Trichomonas vaginalis extracellular vesicles up-regulate and directly transfer adherence factors promoting host cell colonization.

Trichomonas vaginalis, a common sexually transmitted parasite that colonizes the human urogenital tract, secretes extracellular vesicles (TvEVs) that are taken up by human cells and are speculated to be taken up by parasites as well. While the crosstalk between TvEVs and human cells has led to insight into host:parasite interactions, roles for TvEVs in infection have largely been one-sided, with little known about the effect of TvEV uptake by T. vaginalis. Approximately 11% of infections are found to be coinfections of multiple T. vaginalis strains. Clinical isolates often differ in their adherence to and cytolysis of host cells, underscoring the importance of understanding the effects of TvEV uptake within the parasite population. To address this question, our lab tested the ability of a less adherent strain of T. vaginalis, G3, to take up fluorescently labeled TvEVs derived from both itself (G3-EVs) and TvEVs from a more adherent strain of the parasite (B7RC2-EVs). Here, we showed that TvEVs generated from the more adherent strain are internalized more efficiently compared to the less adherent strain. Additionally, preincubation of G3 parasites with B7RC2-EVs increases parasite aggregation and adherence to host cells. Transcriptomics revealed that TvEVs up-regulate expression of predicted parasite membrane proteins and identified an adherence factor, heteropolysaccharide binding protein (HPB2). Finally, using comparative proteomics and superresolution microscopy, we demonstrated direct transfer of an adherence factor, cadherin-like protein, from TvEVs to the recipient parasite's surface. This work identifies TvEVs as a mediator of parasite:parasite communication that may impact pathogenesis during mixed infections.

Role of a novel uropod-like cell membrane protrusion in the pathogenesis of the parasite Trichomonas vaginalis.

Trichomonas vaginalis causes trichomoniasis, the most common non-viral sexually transmitted disease worldwide. As an extracellular parasite, adhesion to host cells is essential for the development of infection. During attachment, the parasite changes its tear ovoid shape to a flat ameboid form, expanding the contact surface and migrating through tissues. Here, we have identified a novel structure formed at the posterior pole of adherent parasite strains, resembling the previously described uropod, which appears to play a pivotal role as an anchor during the attachment process. Moreover, our research demonstrates that the overexpression of the tetraspanin T. vaginalis TSP5 protein (TvTSP5), which is localized on the cell surface of the parasite, notably enhances the formation of this posterior anchor structure in adherent strains. Finally, we demonstrate that parasites that overexpress TvTSP5 possess an increased ability to adhere to host cells, enhanced aggregation and reduced migration on agar plates. Overall, these findings unveil novel proteins and structures involved in the intricate mechanisms of T. vaginalis interactions with host cells.

The retromer and retriever systems are conserved and differentially expanded in parabasalids.

Early endosomes sort transmembrane cargo either for lysosomal degradation or retrieval to the plasma membrane or the Golgi complex. Endosomal retrieval in eukaryotes is governed by the anciently homologous retromer or retriever complexes. Each comprises a core tri-protein subcomplex, membrane-deformation proteins and interacting partner complexes, together retrieving a variety of known cargo proteins. Trichomonas vaginalis, a sexually transmitted human parasite, uses the endomembrane system for pathogenesis. It has massively and selectively expanded its endomembrane protein complement, the evolutionary path of which has been largely unexplored. Our molecular evolutionary study of retromer, retriever and associated machinery in parabasalids and its free-living sister lineage of Anaeramoeba demonstrates specific expansion of the retromer machinery, contrasting with the retriever components. We also observed partial loss of the Commander complex and sorting nexins in Parabasalia but complete retention in Anaeramoeba. Notably, we identified putative parabasalid sorting nexin analogs. Finally, we report the first retriever protein localization in a non-metazoan group along with retromer protein localization in T. vaginalis.

NlpC/P60 peptidoglycan hydrolases of Trichomonas vaginalis have complementary activities that empower the protozoan to control host-protective lactobacilli.

Trichomonas vaginalis is a human protozoan parasite that causes trichomoniasis, a prevalent sexually transmitted infection. Trichomoniasis is accompanied by a shift to a dysbiotic vaginal microbiome that is depleted of lactobacilli. Studies on co-cultures have shown that vaginal bacteria in eubiosis (e.g. Lactobacillus gasseri) have antagonistic effects on T. vaginalis pathogenesis, suggesting that the parasite might benefit from shaping the microbiome to dysbiosis (e.g. Gardnerella vaginalis among other anaerobes). We have recently shown that T. vaginalis has acquired NlpC/P60 genes from bacteria, expanding them to a repertoire of nine TvNlpC genes in two distinct clans, and that TvNlpCs of clan A are active against bacterial peptidoglycan. Here, we expand this characterization to TvNlpCs of clan B. In this study, we show that the clan organisation of NlpC/P60 genes is a feature of other species of Trichomonas, and that Histomonas meleagridis has sequences related to one clan. We characterized the 3D structure of TvNlpC_B3 alone and with the inhibitor E64 bound, probing the active site of these enzymes for the first time. Lastly, we demonstrated that TvNlpC_B3 and TvNlpC_B5 have complementary activities with the previously described TvNlpCs of clan A and that exogenous expression of these enzymes empower this mucosal parasite to take over populations of vaginal lactobacilli in mixed cultures. TvNlpC_B3 helps control populations of L. gasseri, but not of G. vaginalis, which action is partially inhibited by E64. This study is one of the first to show how enzymes produced by a mucosal protozoan parasite may contribute to a shift on the status of a microbiome, helping explain the link between trichomoniasis and vaginal dysbiosis. Further understanding of this process might have significant implications for treatments in the future.

PIP2 regulating calcium signal modulates actin cytoskeleton-dependent cytoadherence and cytolytic capacity in the protozoan parasite Trichomonas vaginalis.

Trichomonas vaginalis is a prevalent causative agent that causes trichomoniasis leading to uropathogenic inflammation in the host. The crucial role of the actin cytoskeleton in T. vaginalis cytoadherence has been established but the associated signaling has not been fully elucidated. The present study revealed that the T. vaginalis second messenger PIP2 is located in the recurrent flagellum of the less adherent isolate and is more abundant around the cell membrane of the adherent isolates. The T. vaginalis phosphatidylinositol-4-phosphate 5-kinase (TvPI4P5K) with conserved activity phosphorylating PI(4)P to PI(4, 5)P2 was highly expressed in the adherent isolate and partially colocalized with PIP2 on the plasma membrane but with discrete punctate signals in the cytoplasm. Plasma membrane PIP2 degradation by phospholipase C (PLC)-dependent pathway concomitant with increasing intracellular calcium during flagellate-amoeboid morphogenesis. This could be inhibited by Edelfosine or BAPTA simultaneously repressing parasite actin assembly, morphogenesis, and cytoadherence with inhibitory effects similar to the iron-depleted parasite, supporting the significance of PIP2 and iron in T. vaginalis colonization. Intriguingly, iron is required for the optimal expression and cell membrane trafficking of TvPI4P5K for in situ PIP2 production, which was diminished in the iron-depleted parasites. TvPI4P5K-mediated PIP2 signaling may coordinate with iron to modulate T. vaginalis contact-dependent cytolysis to influence host cell viability. These observations provide novel insights into T. vaginalis cytopathogenesis during the host-parasite interaction.

A hybrid TIM complex mediates protein import into hydrogenosomes of Trichomonas vaginalis.

BACKGROUND: Hydrogenosomes are a specific type of mitochondria that have adapted for life under anaerobiosis. Limited availability of oxygen has resulted in the loss of the membrane-associated respiratory chain, and consequently in the generation of minimal inner membrane potential (Δψ), and inefficient ATP synthesis via substrate-level phosphorylation. The changes in energy metabolism are directly linked with the organelle biogenesis. In mitochondria, proteins are imported across the outer membrane via the Translocase of the Outer Membrane (TOM complex), while two Translocases of the Inner Membrane, TIM22, and TIM23, facilitate import to the inner membrane and matrix. TIM23-mediated steps are entirely dependent on Δψ and ATP hydrolysis, while TIM22 requires only Δψ. The character of the hydrogenosomal inner membrane translocase and the mechanism of translocation is currently unknown. RESULTS: We report unprecedented modification of TIM in hydrogenosomes of the human parasite Trichomonas vaginalis (TvTIM). We show that the import of the presequence-containing protein into the hydrogenosomal matrix is mediated by the hybrid TIM22-TIM23 complex that includes three highly divergent core components, TvTim22, TvTim23, and TvTim17-like proteins. The hybrid character of the TvTIM is underlined by the presence of both TvTim22 and TvTim17/23, association with small Tim chaperones (Tim9-10), which in mitochondria are known to facilitate the transfer of substrates to the TIM22 complex, and the coupling with TIM23-specific ATP-dependent presequence translocase-associated motor (PAM). Interactome reconstruction based on co-immunoprecipitation (coIP) and mass spectrometry revealed that hybrid TvTIM is formed with the compositional variations of paralogs. Single-particle electron microscopy for the 132-kDa purified TvTIM revealed the presence of a single ring of small Tims complex, while mitochondrial TIM22 complex bears twin small Tims hexamer. TvTIM is currently the only TIM visualized outside of Opisthokonta, which raised the question of which form is prevailing across eukaryotes. The tight association of the hybrid TvTIM with ADP/ATP carriers (AAC) suggests that AAC may directly supply ATP for the protein import since ATP synthesis is limited in hydrogenosomes. CONCLUSIONS: The hybrid TvTIM in hydrogenosomes represents an original structural solution that evolved for protein import when Δψ is negligible and remarkable example of evolutionary adaptation to an anaerobic lifestyle.

A riboside hydrolase that salvages both nucleobases and nicotinamide in the auxotrophic parasite Trichomonas vaginalis.

Pathogenic parasites of the Trichomonas genus are causative agents of sexually transmitted diseases affecting millions of individuals worldwide and whose outcome may include stillbirths and enhanced cancer risks and susceptibility to HIV infection. Trichomonas vaginalis relies on imported purine and pyrimidine nucleosides and nucleobases for survival, since it lacks the enzymatic activities necessary for de novo biosynthesis. Here we show that T. vaginalis additionally lacks homologues of the bacterial or mammalian enzymes required for the synthesis of the nicotinamide ring, a crucial component in the redox cofactors NAD+ and NADP. Moreover, we show that a yet fully uncharacterized T. vaginalis protein homologous to bacterial and protozoan nucleoside hydrolases is active as a pyrimidine nucleosidase but shows the highest specificity toward the NAD+ metabolite nicotinamide riboside. Crystal structures of the trichomonal riboside hydrolase in different states reveals novel intermediates along the nucleoside hydrolase-catalyzed hydrolytic reaction, including an unexpected asymmetry in the homotetrameric assembly. The active site structure explains the broad specificity toward different ribosides and offers precise insights for the engineering of specific inhibitors that may simultaneously target different essential pathways in the parasite.

Vaginitis and risk of sexually transmitted infections: results of a multi-center U.S. clinical study using STI nucleic acid amplification testing.

Significant increases in rates of sexually transmitted infections (STIs) caused by Trichomonas vaginalis (TV), Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Mycoplasma genitalium (MG) are occurring in the United States. We present results of a U.S. study examining the intersection of STIs and vaginitis. Among 1,051 women with diagnoses for the presence or absence of bacterial vaginosis (BV) and/or symptomatic vulvovaginal candidiasis (VVC), 195 (18.5%) had one or more STIs, including 101 (9.6%) with TV, 24 (2.3%) with CT, 9 (0.8%) with NG, and 93 (8.8%) with MG. STI prevalence in BV-positive women was 26.3% (136/518), significantly higher than STI prevalence of 12.5% (59/474) in BV-negative women (P < 0.0002). Unlike infections with CT or NG, solo infections of MG or TV were each significantly associated with a diagnosis of BV-positive/VVC-negative (OR 3.0751; 95% CI 1.5797-5.9858, P = 0.0113, and OR 2.873; 95% CI 1.5687-5.2619, P = 0.0017, respectively) and with mixed infections containing MG and TV (OR 3.4886; 95% CI 1.8901-6.439, P = 0.0042, and OR 3.1858; 95% CI 1.809-5.6103, P = 0.0014, respectively). TV and MG infection rates were higher in all Nugent score (NS) categories than CT and NG infection rates; however, both STIs had similar comparative prevalence ratios to CT in NS 6-10 vs NS 0-5 (CT: 3.06% vs 1.4%, 2.2-fold; MG: 10.7% vs 6.1%, 1.8-fold; TV: 14.5% vs 7.0%, 2.1-fold). NG prevalence was relatively invariant by the NS category. These results highlight the complexity of associations of STIs with two major causes of vaginitis and underscore the importance of STI testing in women seeking care for abnormal vaginal discharge and inflammation. IMPORTANCE: This study reports high rates for sexually transmitted infections (STIs) in women seeking care for symptoms of vaginitis and bacterial vaginosis, revealing highly complex associations of STIs with two of the major causes of vaginal dysbiosis. These results underscore the importance of STI testing in women seeking care for abnormal vaginal discharge and inflammation.

Anal HPV prevalence in individuals with and without other concomitant sexually transmitted infections.

The association between human papillomavirus (HPV) and other sexually transmitted infections (STIs) in anal lesions still remains unclear. Aim of the study was to evaluate the prevalence of simultaneous infection of HPV and Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and Trichomonas vaginalis in individuals screened for HPV anal infection. A total of 507 anal samples were tested for both anal HPV and STIs: 16% resulted positive for one or more non-HPV STIs. Specifically, C. trachomatis, M. genitalium, and N. gonorrhoeae were detected in 8%, 5%, and 4% of cases, respectively. Two groups were considered, including a positive STI group and a negative STI group. The prevalence of HPV was similar in patients in both groups: high risk (HR)-HPV and low risk (LR)-HPV were 67% and 53% versus 62% (p = 0.361) and 54% (p = 0.864) of patients, respectively. However, HPV 16, 18, 35, 51, 59, and 69 were significantly more frequent in patients tested positive for other STIs versus HPV infection alone (p < 0.05). No significant differences between the two groups were observed in vaccination coverage, 28% versus 32% (p = 0.463), and HIV status, 86% versus 84% (p = 0.658). The study shows that the overall HPV status is not directly correlated to other STIs in the investigated population, except for certain HPV types, including HR-HPV 16, reinforcing the urge for a greater vaccination coverage.

Aetiological molecular identification of sexually transmitted infections that cause urethral discharge syndrome and genital ulcer disease in Brazilian men: a nationwide study.

BACKGROUND: Little is known about the aetiology of urethral discharge syndrome (UDS) and genital ulcer disease (GUD) in Brazil due to limited access to laboratory tests and treatment based mainly on the syndromic approach. OBJECTIVES: To update Brazilian treatment guidelines according to the current scenario, the first nationwide aetiological study for UDS and GUD was performed. METHODS: Male participants with urethral discharge (UD) and/or genital ulcer (GU) reports were enrolled. Sample collection was performed by 12 sentinel sites located in the five Brazilian regions. Between 2018 and 2020, 1141 UD and 208 GU samples were collected in a Universal Transport Medium-RT (Copan). A multiplex quantitative PCR kit (Seegene) was used to detect UD: Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), M. hominis (MH), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV), Ureaplasma parvum (UP), U. urealyticum (UU) and another kit to detect GU: cytomegalovirus (CMV), Haemophilus ducreyi (HD), herpes simplex virus type 1 (HSV1), herpes simplex virus type 2 (HSV2), lymphogranuloma venereum (LGV), Treponema pallidum (TP) and varicella-zoster virus (VZV). RESULTS: In UD samples, the frequency of pathogen detection was NG: 78.38%, CT: 25.6%, MG: 8.3%, UU: 10.4%, UP: 3.5%, MH: 3.5% and TV: 0.9%. Coinfection was assessed in 30.9% of samples, with 14.3% of NG/CT coinfection. The most frequent pathogen identified in GU was HSV2, present in 40.8% of the samples, followed by TP at 24.8%, LGV and CMV at 1%, and HSV1 at 0.4%. Coinfection of TP/HSV2 was detected in 4.4% of samples. VZV and HD were not detected. In 27.7% of the GU samples, no pathogen was detected. CONCLUSION: This study provided the acquisition of unprecedented data on the aetiology of UDS and GUD in Brazil, demonstrated the presence of a variety of pathogens in both sample types and reaffirmed the aetiologies known to be most prevalent globally.

Challenges in Male Partner Referral Among Trichomonas vaginalis -Infected Women.

ABSTRACT: This study assessed feasibility of male partner referral by Trichomonas vaginalis -infected women. Of 93 women approached, only 20 enrolled. Only 1 male partner contacted the study but was unable to be reached for scheduling. Other public health interventions are necessary to engaged T. vaginalis -infected women and their male partners in care.

Association Between Serum 25-Hydroxyvitamin D and Trichomonas vaginalis Infection Among American Adults: NHANES 2013-2016.

BACKGROUND: Previous studies have suggested that vitamin D may possess anti-infection properties, but the relationship between vitamin D and Trichomonas vaginalis infection remains unexplored. METHODS: Using data from the National Health and Nutrition Examination Survey between 2013 and 2016, we conducted multivariate regression analyses and subgroup analyses to investigate the association between 25-hydroxyvitamin D (25[OH]D) levels and T. vaginalis infection, ensuring the robustness of our results. RESULTS: The final sample included data from 4318 individuals aged 20 to 59 years, among which 92 were diagnosed with T. vaginalis infection. For every 10 nmol/L increase in serum 25(OH)D level, there was a 22% reduction in the likelihood of T. vaginalis infection incidence (adjusted odds ratio [aOR], 0.78; 95% confidence interval [CI], 0.69-0.90). Similarly, higher concentration tertiles demonstrated relatively lower infection ratios compared with the tertile with the lowest 25(OH)D concentration (aOR, 0.54 [95% CI, 0.30-0.95; P = 0.030] for T2; aOR, 0.23 [95% CI, 0.09-0.61; P < 0.001] for T3). CONCLUSIONS: Our cross-sectional study indicates a negative association between 25(OH)D levels and the prevalence of T. vaginalis infection. However, further high-quality evidence is needed to establish a causal relationship between 25(OH)D levels and T. vaginalis infection, as well as to evaluate the potential role of vitamin D supplementation in preventing T. vaginalis infection.

Clinical Evaluation of the Alinity m STI Multiplex PCR Assay.

BACKGROUND: Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) are routinely tested and reported; however, Trichomonas vaginalis (TV) is the most common sexually transmitted infection (STI) in the United States and the prevalence of Mycoplasma genitalium (MG) infections is likely higher than estimated. We examined the clinical performance of the Alinity m STI assay for detection and surveillance of CT/NG/TV/MG in urine specimens from patients at a large academic medical center. METHODS: Urine specimen from 198 patients was tested in this evaluation. Alinity m STI and Aptima Combo 2 CT/NG and TV assay (Panther System) results were compared, with discrepant results run on the cobas 6800 CT/NG, TV/MG assays. Analyzer turnaround times, time from loading the specimen on the analyzer to results reporting, were determined for Alinity m and Panther systems. RESULTS: Overall percent agreements of the Alinity m in comparison with the Aptima and cobas assays for CT, NG, TV, and MG were 99.5% (97.2%, 99.9%), 99.5% (97.2%, 99.9%), 98.4% (95.5%, 99.5%), and 86.4% (66.7%, 95.3), respectively. There were 5 discrepant samples (CT, 1; NG, 1; TV, 3) between the Alinity m and the Aptima assays, and 3 MG discrepant samples between the Alinity m STI and cobas 6800. Two of the 5 Aptima and Alinity m discrepant samples were resolved as they yielded similar results on both Alinity m and cobas 6800. TV and MG infections comprised 54% of the positive samples and were more often asymptomatic than CT and NG infections. Analyzer turnaround time was 3 hours 25 minutes for the Aptima CT/NG, 3 hours 25 minutes for Aptima TV, and 1 hour 55 minutes for Alinity m STI assay. CONCLUSIONS: The Alinity m STI assay allows for fast and simultaneous detection of the 4 major STI pathogens, which can facilitate surveillance and provide accurate results to help clinicians diagnose for initiation of appropriate treatment.

The Association Between Human Immunodeficiency Virus and Bacterial Vaginosis and Metronidazole Treatment Failure for Trichomonas vaginalis.

BACKGROUND: Trichomonas vaginalis (TV) is a common sexually transmitted infection. High rates of repeated infections have been observed, particularly among women living with human immunodeficiency virus (HIV). Trichomonas vaginalis frequently cooccurs with bacterial vaginosis (BV). The purpose of this study was to determine if coinfections with TV, BV, and HIV could lead to differential treatment failure outcomes. METHODS: Data were pooled from 2 prior randomized control trials comparing 2 g oral single-dose versus 500-mg twice daily oral 7-day dose metronidazole for the treatment of TV in HIV infected and HIV uninfected women. Trichomonas vaginalis rates 1-month postcompletion of treatment were compared by arm, HIV and BV status after removing those who had sexual reexposure, and/or did not complete their treatment. RESULTS: Data for 795 subjects were included in the study, of which 76 (9.6%) experienced treatment failure. In the final multivariable model, which included treatment dose, HIV status, and BV status, odds of treatment failure infection in the 7-day dose group were lower than the odds in the single dose group (odds ratio, 040; 95% confidence interval, 0.23-0.68). Treatment failure was lower in the multidose arm compared with single dose for both HIV-infected (4.0% vs 10.3%; P = 0.0568) and HIV-uninfected (7.3% vs 15.4%; P = 0.0037). Neither HIV nor BV was associated with higher treatment failure. CONCLUSIONS: Human immunodeficiency virus infection and BV status did not significantly alter the rate of repeat infection for either single dose or 7-day dose metronidazole. Among all women, 7-day metronidazole lowered the odds of treatment failure.

Reducing Barriers for Expedited Partner Treatment in Adolescents and Young Adults: A Quality Improvement Initiative.

BACKGROUND: Adolescents and young adults (AYAs) face significant barriers to screening, testing, and treatment of sexually transmitted infections (STIs). Expedited partner therapy (EPT) streamlines partner treatment of STIs, but use among adolescents is low. We aimed to increase EPT offering and provision at 2 adolescent medicine clinics (AMCs) and the emergency department (ED) in an urban children's hospital. We addressed barriers at provider, pharmacy, and patient levels. We compared EPT offering and provision for chlamydia ( Chlamydia trachomatis [CT]) and trichomonas ( Trichomonas vaginalis [TV]) infection at baseline and across 2 intervention cycles. METHODS: Baseline data were collected from July 2019 to March 2020 and our intervention time frame spanned from April 2020 to October 2021. Laboratory codes identified patients with CT or TV infections. Cycle 1 allowed providers to order EPT within a patient's chart. The second cycle targeted education and standardization for STI/EPT notification and counseling. During this cycle, notification of ED patients was centralized to the AMC nurses. RESULTS: A total of 747 CT and TV cases were identified. In the AMC, EPT offering increased from 77.3% to 87.7% ( P = 0.01). Expedited partner therapy provision increased from 32.3% to 69.9% ( P < 0.001). Expedited partner therapy offering for ED patients increased by 82.3%. Retesting rates remained consistent, with a significant drop in reinfection rates ( P = 0.003) within patients seen in the AMC. CONCLUSIONS: This quality improvement initiative successfully increased EPT offering and provision among the cases identified. Future cycles may include longer-term follow-up to confirm partner treatment and testing per guidelines.

Prospective Cohort Study of Treatment Outcomes of Vaginal Discharge Syndrome in Women in Windhoek, Namibia.

BACKGROUND: Syndromic treatment is the standard of care for vaginal discharge syndrome (VDS) in resource-constrained settings. However, the outcomes of VDS treatment have not been well documented. This study aimed to determine the incidence, risk factors, and microbial etiology of treatment failure in women with VDS. METHODS: This prospective cohort study of women with VDS was conducted between September 2021 and March 2022 at Katutura Intermediate Hospital in Windhoek, Namibia. Microbiological analyses of sexually transmitted infections (STIs; Chlamydia trachomatis , Neisseria gonorrhoeae , Trichomonas vaginalis , Mycoplasma genitalium ), bacterial vaginosis, and vulvovaginal candidiasis (VVC) were performed. Treatment outcomes were assessed at 7 and 30 days after treatment, followed by microbial investigation in case of treatment failure. RESULTS: One hundred nine women were enrolled, and 94 (86%) completed the follow-up. At baseline, 58 of 109 women (53%) were diagnosed with STI, 47 of 109 (43%) with bacterial vaginosis, and 45 of 109 (41%) with VVC. Candida albicans (33 of 45; 73%) was the main pathogen in VVC, with fluconazole resistance detected in 8 of 33 isolates (24%); 10 of 12 (80%) of non- albicans Candida species showed resistance. The incidence of treatment failure was 3.6 per 100 person-years at 7 days and 1.0 per 100 person-years at 30 days of follow-up; 17 of 94 women (18%) had recurrent VDS, and 12 of 94 women (13%) had persistent VDS. Vulvovaginal candidiasis (odds ratio, 4.3; 95% confidence interval, 1.7-11; P = 0.002) at baseline was associated with treatment failure. CONCLUSIONS: Treatment failure after syndromic management of VDS is common in resource-constrained settings. Access to diagnostic testing, including fungal culture and susceptibility testing, is recommended to improve outcomes.

Sandwich enzyme-linked aptamer-based assay for the detection of Trichomonas vaginalis.

Trichomoniasis is the most prevalent curable, non-viral sexually transmitted infection (STI), with an estimated 156 million new infections in 2020. It can potentially result in adverse birth outcomes as well as infertility in men, whilst it also increases the risk of acquiring HIV and contracting other vaginal infections. It is mostly prevalent among women in low-income countries and especially in Africa and the Americas. This STI is caused by Trichomonas vaginalis (TV) and a robust, cost-effective, sensitive, specific and rapid diagnostic test is urgently required. We report the screening of 6 full-length and 4 truncated aptamers previously selected in our group for use in a microplate-based sandwich assay. The combination of dual aptamers comprising a short 14-mer truncated capture aptamer (termed A1_14mer) and a full-length non-truncated reporter aptamer (A6) was elucidated to be the optimum pair for a sensitive sandwich enzyme-linked aptamer assay (ELAA) for the detection of TV achieving a detection limit of 3.02 × 104 TV cells/mL. The results obtained with the A1_14mer-A6 ELAA correlate excellently with wet-mount microscopy for the detection of TV in clinical specimens, cervicovaginal lavages and vaginal swabs, highlighting the potential clinical application of this assay for cost-effective population screening and subsequent prevention of the onset of complications associated with undiagnosed and untreated TV.

Complement receptor 3 is required for maximum in vitro trogocytic killing of the parasite Trichomonas vaginalis by human neutrophil-like cells.

Trichomonas vaginalis (Tv) is a parasite that causes trichomoniasis, a prevalent sexually-transmitted infection. Neutrophils are found at the site of infection, and can rapidly kill the parasite in vitro, using trogocytosis. However, the specific molecular players in neutrophil killing of Tv are unknown. Here, we show that complement proteins play a role in Tv killing by human neutrophil-like cells (NLCs). Using CRISPR/Cas9, we generated NLCs deficient in each of three complement receptors (CRs) known to be expressed on human neutrophils: CR1, CR3, and CR4. Using in vitro trogocytosis assays, we found that CR3, but not CR1 or CR4 is required for maximum trogocytosis of the parasite by NLCs, with NLCs lacking CR3 demonstrating ~40% reduction in trogocytosis, on average. We also observed a reduction in NLC killing of Tv in CR3 knockout, but not CR1 or CR4 knockout NLCs. On average, NLCs lacking CR3 had ~50% reduction in killing activity. We also used a parallel approach of pre-incubating NLCs with blocking antibodies against CR3, which similarly reduced NLC killing of parasites. These data support a model in which Tv is opsonized by the complement protein iC3b, and bound by neutrophil CR3 receptor, to facilitate trogocytic killing of the parasite.

Detection of Trichomonas vaginalis by Allplex™ STI Essential Assay (Seegene) in clinical samples from the Brazilian public health system users.

The failures in Trichomonas vaginalis (TV) infection diagnosis leave more than half of cases unidentified. In this report, urine and vaginal discharge samples were analyzed by wet mount, culture examination, and real-time PCR by Allplex™ (Seegene®) kit, in a population assisted by the Brazilian Public Health System. From 747 samples, 2.81% were positive for TV in wet mount and culture, and 3.88% by Allplex™. Samples kept at - 80 ºC for 22 months did not impair the PCR technique. The sensitivity for wet mount, culture, and Allplex™ was 72, 100, and 100%, respectively. Allplex™ technique showed highest detection of TV.

Trichomonas vaginalis: comparison of primers for implementation as an in-house PCR in rural Vellore, South India.

BACKGROUND: Trichomonas vaginalis (TV) accounts for the highest burden of curable, non-viral sexually transmitted infections worldwide. Prevalence in India ranges from 0.4 to 27.4% in women and 0.0-5.6% in men. In 2015, the prevalence of TV among pregnant women of rural Vellore was 3.11% using Sekisui OSOM® Trichomonas test and culture methods. Molecular methods are the most sensitive, rapid diagnostic tool for Sexually Transmitted Infection's (STI) albeit cost hinders implementation of commercial platforms. To determine a sensitive, sustainable molecular method, we compared three targets (Adhesin AP65, cytoskeleton Beta-tubulin BTUB 9/2 and TVK 3/7) with the highest published diagnostic accuracy against microscopy, culture and Real Time PCR (RT- PCR). MATERIALS & METHODS: Six-hundred adult, sexually active women attending the Obstetrics-Gynaecology rural out-patient clinic the Rural Unit for Health and Social Affairs (RUHSA) from July 2020 - February 2021 were enrolled. A vaginal lateral and posterior fornix specimen was inoculated, onsite, into Biomed InPouch® TV culture and smeared onto a slide for fluorescence microscopy using Acridine orange. A flocked nylon swab specimen for PCR was used to determine the sensitivities of the Adhesin AP65, cytoskeleton Beta-tubulin BTUB 9/2 and TVK 3/7 gene targets. Seegene Allplex™ STI Essential Assay, S.Korea was used to confirm TV positives. RESULTS: Nine specimens (9/600, 1.5%) were positive for TV. There was a 100% correlation between Biomed InPouch TV® culture, PCR with TVK 3/7 and RT-PCR while a correlation of 66.6% with BTUB 9/2 and AP65 gene targets. Clinically, 77.7% (n = 7) presented with white-greenish discharge per vagina, 11% (n = 1) with infertility, 22.2% (n = 2) were asymptomatic. Eight of nine patients (88.9%) had co-infections with other bacterial STIs. Prevalence of TV coinfection with Neisseria gonorrhoea was 1.1%. CONCLUSION: Current hospital-based prevalence of TV in rural Vellore was 1.5%. Repetitive DNA target TVK 3/7 was more sensitive than AP65 and BTUB 9/2 primers.