Impact of 16S rRNA Single Nucleotide Polymorphisms on Mycoplasma genitalium Organism Load with Doxycycline Treatment.

Doxycycline targets the 16S rRNA and is widely used for the treatment of sexually transmitted infections. While it is not highly effective at eradicating Mycoplasma genitalium infections, it can reduce organism load. The aim of this study was to investigate the association between single nucleotide polymorphisms (SNPs) in the 16S rRNA gene of M. genitalium and change in organism load. M. genitalium samples were collected from 56 men prior to commencing doxycycline and at a median of 13 of 14 doses. These were sequenced for the 16S rRNA, and the association between 16S rRNA SNPs and change in organism load was determined. 16S rRNA sequences were available for 52/56 (92.9%) M. genitalium-infected men, of which 20 (38.5%) had an undetectable load, 26 (50.0%) had a decrease in M. genitalium load (median change of 105-fold), and 6 (11.5%) had an increase in load (median change of 5-fold). The most common SNPs identified were A742G (10/52 [19.2%]), GG960-961TT/C (7/52 [13.5%]), and C1435T (28/52 [53.8%]) (M. genitalium numbering). None were associated with a change in organism load (P = 0.76, 0.16, and 0.98, respectively). Using pooled published data from 28 isolates, no clear relationship between the SNPs and doxycycline MIC was identified. In conclusion, the low efficacy of doxycycline against M. genitalium does not appear to be due to variation in the 16S rRNA gene.

Adverse pregnancy and neonatal outcomes associated with Neisseria gonorrhoeae, Mycoplasma genitalium, M. hominis, Ureaplasma urealyticum and U. parvum: a systematic review and meta-analysis protocol.

INTRODUCTION: Several bacterial sexually transmitted and genital mycoplasma infections during pregnancy have been associated with poor pregnancy and perinatal outcomes. Comprehensive and systematic information about associations between sexually transmitted infections (STI) and genital infections in pregnancy and adverse perinatal outcomes is needed to improve understanding about the evidence for causal associations between these infections and adverse pregnancy and neonatal outcomes. Our primary objective is to systematically review the literature about associations between: (1) Neisseria gonorrhoeae in pregnancy and preterm birth; (2) Mycoplasma genitalium in pregnancy and preterm birth; (3) M. hominis, Ureaplasma urealyticum and/or U. parvum in pregnancy and preterm birth. METHODS AND ANALYSIS: We will undertake a systematic search of Medline, Excerpta Medica database and the Cochrane Library and Cumulative Index to Nursing and Allied Health Literature. Following an initial screening of titles by one reviewer, abstracts will be independently assessed by two reviewers before screening of full-text articles. To exclude a manuscript, both reviewers need to agree on the decision. Any discrepancies will be resolved by discussion, or the adjudication of a third reviewer. Studies will be included if they report testing for one or more of N. gonorrhoeae, M. genitalium, M. hominis, U. urealyticum and/or U. parvum during pregnancy and report pregnancy and/or birth outcomes. In this review, the primary outcome is preterm birth. Secondary outcomes are premature rupture of membranes, low birth weight, spontaneous abortion, stillbirth, neonatal mortality and ophthalmia neonatorum. We will use standard definitions, or definitions reported by study authors. We will examine associations between exposure and outcome in forest plots, using the I2 statistic to examine between study heterogeneity. Where appropriate, we will use meta-analysis to combine results of individual studies. ETHICS AND DISSEMINATION: This systematic review of published literature does not require ethical committee approval. Results of this review will be published in a peer reviewed, open access journal. PROSPERO REGISTRATION NUMBER: CRD42016050962.

In vitro activity of zoliflodacin (ETX0914) against macrolide-resistant, fluoroquinolone-resistant and antimicrobial-susceptible Mycoplasma genitalium strains.

Background: Mycoplasma genitalium is estimated to be the second most common cause of bacterial sexually transmitted infection in Europe. It is of increasing public health concern due to the rapid development of resistance to different antimicrobial classes, including the preferred first- and second-line treatments azithromycin and moxifloxacin. Thus, new antimicrobial agents are urgently needed, especially for the treatment of MDR strains. Methods: The in vitro activity of the new spiropyrimidinetrione zoliflodacin against 47 M. genitalium strains was assessed by growing M. genitalium in Vero cell culture and measuring growth by quantitative PCR. The collection included 34 moxifloxacin-susceptible (MIC <1 mg/L) and 13 moxifloxacin-resistant (MIC ≥1 mg/L) strains. Twenty-three of the strains were azithromycin resistant (MIC ≥16 mg/L) and 12 of these strains were MDR. Results: Only one (2.1%) strain with substantially increased MIC (4 mg/L) and potential resistance to zoliflodacin was found. Zoliflodacin was overall more potent than moxifloxacin (P = 0.009) and no cross-resistance was observed between the two drug classes of topoisomerase II inhibitors. Differences in the MICs of zoliflodacin and azithromycin were not statistically significant; however, 23 (48.9%) compared with potentially 1 (2.1%) of the strains were resistant to azithromycin and zoliflodacin, respectively. Conclusions: Zoliflodacin is a promising candidate for the treatment of M. genitalium and it is important to further develop and evaluate this drug.

Prediction of the persistence of Mycoplasma genitalium after antimicrobial chemotherapy by quantification of leukocytes in first-void urine from patients with non-gonococcal urethritis.

Mycoplasma genitalium is regarded as another pathogen of male non-gonococcal urethritis (NGU). Failure to eradicate this mycoplasma is associated with persistent or recurrent NGU, but this mycoplasma is not routinely examined in clinical practice. In cases of M. genitalium-positive NGU, therefore, some criteria are needed to assess the success or failure of antimicrobial chemotherapy other than microbiological outcomes. We enrolled 49 men with M. genitalium-positive non-chlamydial NGU. At successive visits after treatment, we inquired about their symptoms, observed their urethral meatus for urethral discharge, and examined their first-void urine (FVU) for quantification of leukocytes and for the persistence of M. genitalium. M. genitalium was eradicated in 34 patients after treatment, whereas the mycoplasma persisted in 15. Urethritis symptoms and urethral discharges were not found to be predictors of the persistence of M. genitalium up to the 25th day after the start of treatment. Leukocyte counts in FVU from the patients with persistence of M. genitalium were significantly higher than those from the patients with eradication of the mycoplasma. Leukocyte counts of 10 leukocytes/µl or more between the 18th and 24th day after the start of treatment were most significantly associated with the persistence of M. genitalium. Quantification of leukocytes in FVU would appear to be crucial to judge the outcome of treatment in patients with non-chlamydial NGU and could be helpful to predict the persistence of M. genitalium after treatment when M. genitalium is not routinely examined in clinical specimens in clinical practice.

[Generalized mycoplasma infection in patients and carriers].

AIM: Study of possibility of generalization of mycoplasma infection in patients with urogenital pathology. MATERIALS AND METHODS: Among the examined patients 5 males characterized by risky sexual behavior with pronounced symptoms of infection or without those were selected. Patients were examined by a complex of methods for the presence of mycoplasma infection by culture, PCR, DFA, PHA, AHR and by detection of specific immune complexes in blood sera. Scrapes from urogenital tract, blood sera samples, urine, saliva, prostatic fluid were materials for the study. RESULTS: In blood of all patients in ELISA antibodies against Mycoplasma hominis were detected; in PHA they were detected only in 2 individuals. In all the patients in blood CIC were detected including antigens and DNA of one or several mycoplasma species. Sperm of 3 individuals was infected by Ureaplasma spp., 2--M. genitalium. In saliva of 2 individuals M. hominis was detected, 3--U. urealyticum. CONCLUSION: In all the examined patients the infection was shown to have generalized character. This phenomenon presents itself as quite significant because mycoplasma may cause anti-apoptotic and oncogenic effect.

WholeCellKB: model organism databases for comprehensive whole-cell models.

Whole-cell models promise to greatly facilitate the analysis of complex biological behaviors. Whole-cell model development requires comprehensive model organism databases. WholeCellKB (http://wholecellkb.stanford.edu) is an open-source web-based software program for constructing model organism databases. WholeCellKB provides an extensive and fully customizable data model that fully describes individual species including the structure and function of each gene, protein, reaction and pathway. We used WholeCellKB to create WholeCellKB-MG, a comprehensive database of the Gram-positive bacterium Mycoplasma genitalium using over 900 sources. WholeCellKB-MG is extensively cross-referenced to existing resources including BioCyc, KEGG and UniProt. WholeCellKB-MG is freely accessible through a web-based user interface as well as through a RESTful web service.

Cell division in a minimal bacterium in the absence of ftsZ.

Mycoplasma genomes exhibit an impressively low amount of genes involved in cell division and some species even lack the ftsZ gene, which is found widespread in the microbial world and is considered essential for cell division by binary fission. We constructed a Mycoplasma genitalium ftsZ null mutant by gene replacement to investigate the role of this gene and the presence of alternative cell division mechanisms in this minimal bacterium. Our results demonstrate that ftsZ is non-essential for cell growth and reveal that, in the absence of the FtsZ protein, M. genitalium can manage feasible cell divisions and cytokinesis using the force generated by its motile machinery. This is an alternative mechanism, completely independent of the FtsZ protein, to perform cell division by binary fission in a microorganism. We also propose that the mycoplasma cytoskeleton, a complex network of proteins involved in many aspects of the biology of these microorganisms, may have taken over the function of many genes involved in cell division, allowing their loss in the regressive evolution of the streamlined mycoplasma genomes.

Monitoring of Mycoplasma genitalium growth and evaluation of antibacterial activity of antibiotics tetracycline and levofloxacin using a wireless magnetoelastic sensor.

Mycoplasma genitalium (Mg) is the smallest and simplest self-replicating bacteria lacking of cell wall and is a human pathogen causing various diseases. This paper describes the real-time, long-term and in situ monitoring of the growth of Mg and evaluation of the effect of the antibiotics tetracycline and levofloxacin on the growth using a wireless magnetoelastic sensor. The sensor is fabricated by coating a magnetoelastic strip with a polyurethane protecting film. In response to a time-varying magnetic field, the sensor longitudinally vibrates at a resonance frequency, emitting magnetic flux that can be remotely detected by a pick-up coil. No physical connections between the sensor and the detection system are required. The wireless property facilitates aseptic operation. The adhesion of Mg on the sensor surface results in a decrease in the resonance frequency, which is proportional to the concentration of Mg. The shift of the resonance frequency-time curves shows that under routine culture condition the growth curve of Mg is composed of three phases those are lag, logarithmic and stationary phase, respectively. In the presence of the antibiotics, the lag phase in the growth inhibition curves is prolonged obviously and the stationary phase is substituted by a decline phase. The growth inhibition of Mg is related to the concentration of the antibiotics. The MIC50 (minimal inhibitory concentration) of Mg incubated in the presence of the antibiotics for 120h is calculated to be 1.5 and 0.5 microg/mL for tetracycline and levofloxacin, respectively.

Interaction of Mycoplasma genitalium with host cells: evidence for nuclear localization.

Mycoplasma genitalium (Mg) is a mollicute that causes a range of human urogenital infections. A hallmark of these bacteria is their ability to establish chronic infections that can persist despite completion of appropriate antibiotic therapies and intact and functional immune systems. Intimate adherence and surface colonization of mycoplasmas to host cells are important pathogenic features. However, their facultative intracellular nature is poorly understood, partly due to difficulties in developing and standardizing cellular interaction model systems. Here, we characterize growth and invasion properties of two Mg strains (G37 and 1019V). Mg G37 is a high-passage laboratory strain, while Mg 1019V is a low-passage isolate recovered from the cervix. The two strains diverge partially in gene sequences for adherence-related proteins and exhibit subtle variations in their axenic growth. However, with both strains and consistent with our previous studies, a subset of adherent Mg organisms invade host cells and exhibit perinuclear targeting. Remarkably, intranuclear localization of Mg proteins is observed, which occurred as early as 30 min after infection. Mg strains deficient in adherence were markedly reduced in their ability to invade and associate with perinuclear and nuclear sites.

Isolation of Mycoplasma genitalium from first-void urine specimens by coculture with Vero cells.

Isolation of Mycoplasma genitalium from clinical specimens remains difficult. We describe an improvement of the Vero cell coculture method in which the growth of M. genitalium was monitored by quantitative real-time PCR. Four new M. genitalium strains were isolated from six first-void urine specimens of male Japanese patients with urethritis. In two of them, only M. genitalium was detected: one also contained Ureaplasma urealyticum, and one contained Chlamydia trachomatis, Neisseria gonorrhoeae, U. urealyticum, and Ureaplasma parvum. In the specimens yielding isolates of M. genitalium, growth was documented by quantitative PCR after two to five passages in Vero cells. The complete isolation procedure from the initial inoculation to completion of single-colony cloning took about 1 year. Isolation of M. genitalium from urine specimens proved to be more difficult than from swab specimens. Due to the cytotoxic effect of urine, a procedure involving washing of the urinary sediment was introduced. Furthermore, prolonged storage of the urine specimens before culture was shown to be detrimental to the success of isolation, as shown by the lack of success in attempts to isolate M. genitalium from mailed urine specimens as well as by simulation experiments. High concentrations of penicillin G and amphotericin B were surprisingly inhibitory to the growth of wild-type M. genitalium strains, but penicillin G at 200 IU/ml and polymyxin B at 500 microg/ml could be used as selective antibiotics to avoid bacterial overgrowth in the Vero cell cultures.

Mycoplasma genitalium P140 and P110 cytadhesins are reciprocally stabilized and required for cell adhesion and terminal-organelle development.

Mycoplasma genitalium is a human pathogen that mediates cell adhesion by a complex structure known as the attachment organelle. This structure is composed of cytadhesins and cytadherence-associated proteins, but few data are available about the specific role of these proteins in M. genitalium cytadherence. We have deleted by homologous recombination the mg191 and mg192 genes from the MgPa operon encoding the P140 and P110 cytadhesins. Molecular characterization of these mutants has revealed a reciprocal posttranslational stabilization between the two proteins. Loss of either P140 or P110 yields a hemadsorption-negative phenotype and correlates with decreased or increased levels of cytoskeleton-related proteins MG386 and DnaK, respectively. Scanning electron microscopy analysis reveals the absolute requirement of P140 and P110 for the proper development of the attachment organelle. The phenotype described for these mutants resembles that of the spontaneous class I and class II cytadherence-negative mutants [G. R. Mernaugh, S. F. Dallo, S. C. Holt, and J. B. Baseman, Clin. Infect. Dis. 17(Suppl. 1):S69-S78, 1993], whose genetic basis remained undetermined until now. Complementation assays and sequencing analysis demonstrate that class I and class II mutants are the consequence of large deletions affecting the mg192 and mg191-mg192 genes, respectively. These deletions originated from single-recombination events involving sequences of the MgPa operon and the MgPa island located immediately downstream. We also demonstrate the translocation of MgPa sequences to a particular MgPa island by double-crossover events. Based on these observations, we propose that in addition to being a source of antigenic variation, MgPa islands could be also involved in a general phase variation mechanism switching on and off, in a reversible or irreversible way, the adhesion properties of M. genitalium.

Cervicitis and genitourinary symptoms in women culture positive for Mycoplasma genitalium.

PROBLEM: Mycoplasma genitalium has been associated with male urethritis. We sought to relate M. genitalium to genitourinary signs and symptoms in women. METHOD OF STUDY: We compared 26 culture-positive women (group 1), 257 additional polymerase chain reaction-positive women (group 2), and 107 negative control women. We used logistic regression to evaluate signs and symptoms, controlling for co-infections, pregnancy, age, and intervention group assignment. RESULTS: Comparing group 1 with controls, we found significantly elevated odds ratios (ORs) for intermediate vaginal discharge (OR = 5.4; 95% confidence interval 1.01, 29.2) and action in response to discharge [3.9 (1.1, 13.5)]. Non-significant increases were observed for pathologic vaginal discharge [3.8 (0.78, 18.2)], pathologic dyspareunia [1.5 (0.25, 9.0)], vaginal odor [2.1 (0.75, 5.7)], and cervical mucopus [4.1 (0.74, 22.4)]. Group 2 results were similar, but showed no increase in cervical mucopus relative to controls. CONCLUSION: Infection with M. genitalium in women is independently related to increased genitourinary symptomatology.

Antibiotic susceptibility testing of Mycoplasma genitalium by TaqMan 5' nuclease real-time PCR.

Mycoplasma genitalium is an important pathogen in male nongonococcal urethritis (NGU). Isolation of M. genitalium from clinical specimens by axenic culture is very difficult and time-consuming, and very few strains are available for antibiotic susceptibility testing. Primary isolation of M. genitalium by coculture with Vero cells improves the isolation rate significantly. However, some strains cannot be adapted to axenic culture. In this study, we determined the antibiotic susceptibility of M. genitalium strains grown in Vero cell culture with dilutions of antibiotics. Growth of M. genitalium was monitored by a quantitative PCR assay detecting a single-copy region of the mgpB adhesin gene. Growth inhibition in the presence of antibiotics was expressed as a percentage of the DNA load of controls grown in the absence of antibiotics. Eighteen strains were examined, including 6 new strains isolated from urethral swab specimens and 4 new strains isolated from urine specimens collected from Japanese men. Eight strains adapted to axenic culture were also tested by the conventional broth dilution method. The two methods had an acceptable correlation. Azithromycin was the most active drug against M. genitalium. Among the fluoroquinolones, moxifloxacin had the highest activity, with MICs ranging from 0.03 to 0.5 mg/liter, whereas ciprofloxacin and levofloxacin were considerably less active, with MICs ranging from 0.5 to 16 mg/liter and 0.25 to 4 mg/liter, respectively. MICs for tetracycline ranged from 0.125 to 4 mg/liter. This new method could increase the number of M. genitalium strains available for antibiotic susceptibility testing and significantly shorten the time from sampling to MIC results.

Determination of infectious load of Mycoplasma genitalium in clinical samples of human vaginal cells.

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.