The Prevalence of Genital Mycoplasmas and Coinfection with Trichomonas vaginalis in Female Patients in Vienna, Austria.

Trichomonas vaginalis causes trichomoniasis, the most recurrent sexually transmitted infection (STI) worldwide. Genital mycoplasmas, not considered STI agents, are frequently isolated from the female genital tract. A symbiosis between Mycoplasma species and T. vaginalis has been described. The aim of this study was to conduct molecular-based analyses of vaginal specimens, thus assessing the prevalence of non-STI Mycoplasma infections. In total, 582 samples from female patients and an additional 20 T. vaginalis isolates were analyzed by PCR using Mycoplasma specific 16S rRNA primers, and the obtained PCR products were sequenced. Mycoplasma species were detected in 28.2% of the collected vaginal samples. Mycoplasma hominis was found in 21.5% of the specimens, Ureaplasma species were found in 7.5% of the samples. The molecular data of the newly described species, CandidatusMycoplasma girerdii, were obtained for the first time in Austria, in a sample also positive for T. vaginalis. Analyses of the cultivated T. vaginalis strains confirmed the presence of M. hominis in two out of 20 samples. A comparably high prevalence of genital mycoplasmas was revealed through advanced diagnostic assays, with M. hominis and U. parvum being the most prevalent species. The previously described symbiotic relationship between M. hominis and T. vaginalis was confirmed.

Mycoplasma hominis and Candidatus Mycoplasma girerdii in Trichomonas vaginalis: Peaceful Cohabitants or Contentious Roommates?

Trichomonas vaginalis is a pathogenic protozoan diffused worldwide capable of infecting the urogenital tract in humans, causing trichomoniasis. One of its most intriguing aspects is the ability to establish a close relationship with endosymbiotic microorganisms: the unique association of T. vaginalis with the bacterium Mycoplasma hominis represents, to date, the only example of an endosymbiosis involving two true human pathogens. Since its discovery, several aspects of the symbiosis between T. vaginalis and M. hominis have been characterized, demonstrating that the presence of the intracellular guest strongly influences the pathogenic characteristics of the protozoon, making it more aggressive towards host cells and capable of stimulating a stronger proinflammatory response. The recent description of a further symbiont of the protozoon, the newly discovered non-cultivable mycoplasma Candidatus Mycoplasma girerdii, makes the picture even more complex. This review provides an overview of the main aspects of this complex microbial consortium, with particular emphasis on its effect on protozoan pathobiology and on the interplays among the symbionts.

Evolutionary conservation of Trichomonas-mycoplasma symbiosis across the host species barrier.

Introduction: The protozoan parasite Trichomonas vaginalis is the most common cellular sexually transmitted disease in humans, and the closely related species Trichomonas gallinae is an avian parasite of ecological and economic importance. Phylogenetic evidence suggests T. vaginalis arose during bird to human transmission of a T. gallinae-like ancestor. Trichomonas vaginalis shares a strong clinical association with the independent sexually transmitted pathogen Metamycoplasma (formerly Mycoplasma) hominis, and the uncultured bacterium "Candidatus Malacoplasma (formerly Mycoplasma) girerdii," with the latter association being an order of magnitude stronger. Both bacterial species have been shown to profoundly influence T. vaginalis growth, energy production and virulence-associated mechanisms. Methods: Evidence for a novel Malacoplasma sp. was discovered by in vivo Illumina metatranscriptomics sequencing of the T. gallinae-infected pigeon mouth. We leveraged published 16S rDNA profiling data from digestive tract of 12 healthy and 24 T. gallinae-infected pigeons to investigate association between the novel Malacoplasma sp. and T. gallinae. We utilised Illumina metagenomics sequencing targeted to pigeon oral and crop samples infected with the novel Malacoplasma sp. to generate its full-length genome sequence. Sequence similarity network analysis was used to compare annotated proteins from the novel Malacoplasma sp. with a range of other related species. Results: Here we present evidence for a novel Malacoplasma species, related to "Ca. M. girerdii," that is strongly associated with T. gallinae in the upper digestive tract of domestic pigeons. Analysis of the genome sequence revealed gene features apparently specific to a Trichomonas-symbiotic Malacoplasma lineage. Discussion: These data support a model of long-term association between Trichomonas and Malacoplasma spp. that has been conserved across diversification of the Trichomonas lineage and the host species barrier from birds to human.

Two Different Species of Mycoplasma Endosymbionts Can Influence Trichomonas vaginalis Pathophysiology.

Trichomonas vaginalis can host the endosymbiont Mycoplasma hominis, an opportunistic pathogenic bacterium capable of modulating T. vaginalis pathobiology. Recently, a new noncultivable mycoplasma, "Candidatus Mycoplasma girerdii," has been shown to be closely associated with women affected by trichomoniasis, suggesting a biological association. Although several features of "Ca. M. girerdii" have been investigated through genomic analysis, the nature of the potential T. vaginalis-"Ca. M. girerdii" consortium and its impact on the biology and pathogenesis of both microorganisms have not yet been explored. Here, we investigate the association between "Ca. M. girerdii" and T. vaginalis isolated from patients affected by trichomoniasis, demonstrating their intracellular localization. By using an in vitro model system based on single- and double-Mycoplasma infection of Mycoplasma-free isogenic T. vaginalis, we investigated the ability of the protist to establish a relationship with the bacteria and impact T. vaginalis growth. Our data indicate likely competition between M. hominis and "Ca. M. girerdii" while infecting trichomonad cells. Comparative dual-transcriptomics data showed major shifts in parasite gene expression in response to the presence of Mycoplasma, including genes associated with energy metabolism and pathogenesis. Consistent with the transcriptomics data, both parasite-mediated hemolysis and binding to host epithelial cells were significantly upregulated in the presence of either Mycoplasma species. Taken together, these results support a model in which this microbial association could modulate the virulence of T. vaginalis. IMPORTANCE T. vaginalis and M. hominis form a unique case of endosymbiosis that modulates the parasite's pathobiology. Recently, a new nonculturable mycoplasma species ("Candidatus Mycoplasma girerdii") has been described as closely associated with the protozoon. Here, we report the characterization of this endosymbiotic relationship. Clinical isolates of the parasite demonstrate that mycoplasmas are common among trichomoniasis patients. The relationships are studied by devising an in vitro system of single and/or double infections in isogenic protozoan recipients. Comparative growth experiments and transcriptomics data demonstrate that the composition of different microbial consortia influences the growth of the parasite and significantly modulates its transcriptomic profile, including metabolic enzymes and virulence genes such as adhesins and pore-forming proteins. The data on modulation from RNA sequencing (RNA-Seq) correlated closely with those of the cytopathic effect and adhesion to human target cells. We propose the hypothesis that the presence and the quantitative ratios of endosymbionts may contribute to modulating protozoan virulence. Our data highlight the importance of considering pathogenic entities as microbial ecosystems, reinforcing the importance of the development of integrated diagnostic and therapeutic strategies.

Effect of the Symbiosis with Mycoplasma hominis and Candidatus Mycoplasma Girerdii on Trichomonas vaginalis Metronidazole Susceptibility.

Trichomoniasis, the most common non-viral sexually transmitted infection worldwide, is caused by the protozoon Trichomonas vaginalis. The 5- nitroimidazole drugs, of which metronidazole is the most prescribed, are the only effective drugs to treat trichomoniasis. Resistance against metronidazole is increasingly reported among T. vaginalis isolates. T. vaginalis can establish an endosymbiosis with two Mycoplasma species, Mycoplasma hominis and Candidatus Mycoplasma girerdii, whose presence has been demonstrated to influence several aspects of the protozoan pathobiology. The role of M. hominis in T. vaginalis resistance to metronidazole is controversial, while the influence of Ca. M. girerdii has never been investigated. In this work, we investigate the possible correlation between the presence of Ca. M. girerdii and/or M. hominis and the in vitro drug susceptibility in a large group of T. vaginalis isolated in Italy and in Vietnam. We also evaluated, via RNA-seq analysis, the expression of protozoan genes involved in metronidazole resistance in a set of syngenic T. vaginalis strains, differing only for the presence/absence of the two Mycoplasmas. Our results show that the presence of M. hominis significantly increases the sensitivity to metronidazole in T. vaginalis and affects gene expression. On the contrary, the symbiosis with Candidatus Mycoplasma girerdii seems to have no effect on metronidazole resistance in T. vaginalis.

High Co-Infection Rate of Trichomonas vaginalis and Candidatus Mycoplasma Girerdii in Gansu Province, China.

Trichomonas vaginalis (Tv) is a flagellated protist parasite that infects the human urogenital tract. The symbiotic relationship between Tv and Mycoplasma hominis has been reported. Recent studies have identified a new Mycoplasma strain, Candidatus Mycoplasma girerdii (Ca. M. girerdii), present in the vaginal secretions of women and have shown that this strain may be related to trichomoniasis. Here, we evaluated the presence of Tv, M. hominis and Ca. M. girerdii in 312 clinical samples from adult women diagnosed with vaginitis in Zhangye, Gansu province, China. Among these samples, 94, 153, and 48 were Tv, M. hominis and Ca. M. girerdii positive, respectively. Moreover, Tv was highly frequent in 17-30-year-old women in this region. Forty samples (83.3%) positive for Ca. M. girerdii were also positive for Tv. Six Tv isolates were successfully cultured, including five isolates that showed symbiotic relationships with Mycoplasma. This is the first report to evaluate the genetic characteristics of Ca. M. girerdii in China and may therefore provide insights into the effects of Ca. M. girerdii on the reproductive health of women.

Trichomonas vaginalis infection in symbiosis with Trichomonasvirus and Mycoplasma.

Trichomonas vaginalis is a protozoan with an extracellular obligatory parasitic lifestyle exclusively adapted to the human urogenital tract and responsible for nearly a quarter billion sexually transmitted infections worldwide each year. This review focuses on symbiotic Trichomonasvirus and mycoplasmas carried by the protozoan, their molecular features and their role in altering the human vaginal microbiome and the immunopathogenicity of the parasite. Improved diagnostics and larger clinical interventional studies are needed to confirm the causative role of protozoan symbionts in the variable clinical presentation of trichomoniasis and its morbid sequelae, including adverse reproductive outcome, susceptibility to viral infections and cancer.

Detecting the Diversity of Mycoplasma and Ureaplasma Endosymbionts Hosted by Trichomonas vaginalis Isolates.

Objectives: The symbiosis of Trichomonas vaginalis and Mycoplasma hominis is the first described association between two obligate human parasites. Trichomonas is the niche and the vector for the transmission of M. hominis infection. This clinically significant symbiosis may affect T. vaginalis virulence and susceptibility to treatment. The aims of this study were to investigate the intracellularly present Mycoplasma and Ureaplasma species in T. vaginalis strains isolated from the vaginal discharge of infected women as well as to trace the diversity pattern among the species detected in the isolated strains. Methods: Hundred pure T. vaginalis cultures were isolated from ~7,500 patient specimens presented with clinical purulent vaginitis. PCR and sequencing for Mycoplasma/Ureaplasma spp. were performed in DNA extracted from the pure cultures. In addition, vaginal discharge samples were cultured for the presence of M. hominis and U. urealyticum. Phylogenetic analysis assisted the identification of interspecies relationships between the Mycoplasma and Ureaplasma isolates. Results: Fifty four percentage of T. vaginalis isolates were harboring Mycoplasma spp. Phylogenetic analysis revealed three distinct clusters, two with already characterized M. hominis and Ureaplasma spp. (37% of total Mycoplasma spp.), whereas one group formed a distinct cluster matched with the newly identified species Candidatus Mycoplasma girerdii (59.3%) and one or more unknown Mycoplasma spp. (3.7%). Conclusions:T. vaginalis strains associated with vaginal infection might host intracellular mycoplasmas or ureaplasmas. Intracellular Mollicutes that remain undetected in the extracellular environment when conventional diagnostic methods are implemented may comprise either novel species, such as Candidatus M. giredii, or unknown species with yet unexplored clinical significance.