, symptoms, and signs of Mycoplasma genitalium and Chlamydia trachomatis infections in men attending a Swedish STD clinic and to study the criteria for urethritis. METHODS: A cross sectional study among STD clinic attendees in Orebro, Sweden. Attendees were examined for microscopic urethritis and first void urine (FVU) was tested for M genitalium and C trachomatis. RESULTS: The prevalence of M genitalium and C trachomatis was 7% (34/512) and 12% (61/512), respectively. Dual infection was diagnosed in four men. In both infections 90% of the patients had signs of microscopic urethritis. M genitalium positive men had symptomatic urethritis significantly more often than those infected with C trachomatis (73% v 40%, RR 1.8; 95% CI 1.2 to 2.7). 63% of female partners of men infected with M genitalium were infected with M genitalium compared with chlamydial infection in 67% of female partners of men infected with C trachomatis. Non-chlamydial non-gonococcal urethritis without evidence of M genitalium infection was diagnosed in 180 men (35%). Symptoms and/or visible discharge were reported in 49% in this group. CONCLUSIONS: M genitalium is a common infection associated with symptomatic urethritis and with a high prevalence of infected sexual partners supporting its role as a sexually transmitted infection. (+info)
High prevalence of genital mycoplasmas among sexually active young adults with urethritis or cervicitis symptoms in La Crosse, Wisconsin.
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Sexually active young adults in the small college town of La Crosse, Wisconsin, were evaluated for conventional sexually transmitted pathogens and tested for infections with mycoplasmas. The prevalence in 65 symptomatic men or women and 137 healthy volunteers (67 men and 70 women) was compared. Urine specimens from both cohorts were tested by ligase chain reaction for Chlamydia trachomatis or Neisseria gonorrhoeae. In addition, the urethral or cervical swabs from the symptomatic subjects were tested by PCR for Mycoplasma genitalium and cultured for Mycoplasma hominis and the ureaplasmas. The results confirmed a relatively low prevalence of gonorrhea among symptomatic men (12%) and chlamydia among symptomatic men (15%) and normal women (3%). In contrast, infections with mycoplasmas, especially the ureaplasmas (57%), were common and the organisms were the only potential sexually transmitted pathogen detected in 40 (62%) symptomatic subjects. Because of the high prevalence, we also evaluated urethral swabs from an additional 25 normal female volunteers and recovered ureaplasmas from 4 (16%) subjects. Additionally, the participants rarely used protection during sexual intercourse and some symptomatic subjects apparently acquired their infections despite using condoms regularly. The findings demonstrate a strong association between abnormal urogenital findings and detection of myoplasmas, particularly ureaplasmas, and suggest the infections will remain common. (+info)