Project description:Mycoplasma genitalium is the causative agent of non-gonococcal, chlamydia-negative urethritis in men and has been linked to reproductive tract disease syndromes in women. As with other mycoplasmas, M. genitalium lacks many regulatory genes because of its streamlined genome and total dependence on a parasitic existence. Therefore, it is important to understand how gene regulation occurs in M. genitalium, particularly in response to environmental signals likely to be encountered in vivo. In this study, we developed an oligonucleotide-based microarray to investigate transcriptional changes in M. genitalium following osmotic shock. Using a physiologically relevant osmolarity condition (0.3 M sodium chloride), we identified 39 up-regulated and 72 down-regulated genes. Of the up-regulated genes, 21 were of unknown function and 15 encoded membrane-associated proteins. The majority of down-regulated genes encoded enzymes involved in energy metabolism and components of the protein translation process. These data provide insight into the in vivo response of M. genitalium to hyperosmolarity conditions and identify candidate genes that may contribute to mycoplasma survival in the urogenital tract.
Project description:Little is known regarding the extent or targets of phosphorylation in mycoplasmas, yet in many other bacterial species phosphorylation is known to play an important role in signaling and regulation of cellular processes. To determine the prevalence of phosphorylation in mycoplasmas, we examined the CHAPS-soluble protein fractions of Mycoplasma genitalium and Mycoplasma pneumoniae by two-dimensional gel electrophoresis (2-DE), using a combination of Pro-Q Diamond phosphoprotein stain and 33P labeling. Protein spots that were positive for phosphorylation were identified by peptide mass fingerprinting using MALDI-TOF-TOF mass spectrometry.We identified a total of 24 distinct phosphoproteins, about 3% and 5% of the total protein complement in M. pneumoniae and M. genitalium, respectively, indicating that phosphorylation occurs with prevalence similar to many other bacterial species. Identified phosphoproteins include pyruvate dehydrogenase E1 alpha and beta subunits, enolase, heat shock proteins DnaK and GroEL, elongation factor Tu, cytadherence accessory protein HMW3, P65, and several hypothetical proteins. These proteins are involved in energy metabolism, carbohydrate metabolism, translation/transcription and cytadherence. Interestingly, fourteen of the 24 phosphoproteins we identified (58%) were previously reported as putatively associated with a cytoskeleton-like structure that is present in the mycoplasmas, indicating a potential regulatory role for phosphorylation in this structure.This study has shown that phosphorylation in mycoplasmas is comparable to that of other bacterial species. Our evidence supports a link between phosphorylation and cytadherence and/or a cytoskeleton-like structure, since over half of the proteins identified as phosphorylated have been previously associated with these functions. This opens the door to further research into the purposes and mechanisms of phosphorylation for mycoplasmas.
Project description:Mycoplasma genitalium is the causative agent of non-gonococcal, chlamydia-negative urethritis in men and has been linked to reproductive tract disease syndromes in women. As with other mycoplasmas, M. genitalium lacks many regulatory genes because of its streamlined genome and total dependence on a parasitic existence. Therefore, it is important to understand how gene regulation occurs in M. genitalium, particularly in response to environmental signals likely to be encountered in vivo. In this study, we developed an oligonucleotide-based microarray to investigate transcriptional changes in M. genitalium following osmotic shock. Using a physiologically relevant osmolarity condition (0.3 M sodium chloride), we identified 39 up-regulated and 72 down-regulated genes. Of the up-regulated genes, 21 were of unknown function and 15 encoded membrane-associated proteins. The majority of down-regulated genes encoded enzymes involved in energy metabolism and components of the protein translation process. These data provide insight into the in vivo response of M. genitalium to hyperosmolarity conditions and identify candidate genes that may contribute to mycoplasma survival in the urogenital tract. To examine the effects of hyperosmolarity on M. genitalium transcription, four 50 ml cultures of strain G37 in 75 cm2 tissue culture flasks (Corning) were grown to exponential phase, as determined by medium colour change and colony density. Then, NaCl was added to three flasks to achieve final concentrations of 0.1, 0.2 and 0.3 M. Parallel cultures of M. genitalium in the absence of NaCl served as controls. All cultures were incubated for 1 h at 37M-bM-^DM-^C prior to RNA extraction. Experiments were repeated six times, which produced six independent RNA sample pairs from NaCl-treated cultures and control cultures for each NaCl condition. Dye swap was performed on three of six RNA pairs to minimize effects caused by biased labelling efficiencies.
Project description:We report a case of Mycoplasma genitalium endocarditis in a prosthetic heart valve of a woman who sought care in Switzerland for acute aortic valve dysfunction 3 years after valve replacement. This unusual manifestation of infection with this bacterium was diagnosed using broad-range PCR despite suspicion of a mechanical disinsertion.
Project description:Mycoplasma genitalium is associated with acute and chronic urethritis in men. Existing data on infection in women are limited and inconsistent but suggest that M. genitalium is associated with urethritis, cervicitis, pelvic inflammatory disease, and possibly female infertility. Data are inconclusive regarding the role of M. genitalium in adverse pregnancy outcomes and ectopic pregnancy. Available data suggest that azithromycin is superior to doxycycline in treating M. genitalium infection. However, azithromycin-resistant infections have been reported in 3 continents, and the proportion of azithromycin-resistant M. genitalium infection is unknown. Moxifloxacin is the only drug that currently seems to uniformly eradicate M. genitalium. Detection of M. genitalium is hampered by the absence of a commercially available diagnostic test. Persons with persistent pelvic inflammatory disease or clinically significant persistent urethritis or cervicitis should be tested for M. genitalium, if possible. Infected persons who have not previously received azithromycin should receive that drug. Persons in whom azithromycin therapy fails should be treated with moxifloxicin.
Project description:In Japan and Australia, multidrug-resistant Mycoplasma genitalium infections are reported with increasing frequency. Although macrolide-resistant M. genitalium strains are common in Europe and North America, fluoroquinolone-resistant strains are still exceptional. However, an increase of multidrug-resistant M. genitalium in Europe and America is to be expected. The aim of this paper is to increase awareness on the rising number of multidrug-resistant M. genitalium strains. Here, one of the first cases of infection with a genetically proven multidrug-resistant M. genitalium strain in Europe is described. The patient was a native Dutch 47-year-old male patient with urethritis. Mycoplasma genitalium was detected, but treatment failed with azithromycin, doxycycline and moxifloxacin. A urogenital sample was used to determine the sequence of the 23S rRNA, gyrA, gyrB and parC genes. The sample contained an A2059G single nucleotide polymorphism (SNP) in the 23S rRNA gene and an SNP in the parC gene, resulting in an amino acid change of Ser83 → Ile, explaining both azithromycin and moxifloxacin treatment failure. The SNPs associated with resistance were probably generated de novo, as a link with high-prevalence areas was not established. It is, thus, predictable that there is going to be an increase of multidrug-resistant M. genitalium strains in Europe. As treatment options for multidrug-resistant M. genitalium are limited, the treatment of M. genitalium infections needs to be carefully considered in order to limit the rapid increase of resistance to macrolides and fluoroquinolones.
Project description:Homologous recombination between repeated DNA elements in the genomes of Mycoplasma species has been hypothesized to be a crucial causal factor in sequence variation of antigenic proteins at the bacterial surface. To investigate this notion, studies were initiated to identify and characterize the proteins that form part of the homologous DNA recombination machinery in Mycoplasma pneumoniae as well as Mycoplasma genitalium. Among the most likely participants of this machinery are homologs of the Holliday junction migration motor protein RuvB. In both M. pneumoniae and M. genitalium, genes have been identified that have the capacity to encode RuvB homologs (MPN536 and MG359, respectively). Here, the characteristics of the MPN536- and MG359-encoded proteins (the RuvB proteins from M. pneumoniae strain FH [RuvB(FH)] and M. genitalium [RuvB(Mge)], respectively) are described. Both RuvB(FH) and RuvB(Mge) were found to have ATPase activity and to bind DNA. In addition, both proteins displayed divalent cation- and ATP-dependent DNA helicase activity on partially double-stranded DNA substrates. The helicase activity of RuvB(Mge), however, was significantly lower than that of RuvB(FH). Interestingly, we found RuvB(FH) to be expressed exclusively by subtype 2 strains of M. pneumoniae. In strains belonging to the other major subtype (subtype 1), a version of the protein is expressed (the RuvB protein from M. pneumoniae strain M129 [RuvB(M129)]) that differs from RuvB(FH) in a single amino acid residue (at position 140). In contrast to RuvB(FH), RuvB(M129) displayed only marginal levels of DNA-unwinding activity. These results demonstrate that M. pneumoniae strains (as well as closely related Mycoplasma spp.) can differ significantly in the function of components of their DNA recombination and repair machinery.