Triplet-pore structure of a highly divergent TOM complex of hydrogenosomes in Trichomonas vaginalis.

Mitochondria originated from proteobacterial endosymbionts, and their transition to organelles was tightly linked to establishment of the protein import pathways. The initial import of most proteins is mediated by the translocase of the outer membrane (TOM). Although TOM is common to all forms of mitochondria, an unexpected diversity of subunits between eukaryotic lineages has been predicted. However, experimental knowledge is limited to a few organisms, and so far, it remains unsettled whether the triplet-pore or the twin-pore structure is the generic form of TOM complex. Here, we analysed the TOM complex in hydrogenosomes, a metabolically specialised anaerobic form of mitochondria found in the excavate Trichomonas vaginalis. We demonstrate that the highly divergent ß-barrel T. vaginalis TOM (TvTom)40-2 forms a translocation channel to conduct hydrogenosomal protein import. TvTom40-2 is present in high molecular weight complexes, and their analysis revealed the presence of four tail-anchored (TA) proteins. Two of them, Tom36 and Tom46, with heat shock protein (Hsp)20 and tetratricopeptide repeat (TPR) domains, can bind hydrogenosomal preproteins and most likely function as receptors. A third subunit, Tom22-like protein, has a short cis domain and a conserved Tom22 transmembrane segment but lacks a trans domain. The fourth protein, hydrogenosomal outer membrane protein 19 (Homp19) has no known homology. Furthermore, our data indicate that TvTOM is associated with sorting and assembly machinery (Sam)50 that is involved in ß-barrel assembly. Visualisation of TvTOM by electron microscopy revealed that it forms three pores and has an unconventional skull-like shape. Although TvTOM seems to lack Tom7, our phylogenetic profiling predicted Tom7 in free-living excavates. Collectively, our results suggest that the triplet-pore TOM complex, composed of three conserved subunits, was present in the last common eukaryotic ancestor (LECA), while receptors responsible for substrate binding evolved independently in different eukaryotic lineages.

Extracellular vesicles released by anaerobic protozoan parasites: Current situation.

Extracellular vesicles (EVs) have emerged as a ubiquitous mechanism for transferring information between cells and organisms across all three kingdoms of life. Parasitic unicellular eukaryotes use EVs as vehicles for intercellular communication and host manipulation. Pathogenic protozoans are able to modulate the immune system of the host and establish infection by transferring a wide range of molecules contained in different types of EVs. In addition to effects on the host, EVs are able to transfer virulence factors, drug-resistance genes and differentiation factors between parasites. In this review we cover the current knowledge on EVs from anaerobic or microaerophilic extracellular protozoan parasites, including Trichomonas vaginalis, Tritrichomonas foetus, Giardia intestinalis and Entamoeba histolytica, with a focus on their potential role in the process of infection. The role of EVs in host: parasite communication adds a new level of complexity to our understanding of parasite biology, and may be a key to understand the complexity behind their mechanism of pathogenesis.

Diagnosis, Treatment, Follow-up, and Persistence of Trichomonas vaginalis in Women 45 Years and Older According to HIV Status: A 10-Year Retrospective Cohort.

BACKGROUND: Trichomonas vaginalis is a common treatable sexually transmitted infection among older women. Persistent T. vaginalis infection after treatment is common among women with human immunodeficiency virus (HIV). We sought to determine if HIV-negative women were as likely as women with HIV to have persistent T. vaginalis infection. METHODS: We performed a retrospective cohort study of women 45 years or older with T. vaginalis infection. We evaluated differences in persistent T. vaginalis infection according to HIV status using χ analysis. We performed regression analyses to describe factors associated with persistent and recurrent infection in older women. RESULTS: Over a 10-year study period, we identified 282 women with T. vaginalis, 46 with HIV. Most women (240, 86%) were treated in accordance with 2015 Centers for Disease Control and Prevention Sexually Transmitted Diseases treatment guidelines. Half of the women (144, 53%) had a repeat T. vaginalis test 90 to 365 days after treatment, and one third had persistent infection (39/125, 31%). Persistent infection was similar between women with HIV and HIV-negative women treated according to Centers for Disease Control recommendations (17% vs 33%, P = 0.3). When adjusting for age and incidental diagnosis, tobacco use was associated with an increased risk of more than 1 or recurrent T. vaginalis infection during the study period (adjusted odds ratio, 2.8; 95% confidence interval, 1.5-4.9). CONCLUSIONS: The HIV status did not affect persistent T. vaginalis infection in women 45 years or older. Given over one third of women have a positive test within a year after the recommended treatment, our data support repeat testing in women 45 years and older treated for T. vaginalis.

Association between Trichomonas vaginalis infection and cervical lesions: a population-based, nested case-control study in Taiwan.

Trichomonas vaginalis is the most common nonviral sexually transmitted infection. According to the 2019 WHO cancer report, cervical cancer is the fourth most frequent cancer in women. However, previous research, which has not included a large-scale study to date, has revealed that Trichomonas vaginalis increases cervical cancer risk. In this study, we investigated a group of Asian females in Taiwan to determine the association between trichomoniasis and the risk of developing cervical lesions, including cancer, neoplasm, and dysplasia. We conducted a nested case-control study by using the National Health Insurance (NHI) program database in Taiwan. The International Classification of Diseases, 9th Revision classifications (ICD-9-CM) was used to categorize all of the medical conditions for each patient in the case and control groups. The adjusted odds ratio (AOR) and 95% confidence interval (CI) for the association between trichomoniasis and cervical lesions were estimated using multivariable conditional logistic regression to adjust for all comorbidities and variables. In total, 54,003 individuals were enrolled in the case group and 216,012 were enrolled in the control group. Trichomonas vaginalis exposure had a significant association with cervical lesions (AOR 2.656, 95% CI = 1.411-5.353, p = 0.003), especially cervical cancer (AOR 3.684, 95% CI = 1.622-6.094, p = 0.001). In patients with both trichomoniasis and depression, the relative risk increased 7.480-fold compared to those without trichomoniasis or depression. In conclusion, female patients with Trichomonas vaginalis exposure had a significantly higher risk of developing cervical lesions (especially cervical cancer) than those without exposure.

Metronidazole and Secnidazole Carbamates: Synthesis, Antiprotozoal Activity, and Molecular Dynamics Studies.

We prepared a series of 10 carbamates derivatives based on two common antiprotozoal drugs: metronidazole (1-5) and secnidazole (6-10). The compounds were tested in vitro against a set of two amitochondriate protozoa: Giardia duodenalis and Trichomonas vaginalis. Compounds 1-10 showed strong antiprotozoal activities, with potency values in the low micromolar-to-nanomolar range, being more active than their parent drugs. Metronidazole carbamate (1) was the most active of the series, with nanomolar activities against G. duodenalis (IC50 = 460 nM) and T. vaginalis (IC50 = 60 nM). The potency of compound 1 was 10 times greater than that of metronidazole against both parasites. None of compounds showed in vitro cytotoxicity against VERO cells tested at 100 µM. Molecular dynamics of compounds 1-10, secnidazole, and metronidazole onto the ligand binding site of pyruvate-ferredoxin oxidoreductase of T. vaginalis and the modeled -tubulin of G. duodenalis revealed putative molecular interactions with key residues in the binding site of both proteins implicated in the mode of action of the parent drugs.

Cooperative Interactions between Trichomonas vaginalis and Associated Bacteria Enhance Paracellular Permeability of the Cervicovaginal Epithelium by Dysregulating Tight Junctions.

The human protozoan Trichomonas vaginalis is the causative agent of trichomoniasis, a prevalent sexually transmitted infection, which is accompanied by a species-diversified vaginal microbiota named community state type IV (CST-IV). Coincidently, CST-IV includes species associated with bacterial vaginosis (e.g. Gardnerella vaginalis, Atopobium vaginae, and Prevotella bivia). Both diseases are linked to the transmission of human immunodeficiency virus (HIV) and preterm birth, which complications are likely to result from the disruption of the cervicovaginal epithelial barrier. Here, we show that paracellular permeability of fluorescein isothiocyanate (FITC)-dextran through a monolayer of human ectocervical cells (hECs) is increased as a consequence of the activity of T. vaginalis and the aforementioned species of CST-IV bacteria cooperatively. T. vaginalis enhances paracellular permeability of hECs two times more than the individual bacterial species, by up to ∼10% versus ∼5%, respectively. However, any two or all three bacterial species are capable of synergizing this effect. T. vaginalis and the bacteria together increase the paracellular permeability of hECs by ∼50%, which is 5 to 10 times more than the results seen with the protozoan or bacteria alone. This effect is accompanied by enhancement of phosphatase activity, while phosphatase inhibition results in preservation of the integrity of the ectocervical cell monolayer. In addition, these microorganisms induce changes in the expression of tight junction proteins, particularly occludin, and of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). Together, our findings establish that cooperative interactions between CST-IV bacteria and T. vaginalis enhance the paracellular permeability of the cervicovaginal epithelium by disturbing the integrity of the tight junction complex. Our study results highlight the importance of understanding the contribution of the vaginal microbiota to trichomoniasis.

Treatment Attitudes for Belgian Women With Persistent Trichomonas vaginalis Infection in the VlaResT Study.

BACKGROUND: Because of its increasing prevalence worldwide, its sexual transmissibility and its facilitation of human immunodeficiency virus transmission, Trichomonas vaginalis (TV) infection constitutes an important public health concern. THE AIM OF THE STUDY: While searching for possible resistant TV cases, adequacy of management of TV-infected women was assessed. METHODS: Cervical cytology between July 2007 and July 2014 was tested with TV polymerase chain reaction, and 304 women expressed repeatedly positive results, 718 in total. For each of these positive results, a questionnaire about treatment decisions was sent to the 182 Belgian physicians treating these women. RESULTS: From the 346 returned questionnaires by their physician it was evident that 58.1% of women with repeatedly positive TV had received no treatment. TV was overlooked in 31.5%, and in 17.6% the test result was seen but ignored. Upon seeing the positive result, 23.9% of physicians decided that this finding was not important enough to institute treatment, and/or requested confirmatory tests. Adequate treatment was prescribed in 38.4%. Retreatment after failed therapy was given in only 29.3% of the cases. And 60% of the partners of women with persistent TV infection were not traced, nor treated. CONCLUSION: Most of the repeatedly positive TV infection may not be due to antibiotics resistance. The low awareness, poor attention, failure of contact tracing, and low rates of proper treatment provided by treating physicians question the adequacy of the current management of TV infection and requires renewed education campaigns and increased surveillance.

Association between Trichomonas vaginalis and prostate cancer mortality.

We previously observed a positive association between seropositivity for the parasite Trichomonas vaginalis and risk of clinically significant prostate cancer at diagnosis. Here, we examined whether T. vaginalis seropositivity was associated with increased prostate cancer-specific or all-cause mortality among prostate cancer patients. We studied 736 men with prostate cancer from the Physicians' Health Study (PHS) and 749 men with prostate cancer from the Health Professionals Follow-Up Study (HPFS). We used Cox proportional hazards regression models to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of the association between T. vaginalis serostatus and progression to death from prostate cancer and from all causes. In PHS, 423 men died of any cause during a median follow-up of 13.8 years from the date of cancer diagnosis, among whom 131 died of prostate cancer. In HPFS, there were 287 deaths, including 77 deaths from prostate cancer, during a median follow-up of 12.8 years. We found no association between T. vaginalis serostatus and either prostate cancer mortality or all-cause mortality in either the PHS or HPFS. While previous studies suggest a possible role for T. vaginalis in the development of clinically significant prostate cancer, our findings do not support the hypothesis that T. vaginalis serostatus is associated with mortality among prostate cancer patients.

Is there association between Trichomonas vaginalis infection and prostate cancer risk?: A systematic review and meta-analysis.

We performed a systematic review and meta-analysis to reveal the association between Trichomonas vaginalis (TV) infection and the risk of prostate cancer (PCa) development. Systematic searching (PubMed/Medline, Scopus, Embase, Web of Science, Cinhal, Wiley, Cochrane, Psychoinfo, ProQuest and Google Scholar) was done, up to March 2018 for case-control studies. Random effects model was applied to define odds ratios and their 95% confidence intervals. In total, 6 enteries were included in our meta-analysis, comprising 5590 individuals (2677 PCa cases and 2913 control individuals) examined for trichomoniasis, with a total positivity of 469 (17.51%) and 482 (16.54%) individuals, respectively. Totally, such association was documented in three countries, including USA (4 studies), Kuwait (one study) and Taiwan (one study). Based on pooled estimations, however a 1.17-time increase of PCa was observed among individuals with a previous exposure of TV, it was not statistically significant [OR = 1.17 (95% CI: 1.01 to 1.36)]. Egger's regression test demonstrated no publication bias among studies. Also, year of publication for included records was not significantly correlated to the relationship between trichomoniasis and PCa. Any further inferences should be based on future investigations for better understanding this relationship and shedding light on the cryptic pathogenesis of TV in PCa patients.

Trichomonas vaginalis and Mycoplasma hominis: new tales of two old friends.

Trichomonas vaginalis is an anaerobic protist, responsible for the most prevalent non-viral sexually transmitted infection in humans. One of the most intriguing aspects of T. vaginalis pathobiology is the complex relationship with intracellular microbial symbionts: a group of dsRNA viruses belonging to family of Totiviridae (T. vaginalis virus), and eubacteria belonging to the Mycoplasma genus, in particular Mycoplasma hominis. Both microorganisms seem to strongly influence the lifestyle of T. vaginalis, suggesting a role of the symbiosis in the high variability of clinical presentation and sequelae during trichomoniasis. In the last few years many aspects of this unique symbiotic relationship have been investigated: M. hominis resides and replicates in the protozoan cell, and T. vaginalis is able to pass the bacterial infection to both mycoplasma-free protozoan isolates and human epithelial cells; M. hominis synergistically upregulates the proinflammatory response of human monocytes to T. vaginalis. Furthermore, the influence of M. hominis over T. vaginalis metabolism and physiology has been characterized. The identification of a novel species belonging to the class of Mollicutes (Candidatus Mycoplasma girerdii) exclusively associated to T. vaginalis opens new perspectives in the research of the complex series of events taking place in the multifaceted world of the vaginal microbiota, both under normal and pathological conditions.

Glucose-restriction increases Trichomonas vaginalis cellular damage towards HeLa cells and proteolytic activity of cysteine proteinases (CPs), such as TvCP2.

Trichomonas vaginalis induces cellular damage to the host cells (cytotoxicity) through the proteolytic activity of multiple proteinases of the cysteine type (CPs). Some CPs are modulated by environmental factors such as iron, zinc, polyamines, etc. Thus, the goal of this study was to assess the effect of glucose on T. vaginalis cytotoxicity, proteolytic activity and the particular role of TvCP2 (TVAG_057000) during cellular damage. Cytotoxicity assays showed that glucose-restriction (GR) promotes the highest HeLa cell monolayers destruction (~95%) by trichomonads compared to those grown under high glucose (~44%) condition. Zymography and Western blot using different primary antibodies showed that GR increased the proteolytic activity, amount and secretion of certain CPs, including TvCP2. We further characterized the effect of glucose on TvCP2. TvCP2 increases in GR, localized in vesicles close to the plasma membrane and on the surface of T. vaginalis. Furthermore, pretreatment of GR-trichomonads with an anti-TvCP2r polyclonal antibody specifically reduced the levels of cytotoxicity and apoptosis induction to HeLa cells in a concentration-dependent manner. In conclusion, our data show that GR, as a nutritional stress condition, promotes trichomonal cytotoxicity to the host cells, increases trichomonad proteolytic activity and amount of CPs, such as TvCP2 involved in cellular damage.

Molecular Detection of Pathogens Causing Sexually Transmissible Infections in Patients with Prostate Cancer and Hyperplasia by Quantitative TaqMan Real-Time PCR Assay.

BACKGROUND: Prostate cancer is considered the most prevalent cancer among men. Recent studies suggest that sex-ually transmissible infections (STIs) may be related to prostate carcinogenesis. Therefore, the aim of this study was to investigate whether STI pathogens (Atopobium vaginae (ATO), Neisseria gonorrhoeae (NG), Chlamydia tra-chomatis (CT), Treponema pallidum (TP), Ureaplasma urealyticum (UU), Gardnerella vaginalis (GV), Herpes Sim-plex Virus (HSV), Cytomegalovirus (CMV), Human herpesvirus (HHV), Human papillomavirus (HPV), and Tricho-monas vaginalis (TV)) presence in prostate tissues are associated with the risk of prostate cancer. METHODS: Paraffin-embedded prostate tissues obtained from patients with hyperplasia and prostate cancer were extracted. Determination of infectious microorganisms of interest was done by quantitative TaqMan real-time PCR assay. RESULTS: STI DNA was detected in 53/243 (21.8%) of the prostate tissues samples (ATO 3.7%, UU 2.88%, GV 2.46%, HSV-2 2.05%, CT 2.05%, CMV 1.64%, NG 1.64%, TP 1.64%, HHV-8 1.23%, HPV 1.23%, and TV 1.23%.) The statistical analysis revealed significant correlation between prevalence of Gardnerella vaginalis (GV) and Herpes Simplex Virus (HSV-2) between hyperplasia and cancerous groups (p = 0.02), respectively. CONCLUSIONS: No statistically significant difference was observed in the prevalence of most candidate infectious or-ganisms between hyperplasia and cancerous groups except for GV and HSV-2. It appears that inflammation in the prostate gland is more associated with prostate hyperplasia than prostate cancer. According to the role of in-fectious microorganisms in induction of chronic inflammation, we cannot exclude the importance of these patho-gens in progression of cancer. More studies are required to explore the associations of cancer with different infec-tious organisms.

Efficacy of netropsin dihydrochloride against the viability, cytopathogenicity and hemolytic activity of Trichomonas vaginalis clinical isolates.

Trichomonas vaginalis (T. vaginalis) is a common sexually transmitted infection, affecting the urogenital tract. Trichomoniasis is customarily treated with metronidazole (MTZ). MTZ is known to cause undesirable side effects and there is several reports on MTZ resistant T. vaginalis. Thus, the present study aimed to in-vitro evaluate the activity of DNA minor groove binder drug ''Netropsin dihydrochloride'' against metronidazole-sensitive T. vaginalis isolates (G and U isolates) and resistant T. vaginalis isolate (ATCC50138) (R isolate). Netropsin was tested at concentrations ranging from 3.5 to 200 µg/ml. It showed effectiveness against all isolates with MLC of 12.5 µg/ml for G and U isolates and of 25 µg/ml for R isolate. Cytotoxicity assay of isolates exposed to the respective MLC of netropsin for 42 h showed a highly significant reduction in the death percentage of MCDK cell line as compared to the effect elicited by drug free controls. The hemolytic activity was evaluated by hemolytic assay and by monitoring the interaction of T. vaginalis isolates with human erythrocytes by inverted microscopy and scanning electron microscopy. The hemolytic assay showed (0%) hemolysis of RBCs incubated with T. vaginalis isolates treated with the corresponding MLC of netropsin for 24 h. Scanning electron microscopy revealed cytoskeletal deformities of netropsin treated isolates. Taken together, these observations suggest that netropsin is a promising therapy for T. vaginalis infection affecting its viability, virulence, cytopathogenic and hemolytic activity with a mechanism of action that might overcome T. vaginalis resistance to metronidazole.

[CLINICAL CASE OF TRICHOMONAS VAGINALIS INVASION OF THE PREGNANT WOMAN AND HER NEWBORN GIRL].

Objective - study of the features of Trichomonas vaginalis invasion in pregnant women and newborns. The cultures of Trichomonas isolated from a pregnant woman, her newborn girl, as well as amniotic fluid were examined. The ultrastructure of the cells was studied using a TEM-125K microscope equipped with a SAI-01A system (SELMI), using a DX 2 CCD camera and the KAPPA software package. The verification of STI pathogens was carried out by PCR, in particular, Trichomonas tenax and Pentatrichomonas hominis were identified by experimental original primers that were developed using real-time PCR (PCR-RT). The invasion of Trichomonas vaginalis of the genital tract of a newborn girl, amniotic fluid and amniotic membrane is characterized clinically and instrumentally. We proved the possibility of Trichomonas vaginalis invasion of newborn children not only during the passage of the child through the infected birth canal, but also due to a defect in the fetal membranes with the development of chorioamnionitis, followed by infection of the amniotic fluid and possible infection of the fetus.

Epigenetics regulates transcription and pathogenesis in the parasite Trichomonas vaginalis.

Trichomonas vaginalis is a common sexually transmitted parasite that colonizes the human urogenital tract. Infections range from asymptomatic to highly inflammatory, depending on the host and the parasite strain. Different T. vaginalis strains vary greatly in their adherence and cytolytic capacities. These phenotypic differences might be attributed to differentially expressed genes as a consequence of extra-genetic variation, such as epigenetic modifications. In this study, we explored the role of histone acetylation in regulating gene transcription and pathogenesis in T. vaginalis. Here, we show that histone 3 lysine acetylation (H3KAc) is enriched in nucleosomes positioned around the transcription start site of active genes (BAP1 and BAP2) in a highly adherent parasite strain; compared with the low acetylation abundance in contrast to that observed in a less-adherent strain that expresses these genes at low levels. Additionally, exposition of less-adherent strain with a specific histone deacetylases inhibitor, trichostatin A, upregulated the transcription of BAP1 and BAP2 genes in concomitance with an increase in H3KAc abundance and chromatin accessibility around their transcription start sites. Moreover, we demonstrated that the binding of initiator binding protein, the transcription factor responsible for the initiation of transcription of ~75% of known T. vaginalis genes, depends on the histone acetylation state around the metazoan-like initiator to which initiator binding protein binds. Finally, we found that trichostatin A treatment increased parasite aggregation and adherence to host cells. Our data demonstrated for the first time that H3KAc is a permissive histone modification that functions to mediate both transcription and pathogenesis of the parasite T. vaginalis.

Humoral and T cell-mediated immune response against trichomoniasis.

Trichomonas vaginalis (T. vaginalis) infection leads to the synthesis of specific antibodies in the serum and local secretions. The profile of T. vaginalis-specific antibodies and T cell-mediated immune responses may influence the outcome of infection, towards parasite elimination, persistence or pathological reactions. Studies have indicated that Th1-, Th17- and Th22 cell-related cytokines may be protective or pathogenic, whereas Th2- and Treg cell-related cytokines can exert anti-inflammatory effects during T. vaginalis infection. A number of T. vaginalis-related components such as lipophosphoglycan (TvLPG), α-actinin, migration inhibitory factor (TvMIF), pyruvate:ferredoxin oxidoreductase (PFO), legumain-1 (TvLEGU-1), adhesins and cysteine proteases lead to the induction of specific antibodies. T. vaginalis has acquired several strategies to evade the humoral immune responses such as degradation of immunoglobulins by cysteine proteases, antigenic variation and killing of antibody-producing B cells. The characterization of the T. vaginalis-specific antibodies to significant immunogenic molecules and formulation of strategies to promote their induction in vaginal mucosa may reveal their potential protective effects against trichomoniasis. In this review, we discuss the current understanding of antibody and T cell-mediated immune responses to T. vaginalis and highlight novel insights into the possible role of immune responses in protection against parasite.

Higher vaginal pH in Trichomonas vaginalis infection with intermediate Nugent score in reproductive-age women-a hospital-based cross-sectional study in Odisha, India.

A close association between Trichomonas vaginalis (TV) infection and bacterial vaginosis (BV) has been reported. Some other studies have found association is stronger with intermediate Nugent score than BV. Most studies have used wet mount microscopy, a relatively insensitive method, to detect TV infection. We wanted to study the association of TV infection with BV and with intermediate Nugent score. We undertook a cross-sectional hospital-based study of 1110 non-pregnant women from Odisha state, India, aged between 18 and 45 years, collecting vaginal swabs for diagnosis of BV by Nugent score (NS) criteria and TV by PCR analysis. TV infection was found in 13.3% of women with intermediate Nugent score (NS 4-6) and 13.6% with BV (NS 7-10). Before adjustment, TV infection was associated with BV, intermediate Nugent, vaginal pH ≥ 4.5, and age group between 26 and 35 years. Multivariate analysis confirmed that TV infection was more likely to have raised vaginal pH, either BV or intermediate Nugent. Proportion of TV cases increased sequentially with the increase in Nugent score up to NS 6, after which a decline was observed. Vaginal pH was higher in the TV-infected group than the uninfected group in women with intermediate Nugent, but no difference was noticed in women with BV. TV infection was equally prevalent in women with intermediate Nugent as well as BV. In the intermediate Nugent group women, TV infection was found only when vaginal pH was raised, indicating a crucial role of vaginal pH in determining TV infection.

A Trichomonas vaginalis Rhomboid Protease and Its Substrate Modulate Parasite Attachment and Cytolysis of Host Cells.

Trichomonas vaginalis is an extracellular eukaryotic parasite that causes the most common, non-viral sexually transmitted infection worldwide. Although disease burden is high, molecular mechanisms underlying T. vaginalis pathogenesis are poorly understood. Here, we identify a family of putative T. vaginalis rhomboid proteases and demonstrate catalytic activity for two, TvROM1 and TvROM3, using a heterologous cell cleavage assay. The two T. vaginalis intramembrane serine proteases display different subcellular localization and substrate specificities. TvROM1 is a cell surface membrane protein and cleaves atypical model rhomboid protease substrates, whereas TvROM3 appears to localize to the Golgi apparatus and recognizes a typical model substrate. To identify TvROM substrates, we interrogated the T. vaginalis surface proteome using both quantitative proteomic and bioinformatic approaches. Of the nine candidates identified, TVAG_166850 and TVAG_280090 were shown to be cleaved by TvROM1. Comparison of amino acid residues surrounding the predicted cleavage sites of TvROM1 substrates revealed a preference for small amino acids in the predicted transmembrane domain. Over-expression of TvROM1 increased attachment to and cytolysis of host ectocervical cells. Similarly, mutations that block the cleavage of a TvROM1 substrate lead to its accumulation on the cell surface and increased parasite adherence to host cells. Together, these data indicate a role for TvROM1 and its substrate(s) in modulating attachment to and lysis of host cells, which are key processes in T. vaginalis pathogenesis.

Incident Trichomonas vaginalis Is Associated With Partnership Concurrency: A Longitudinal Cohort Study.

BACKGROUND: Sexual partner concurrency (PC) has been shown to be a risk factor for a number of sexually transmitted infections but it is unknown if it is a risk factor for Trichomonas vaginalis (TV). OBJECTIVE: We assess if there is an association between PC and incident TV infection. STUDY DESIGN: We used mixed effects logistic regression to assess the association between PC and incident TV in the Longitudinal Study of Vaginal Flora, a cohort study of 3620 women followed quarterly for 5 visits. RESULTS: Trichomonas vaginalis was more common in those reporting definite/possible/unknown PC (15.6%/15.0%/18.3%) than those reporting no PC (5.2%; P < 0.001 for all 3 comparisons). After controlling for a range of confounders, incident TV remained associated with reporting that one's partner definitely (adjusted odds ratio, 5.4; 95% confidence interval, 3.7-8.0) and possibly (adjusted odds ratio, 3.4; 95% confidence interval, 2.2-5.1) engaged in PC in the preceding period. CONCLUSIONS: Partner concurrency was associated with incident TV infection.

Cervical precancerous changes and selected cervical microbial infections, Kiambu County, Kenya, 2014: a cross sectional study.

BACKGROUND: Cervical cancer is the predominant cancer among women in Kenya and second most common in women in developing regions. Population-based cytological screening and early treatment reduces morbidity and mortality associated with the cancer. We determined the occurrence of cervical precancerous changes and cervical microbial infections (Trichomonas vaginalis, Candida albicans, Neisseria gonorrhea and Actinomyces) among women attending Family Health Option Kenya (FHOK) clinic in Thika. METHODS: This was a hospital based cross sectional study among women attending reproductive health screening clinic from November 2013 to January 2014. Cervical Intraepithelial Neoplasia (CIN) I, II, III, cervical cancer and microbial infection (Actinomyces, Trichomonas vaginalis and Yeast cells) diagnosis was based on Pap smear screening test and High Vaginal Swab wet preparation microscopy. Neisseria gonorrhea was diagnosed through Gram staining. Socio-demographic and reproductive health data was collected using a structured questionnaire administered to the study participants and analyzed using Epi Info version 3.5.1. RESULTS: Of the 244 women screened, 238 (97.5%) presented with cervical inflammation, 80 (32.8%) cervical microbial infections and 12 (4.9%) cervical precancerous changes; 10 (83.3%) with CIN I and 2 (16.7%) CIN II. Of the 80 cervical microbial infections, 62 (77.5%) were yeast cell and 18 (22.5%) T. vaginalis. One thirty four (55%) participants had no history of Pap smear screening of which 84 (62.7%) were 20-40 years. Use of IUCDs (OR: 2.47, 95% CI 1.3-4.6) was associated with cervical inflammation. CONCLUSIONS: CIN I was the predominant cervical precancerous change. There is need to scale up cervical screening test to capture all categories of women.