Significance Prostate cancer is the most common nonskin cancer in America and the fifth most common cancer worldwide. Inflammation is implicated in the initiation and progression of prostate cancer; however, sources of inflammation remain unidentified. Trichomonas vaginalis is a prevalent parasite that infects prostate epithelium and is associated with an increase in aggressive prostate cancer. Here, we demonstrate that a secreted T. vaginalis protein homologous to human macrophage migration inhibitory factor elicits antibodies in infected individuals, increases prostate cell proliferation and invasiveness, and induces cellular pathways linked to inflammation. This study demonstrates that a specific parasite-derived protein can mimic its human homolog to increase inflammation and cell proliferation, which, in turn, may result in the promotion and progression of prostate cancer.

The existence of a symbiotic relationship between Trichomonas vaginalis and Mycoplasma hominis, which is the first reported example of symbiosis between two obligate human pathogens, has been recently reported by our research group. In this work, we examined the cellular location of M. hominis in respect to T. vaginalis. By using gentamicin protection assays, double immunofluorescence, and confocal microscopy, we obtained strong evidence that M. hominis is located within protozoan cells. 5-Bromodeoxyuridine incorporation assays showed that intracellularly located mycoplasmas actively synthesize DNA. Our results demonstrate that M. hominis has the capability of entering trichomonad cells and of replicating inside the protozoon. These findings suggest that symbiosis might provide the bacteria, during human infection, with the capability to resist to environmental stresses, such as host defense mechanisms and pharmacological therapies.Trichomonas vaginalis is a parasitic protozoon responsible for trichomoniasis, one of the most common sexually transmitted diseases in humans, estimated to affect at least 200 million people worldwide (37). Studies carried out with large groups of women suffering from vaginitis showed that T. vaginalis is clinically associated with Mycoplasma hominis (18, 35), a bacterium that, like the protozoon, resides exclusively in the human genital tract. The association is strictly species specific, since is not observed with Ureaplasma urealyticum, another Mollicutes species that is a much more common inhabitant of the human genital tract. The clinical association between the two pathogens has been recently explained by the demonstration of a symbiotic relationship between T. vaginalis and M. hominis (27). More than 90% of T. vaginalis clinical isolates from our collection proved to be infected by M. hominis independent of their geographic origin. Our recent work has allowed us to shed light on some aspects of the phenomenon (28).The presence of endosymbionts in free-living protozoa is frequently described, but it has been never reported in obligate parasitic protozoa. The first example of symbiosis involving a human pathogen was described for Legionella pneumophila, a bacterial pathogen that is responsible for Legionnaire's disease, and Acanthamoeba sp., a free-living opportunistic amoeba (30). The relationship between T. vaginalis and M. hominis is the only one described so far involving two obligate human pathogens. T. vaginalis is responsible for severe vaginitis accompanied by abdominal pain, itching, and foul-smelling discharge (29) and is mainly asymptomatic in men (20). Moreover, trichomoniasis is associated with an enhanced risk of neoplastic transformation in cervical tissues (38) and increased human immunodeficiency virus seroconversion in women (22,31). The mechanisms by which T. vaginalis exerts its pathogenic effects involve adhesion to host cells (1, 2, 19) and the activity of pH-dependent pore-forming proteins (14, 15) and of cytoskeleton-disrupting proteases (16). M. hominis c...

A study was conducted on the circulation of potentially diarrheagenic Escherichia coli in two groups of children, both under the age of seven. The first group (548 children) suffered from mild diarrhea and attended the Xipamanine Health Center of Maputo, in Mozambique. The second group (380 children) included randomly chosen, asymptomatic, children from the same population. A total of 503 E. coli strains were isolated from the two groups of children (n=375 and 128, respectively). All E. coli strains were genotypically and phenotypically screened. The presence of virulence-associated genes was assessed by a set of multiplex PCR specific for st and lt genes of enterotoxic Escherichia coli (ETEC), eae and bfpA genes of enteropathogenic E. coli (EPEC), stx(1) and stx(2) of enterohemorrhagic E. coli (EHEC), ial of enteroinvasive E. coli (EIEC) and the species-specific gene uidA. Adhesion and citotoxicity of isolated E. coli were evaluated in vitro on different cell cultures. A total of 37 isolates harbored virulence-associated genes: 18 were classified as ETEC, (15 from symptomatic, and three from asymptomatic children), 16 as EPEC (respectively, 13 and 3) and three EIEC in the symptomatic group. No stx(1) or stx(2) genes, associated with enterohemorrhagic E. coli were found. On the basis of the adhesion pattern on HeLa cells, 167 E. coli were classified as diffusely adhering, (125 in patients and 42 in controls) and 67 as enteroaggregative, (50 and 17, respectively). To the best of our knowledge, this is the first report in the literature on the circulation of potentially diarrheagenic E. coli in Mozambique.

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.

These findings suggest that the presence of M hominis in T vaginalis isolates might play a key role in inflammation during trichomoniasis, thus affecting the severity of the disease. The synergistic upregulation of the macrophage proinflammatory response might also affect some important clinical conditions associated with T vaginalis infection, such as the increased risk of acquiring cervical cancer or HIV, which are thought to be affected by the inflammatory milieu during trichomoniasis.