Gynaecological infections as risk determinants of subsequent cervical neoplasia

The Past, Present, and Future in the Diagnosis of a Neglected Sexually Transmitted Infection: Trichomoniasis

More than one million curable sexually transmitted infections occur every day. Trichomonas vaginalis is one of the main infections responsible for these epidemiological data; however, the diagnosis of this protozoan is still mainly based on microscopic and culture identification. The commercialization of immunological tests and the development of molecular techniques have improved the sensitivity of classical methods. Nevertheless, the fact that trichomoniasis is a neglected parasitic infection hinders the development of novel techniques and their implementation in routine diagnosis. This review article shows the different methods developed to identify T. vaginalis in population and the difficulties in diagnosing male and asymptomatic patients. The importance of including this parasite in routine gynecological screening, especially in pregnant women, and the importance of considering T. vaginalis as an indicator of high-risk sexual behavior are also discussed.

Trichomonas vaginalis Legumain-2, TvLEGU-2, Is an Immunogenic Cysteine Peptidase Expressed during Trichomonal Infection

Trichomonas vaginalis is the causative agent of trichomoniasis, the most prevalent nonviral, neglected sexually transmitted disease worldwide. T. vaginalis has one of the largest degradomes among unicellular parasites. Cysteine peptidases (CPs) are the most abundant peptidases, constituting 50% of the degradome. Some CPs are virulence factors recognized by antibodies in trichomoniasis patient sera, and a few are found in vaginal secretions that show fluctuations in glucose concentrations during infection. The CPs of clan CD in T. vaginalis include 10 genes encoding legumain-like peptidases of the C13 family. TvLEGU-2 is one of them and has been identified in multiple proteomes, including the immunoproteome obtained with Tv (+) patient sera. Thus, our goals were to assess the effect of glucose on TvLEGU-2 expression, localization, and in vitro secretion and determine whether TvLEGU-2 is expressed during trichomonal infection. We performed qRT-PCR assays using parasites grown under different glucose conditions. We also generated a specific anti-TvLEGU-2 antibody against a synthetic peptide of the most divergent region of this CP and used it in Western blot (WB) and immunolocalization assays. Additionally, we cloned and expressed the tvlegu-2 gene (TVAG_385340), purified the recombinant TvLEGU-2 protein, and used it as an antigen for immunogenicity assays to test human sera from patients with vaginitis. Our results show that glucose does not affect tvlegu-2 expression but does affect localization in different parasite organelles, such as the plasma membrane, Golgi complex, hydrogenosomes, lysosomes, and secretion vesicles. TvLEGU-2 is secreted in vitro, is present in vaginal secretions, and is immunogenic in sera from Tv (+) patients, suggesting its relevance during trichomonal infection.

Cervical precancer and cancer incidence among insured women with and without HIV in South Africa

HIV infection increases the risk of developing cervical cancer; however, longitudinal studies in sub-Saharan Africa comparing cervical cancer rates between women living with HIV (WLWH) and women without HIV are scarce. To address this gap, we compared cervical precancer and cancer incidence rates between WLWH and women without HIV in South Africa using reimbursement claims data from a medical insurance scheme from January 2011 to June 2020. We used Royston-Parmar flexible parametric survival models to estimate cervical precancer and cancer incidence rates as a continuous function of age, stratified by HIV status. Our study population consisted of 518 048 women, with exclusions based on the endpoint of interest. To analyse cervical cancer incidence, we included 517 312 women, of whom 564 developed cervical cancer. WLWH had an ~3-fold higher risk of developing cervical precancer and cancer than women without HIV (adjusted hazard ratio for cervical cancer: 2.99; 95% confidence interval [CI]: 2.40-3.73). For all endpoints of interest, the estimated incidence rates were higher in WLWH than women without HIV. Cervical cancer rates among WLWH increased at early ages and peaked at 49 years (122/100 000 person-years; 95% CI: 100-147), whereas, in women without HIV, incidence rates peaked at 56 years (40/100 000 person-years; 95% CI: 36-45). Cervical precancer rates peaked in women in their 30s. Analyses of age-specific cervical cancer rates by HIV status are essential to inform the design of targeted cervical cancer prevention policies in Southern Africa and other regions with a double burden of HIV and cervical cancer.

A microfluidic-chip-based system with loop-mediated isothermal amplification for rapid and parallel detection of Trichomonas vaginalis and human papillomavirus

Cervical cancer is a significant global health issue primarily caused by high-risk types of human papillomavirus (HPV). Recent studies have reported an association between Trichomonas vaginalis (T. vaginalis) infections and HPV infections, highlighting the importance of simultaneously detecting these pathogens for effective cervical cancer risk management. However, current methods for detecting both T. vaginalis and HPV are limited. In this study, we present a novel approach using a microfluidic-chip-based system with loop-mediated isothermal amplification (LAMP) for the rapid and parallel detection of T. vaginalis, HPV16, HPV18, and HPV52 in a reagent-efficient and user-friendly manner. Compared to conventional LAMP assays in tubes, our system exhibits enhanced sensitivity with values of 2.43 × 101, 3.00 × 102, 3.57 × 101, and 3.60 × 102 copies per reaction for T. vaginalis, HPV16, HPV18, and HPV52, respectively. Additionally, we validated the performance of our chip by testing 47 clinical samples, yielding results consistent with the diagnostic methods used by the hospital. Therefore, our system not only offers a promising solution for concurrent diagnosis of T. vaginalis and HPV infections, particularly in resource-limited areas, due to its cost-effectiveness, ease of use, and rapid and accurate detection performance, but can also contribute to future research on the co-infection of these two pathogens. Moreover, the system possesses the capability to simultaneously detect up to 22 different types of pathogens, making it applicable across a wide range of domains such as diagnostics, food safety, and water monitoring.

The correlation between Trichomonas vaginalis infection and reproductive system cancer: a systematic review and meta-analysis

BACKGROUND

Trichomonas vaginalis (T. vaginalis) is a microaerophilic protozoan parasite which is responsible for trichomoniasis, the most common non-viral sexually transmitted infection in the world. The infection greatly damages the reproductive system. However, whether T. vaginalis infection can cause reproductive system cancer remains controversial.

METHODS

This study systematically searched PubMed, EMBASE, Ovid and Google scholar, and 144 relevant articles were retrieved and classified into three categories: epidemiological investigations (68), reviews (30) and research articles (46). These three types of articles were verified according to their respective inclusion and exclusion criteria. Stata 16 was used to conduct a meta-analysis on the articles of epidemiological investigations for analysing the correlation between T. vaginalis infection and reproductive system cancer.

RESULTS

The result of meta-analysis indicated that the rate of T. vaginalis infection in the cancer group was significantly higher than that in the non-cancer group (OR = 1.87, 95% CI 1.29-2.71, I² = 52%). Moreover, the cancer rate of the population infected with T. vaginalis was significantly higher than that of the population without T. vaginalis infection (OR = 2.77, 95% CI 2.37-3.25, I² = 31%). The review articles and most research articles stated that the infection of T. vaginalis could lead to cancer and the pathogenic mechanisms were as follows: T. vaginalis promoting inflammatory response, T. vaginalis infection changing the internal environment around parasitic sites and signal transduction pathway, the metabolites secreted by T. vaginalis inducing carcinogenesis and T. vaginalis increasing other pathogenic microbial infection to promote the occurrence of cancer.

CONCLUSIONS

Our study confirmed that there was a correlation between the infection of T. vaginalis and reproductive system cancer, and provided some possible research directions for clarifying the carcinogenic mechanisms caused by T. vaginalis infection.

Distinct features of the host-parasite interactions between nonadherent and adherent Trichomonas vaginalis isolates

Cytoadherence of Trichomonas vaginalis to human vaginal epithelial cells (hVECs) was previously shown to involve surface lipoglycans and several reputed adhesins on the parasite. Herein, we report some new observations on the host-parasite interactions of adherent versus nonadherent T. vaginalis isolates to hVECs. The binding of the TH17 adherent isolate to hVECs exhibited an initial discrete phase followed by an aggregation phase inhibited by lactose. T. vaginalis infection immediately induced surface expression of galectin-1 and -3, with extracellular amounts in the spent medium initially decreasing and then increasing thereafter over the next 60 min. Extracellular galectin-1 and -3 were detected on the parasite surface but only the TH17 adherent isolate could uptake galectin-3 via the lysosomes. Only the adherent isolate could morphologically transform from the round-up flagellate with numerous transient protrusions into a flat amoeboid form on contact with the solid surface. Cytochalasin D challenge revealed that actin organization was essential to parasite morphogenesis and cytoadherence. Real-time microscopy showed that parasite exploring and anchoring on hVECs via the axostyle may be required for initial cytoadherence. Together, the parasite cytoskeleton behaviors may collaborate with cell surface adhesion molecules for cytoadherence. The nonadherent isolate migrated faster than the adherent isolate, with motility transiently increasing in the presence of hVECs. Meanwhile, differential histone acetylation was detected between the two isolates. Also, TH17 without Mycoplasma symbiosis suggests that symbiont might not determine TH17 innate cytoadherence. Our findings regarding distinctive host-parasite interactions of the isolates may provide novel insights into T. vaginalis infection.

Prevalence of Trichomonas vaginalis by polymerase chain reaction-based molecular method among symptomatic women from Northern India

Introduction

Trichomoniasis remains one of the most common sexually transmitted infections, which is curable. To prevent complications and transmission, prompt and correct diagnosis is essential to treat Trichomonas vaginalis. The present study was done to evaluate polymerase chain reaction (PCR) with other conventional techniques for the diagnosis of T. vaginalis infection and determine the prevalence of T. vaginalis in women with vaginal discharge based on PCR assay.

Methods

Vaginal swabs were collected by the trained health-care professional using FLOQSwabs™ (Copan, Italy) during routine pelvic examinations among 1974 symptomatic females. The wet microscopy, culture, and PCR were performed.

Results

The sensitivity of wet mount and culture in comparison to PCR was 60.87% and 56.52%, respectively. The kappa inter-rater agreement of T. vaginalis PCR showed substantial agreement with wet mount microscopy (κ = 0.742) and culture (κ = 0.707). The PCR detected an additional 17 cases that were missed by conventional techniques.

Discussion

The study highlights the importance of PCR for T. vaginalis screening among symptomatic females.

Diagnosis and Management of Trichomonas vaginalis: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

Trichomonas vaginalis is likely the most prevalent nonviral sexually transmitted infection, affecting an estimated 3.7 million women and men in the United States. Health disparities are prominent in the epidemiology of trichomoniasis, as African Americans are >4 times more likely to be infected than persons of other races. Since publication of the 2015 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines, additional data have bolstered the importance of T. vaginalis infection sequelae in women, including increased risk of human immunodeficiency virus (HIV) acquisition, cervical cancer, preterm birth, and other adverse pregnancy outcomes. Less is known about the clinical significance of infection in men. Newly available diagnostic methods, including point-of-care assays and multiple nucleic acid amplification tests, can be performed on a variety of genital specimens in women and men, including urine, allowing more accurate and convenient testing and screening of those at risk for infection. Repeat and persistent infections are common in women; thus, rescreening at 3 months after treatment is recommended. In vitro antibiotic resistance to 5-nitroimidazole in T. vaginalis remains low (4.3%) but should be monitored. High rates of T. vaginalis among sexual partners of infected persons suggest a role for expedited partner treatment. A randomized controlled trial in HIV-uninfected women demonstrated that multidose metronidazole 500 mg twice daily for 7 days reduced the proportion of women with Trichomonas infection at 1 month test of cure compared with women receiving single-dose therapy (2 g). The 2-g single-dose oral metronidazole regimen remains the preferred treatment in men.

Galectins as potential therapeutic targets in STIs in the female genital tract

Every day, more than one million people worldwide acquire a sexually transmitted infection (STI). This public health problem has a direct effect on women's reproductive and sexual health as STIs can cause irreversible damage to fertility and can have negative consequences associated with discrimination and social exclusion. Infection with one sexually transmitted pathogen predisposes to co-infection with others, suggesting the existence of shared pathways that serve as molecular links between these diseases. Galectins, a family of β-galactoside-binding proteins, have emerged as endogenous mediators that facilitate cell-surface binding, internalization and cell invasion of many sexually transmitted pathogens, including Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, Candida albicans, HIV and herpes simplex virus. The ability of certain galectins to dimerize or form multimeric complexes confers the capacity to interact simultaneously with glycosylated ligands on both the pathogen and the cervico-vaginal tissue on these proteins. Galectins can act as a bridge by engaging glycans from the pathogen surface and glycosylated receptors from host cells, which is a mechanism that has been shown to be shared by several sexually transmitted pathogens. In the case of viruses and obligate intracellular bacteria, binding to the cell surface promotes pathogen internalization and cell invasion. Inflammatory responses that occur in cervico-vaginal tissue might trigger secretion of galectins, which in turn control the establishment, evolution and severity of STIs. Thus, galectin-targeted therapies could potentially prevent or decrease STIs caused by a diverse array of pathogenic microorganisms; furthermore, anti-galectin agents might reduce treatment costs of STIs and reach the most vulnerable populations.

Protozoan-Viral-Bacterial Co-Infections Alter Galectin Levels and Associated Immunity Mediators in the Female Genital Tract

Co-infections with sexually transmittable pathogens are common and more likely in women with disturbed vaginal bacteriome. Among those pathogens, the protozoan parasite Trichomonas vaginalis (TV) is most common after accounting for the highly persistent DNA viruses human papillomavirus (HPV) and genital herpes. The parasitic infection often concurs with the dysbiotic syndrome diagnosed as bacterial vaginosis (BV) and both are associated with risks of superimposed viral infections. Yet, the mechanisms of microbial synergisms in evading host immunity remain elusive. We present clinical and experimental evidence for a new role of galectins, glycan-sensing family of proteins, in mixed infections. We assessed participants of the HIV Epidemiology Research Study (HERS) at each of their incident TV visits (223 case visits) matched to controls who remained TV-negative throughout the study. Matching criteria included age, race, BV (by Nugent score), HIV status, hysterectomy, and contraceptive use. Non-matched variables included BV status at 6 months before the matched visit, and variables examined at baseline, within 6 months of and/or at the matched visit e.g. HSV-2, HPV, and relevant laboratory and socio-demographic parameters. Conditional logistic regression models using generalized estimating equations calculated odds ratios (OR) for incident TV occurrence with each log₁₀ unit higher cervicovaginal concentration of galectins and cytokines. Incident TV was associated with higher levels of galectin-1, galectin-9, IL-1β and chemokines (ORs 1.53 to 2.91, p <0.001). Galectin-9, IL-1β and chemokines were up and galectin-3 down in TV cases with BV or intermediate Nugent versus normal Nugent scores (p <0.001). Galectin-9, IL-1β and chemokines were up in TV-HIV and down in TV-HPV co-infections. In-vitro, TV synergized with its endosymbiont Trichomonasvirus (TVV) and BV bacteria to upregulate galectin-1, galectin-9, and inflammatory cytokines. The BV-bacterium Prevotella bivia alone and together with TV downregulated galectin-3 and synergistically upregulated galectin-1, galectin-9 and IL-1β, mirroring the clinical findings of mixed TV–BV infections. P. bivia also downregulated TVV+TV-induced anti-viral response e.g. IP-10 and RANTES, providing a mechanism for conducing viral persistence in TV-BV co-infections. Collectively, the experimental and clinical data suggest that galectin-mediated immunity may be dysregulated and exploited by viral–protozoan–bacterial synergisms exacerbating inflammatory complications from dysbiosis and sexually transmitted infections.

Promising hit compounds against resistant trichomoniasis: Synthesis and antiparasitic activity of 3-(ω-aminoalkoxy)-1-benzyl-5-nitroindazoles

A series of 11 3-(ω-aminoalkoxy)-1-benzyl-5-nitroindazoles (2-12) has been prepared starting from 1-benzyl-5-nitroindazol-3-ol 13, and evaluated against sensitive and resistant isolates of the sexually transmitted protozoan Trichomonas vaginalis. Compounds 2, 3, 6, 9, 10 and 11 showed trichomonacidal profiles with IC₅₀ < 20 µM against the metronidazole-sensitive isolate. Moreover, all these compounds submitted to cytotoxicity assays against mammalian cells exhibited low non-specific cytotoxic effects, except compounds 3 and 9 which displayed moderate cytotoxicity (CC₅₀ = 74.7 and 59.1 µM, respectively). Those compounds with trichomonacidal effect were also evaluated against a metronidazole-resistant culture. Special mention deserve compounds 6 and 10, which displayed better IC₅₀ values (1.3 and 0.5 µM respectively) than that of the reference drug (IC₅₀ MTZ = 3.0 µM). The high activity of these compounds against the resistant isolate reinforces the absence of cross-resistance with the reference drug. The remarkable trichomonacidal results against resistant T. vaginalis isolates suggest the interest of 3-(ω-aminoalkoxy)-1-benzyl-5-nitroindazoles to be considered as good prototypes to continue in the development of new drugs with enhanced trichomonacidal activity, aiming to increase the non-existent drugs to face clinical resistance efficiently for those patients in whom therapy with 5-nitroimidazoles is contraindicated.

A hospital-based study on the prevalence of trichomoniasis and evaluation of accuracy of various diagnostic techniques

Background:

The sexually transmitted infections (STIs) caused by Trichomonas vaginalis have been associated with adverse pregnancy outcomes and increased risk of HIV transmission. Trichomoniasis remains underreported despite being easy to diagnose and treat. Moreover, availability of battery of diagnostic tools causes dilemma on the most appropriate techniques to be used.

Aims and Objectives:

The purpose of this study was to determine the prevalence of T. vaginalis and its diagnostic accuracy employing various diagnostic techniques in women presenting with vaginal discharge in gynecological outpatient department (GOPD) of our tertiary care hospital.

Materials and Methods:

Five vaginal swabs were collected from 204 patients with symptomatic vaginal discharge attending GOPD. Wet mount microscopy, Giemsa and acridine orange staining, culture in Kupferberg media and InPouch™ TV culture system, and polymerase chain reaction (PCR) were performed and compared.

Results:

The prevalence of T. vaginalis was 1.96% in the present study. Wet mount microscopy, staining method, and culture detected 1.96% of cases, whereas PCR detected 2.45% of cases.

Conclusion:

The prevalence of T. vaginalis was <3% among symptomatic vaginal discharge patients from GOPD. Although PCR had a higher detection rate, there was no significant difference in sensitivity and specificity between other diagnostic methods (direct wet mount, Giemsa/acridine orange staining, and InPouch™ TV culture system). Hence, the availability in a particular setting would determine the methods of choice to be used for the diagnosis of T. vaginalis.

Association Between Common Vaginal Infections and Cervical Non-Human Papillomavirus (HPV) 16/18 Infection in HPV-Vaccinated Women

BACKGROUND

How vaginal infections such as bacterial vaginosis, Candida spp, and Trichomonas vaginalis affect persistence of human papillomavirus (HPV) infection is not well established. Our study aimed to evaluate the association between common vaginal infections and cervical non-HPV16/18 infection, as risk factors associated with persistence of nonvaccine HPV types will become increasingly relevant in the setting of HPV vaccination.

METHODS

We performed an analysis in 2039 AS04-HPV16/18-vaccinated women enrolled in a phase II/III trial in China, who were HPV DNA negative at month 0 and 6 and had at least 1 subsequent follow-up visit. Vaginal infections were detected in liquid-based cytology according to the diagnostic criteria of the Bethesda System. Associations between vaginal infections and incident and 6-month persistent non-HPV16/18 infections in the cervix were evaluated using generalized estimating equations, adjusting for the age at initial vaccination, as well as HPV types in the persistence analysis.

RESULTS

Study visits with any vaginal infection had a statistically significant increased risk of incident non-HPV16/18 infection compared to those without vaginal infections (odds ratio [OR], 1.44 [95% confidence interval {CI}, 1.09-1.92]). However, vaginal infections were not associated with 6-month persistent non-HPV16/18 infection (OR, 1.02 [95% CI, .62-1.69]).

CONCLUSIONS

Our study suggests that common vaginal infections are not associated with persistence of non-HPV16/18 infection among HPV16/18-vaccinated women.

Trichomoniasis in a tertiary hospital of Madrid, Spain (2013-2017): prevalence and pregnancy rate, coinfections, metronidazole resistance, and endosymbiosis

Trichomoniasis is the most prevalent curable sexually transmitted infection (STI) worldwide and a risk factor for the acquisition of other STIs and adverse pregnancy outcomes. The objectives of this study were to determine the prevalence of T. vaginalis and related coinfections in women attending a third-level hospital of Madrid (Spain). A retrospective study of 24,173 vaginal exudates from women with suspected vaginitis was conducted between 2013 and 2017. Likewise, among T. vaginalis positive samples, co-occurrence with gonorrhea, chlamydia, syphilis, VIH, Mycoplasma hominis, and Ureaplasma urealyticum was checked. Moreover, seven T. vaginalis isolates from 2017 were randomly collected for endobionts, drug resistance, and microsatellite (MS) instability determinations. The prevalence of T. vaginalis was 0.8% between 2013 and 2017. Less than 20% of patients with trichomoniasis were submitted to a complete screening for other genital pathogens. From that, two patients were coinfected with chlamydia and three with syphilis. Surprisingly, 6.4% of positive samples were diagnosed among pregnant women, showing an alarming increase from 3.2% (2014) to 10% (2017). Among the isolates randomly analyzed, five carried T. vaginalis virus, five harbored mycoplasmas, and one was metronidazole-resistant. The molecular genotyping showed a high variability in the three MS evaluated. To our knowledge, this is the first study in Spain that evaluates the prevalence of trichomoniasis in general and pregnant population and includes biomolecular determinations. These results warn about the increasing prevalence and highlight the importance of including T. vaginalis detection in routine gynecological revisions with special emphasis on childbearing age women and patients with previous STIs.

Recent Advances in the Discovery of Novel Antiprotozoal Agents

Parasitic diseases have serious health, social, and economic impacts, especially in the tropical regions of the world. Diseases caused by protozoan parasites are responsible for considerable mortality and morbidity, affecting more than 500 million people worldwide. Globally, the burden of protozoan diseases is increasing and is been exacerbated because of a lack of effective medication due to the drug resistance and toxicity of current antiprotozoal agents. These limitations have prompted many researchers to search for new drugs against protozoan parasites. In this review, we have compiled the latest information (2012-2017) on the structures and pharmacological activities of newly developed organic compounds against five major protozoan diseases, giardiasis, leishmaniasis, malaria, trichomoniasis, and trypanosomiasis, with the aim of showing recent advances in the discovery of new antiprotozoal drugs.

Atypical cervical cytomorphologic predictors: a descriptive study of pre-cervical cancer patients of low education in Kenya

INTRODUCTION

high risk HPV is the perpetrator of cervical cancer disease, however screening and vaccination is not included in cervical cancer prevention program within public hospitals in Kenya. This descriptive study assessed the association of specific microbial STI and socio-demographic characteristics and practices with cervical cytomorphologic presentations in regards to pre cervical cancer grades amongst health seeking patients attending the reproductive health clinic of Nakuru County referral hospital, a public hospital under newly devolved health services governance.

METHODS

a total of 142 patients (AGC/AIS, n=8; HSIL, n=59; LSIL, n=35; controls, n=40) whose median age ranged between 20-70 years were purposively sampled. A structured questionnaire with closed and open ended entries was administered and STI screening including Pap smear examination for cytomorphological profiling done according to revised 2014 Bethesda classification. Associations were established using chi-square and multivariate logistic regression model to determine prediction of cervical atypia manifestations.

RESULTS

a majority of the study participants had only primary education or no education in AGC/AIS (63%) and HSIL (73%) relative to LSIL (49%) and controls (53%) (P=0.017). Koilocyte rates were higher in AGC/AIS (25%), HSIL (52%) and LSIL (77%) compared controls (12.5%) (P<0.0001). ASCUS predominated in HSIL (61%) and LSIL (86%), while almost all AGC/AIS had AGCUS (88%). HR HPV 16/18 infection rates were higher in AGC/AIS (100%), HSIL (80%) and LSIL (83%) relative to controls (10%) (P<0.0001), and was associated with higher risk of having AGC/AIS (OR, 2.0; 95% CI, 1.940-1.947; P<0.0001); HSIL, (OR, 36.3; 95% CI, 9.5-139.5; P<0.0001); and LSIL (OR, 50.1; 95% CI, 12.0-209.0; P<0.0001).

CONCLUSION

altogether, pre-cervical cancer in Kenyan women is characterized by koilocytosis and ASCUS probably from the high rates of HPV 16/18 infections. Promoting cancer education and screening for high risk HPV infections and pre-cancerous lesions will improve women's reproductive health.

Genetic Diversity of Trichomonas Vaginalis Clinical Isolates According to Restriction Fragment Length Polymorphism Analysis of the 60-kDa Proteinase Gene

INTRODUCCTION

Trichomonas vaginalis is a highly prevalent parasitic that causes the sexually transmitted disease trichomoniasis with some serious health complications. More understanding about genetic features of the parasite can be helpful in the study of the pathogenesis, epidemiology of the infection and drug susceptibility. For this end, we conducted analysis of a fragment (23 kDa) of the p60 of T. vaginalis gene.

MATERIAL AND METHODS

The restriction fragment length polymorphism (RFLP) methods was used.

RESULT AND DISCUSSION

RFLP analysis showed the difference between T. vaginalis isolates from symptomatic and asymptomatic patients, suggesting a relation between the genetic identity of the isolates and their clinical manifestations.

Anti-Trichomonas vaginalis activity of chalcone and amino-analogues

Trichomoniasis is the most common non-viral sexually transmitted disease worldwide and can lead to serious consequences in reproductive health, cancer, and HIV acquisition. The current approved treatment present adverse effects and drug resistance data on this neglected parasitic infection is underestimated. Chalcones are a family of molecules that present biological applications, such as activity against many pathogenic organisms including protozoan pathogens. Chalcone (1) and three amino-analogues (2-4) were synthesized by Claisen-Schmidt condensation reaction and had their activity evaluated against the parasitic protozoan Trichomonas vaginalis. This bioassay indicated the presence and position of the amino group on ring A was crucial for anti-T. vaginalis activity. Among these, 3'-aminochalcone (3) presented the most potent effect and showed high cytotoxicity against human vaginal cells. On the other hand, 3 was not able to exhibit toxicity against Galleria mellonella larvae, as well as the hemolytic effect on human erythrocytes. Trophozoites of T. vaginalis were treated with 3, and did not present significant reactive oxygen species (ROS) accumulation, but induced a significantly higher ROS accumulation in human neutrophils after co-incubation. T. vaginalis pyruvate:ferredoxin oxidoreductase (PFOR) and β-tubulin gene expression was not affected by 3.

Chemotherapeutic options for the treatment of human trichomoniasis

Trichomonas vaginalis is the causative agent of the most common non-viral sexually transmitted disease worldwide. The infection may be associated with severe complications, including infertility, preterm labour, cancer and an increased risk of human immunodeficiency virus (HIV) transmission. Treatment remains almost exclusively based on 5-nitroimidazoles, but resistance is on the rise. This article provides an overview of clinically evaluated systemic and topical treatment options for human trichomoniasis and summarises the current state of knowledge on various herbal, semisynthetic and synthetic compounds evaluated for their anti-Trichomonas efficacy in vitro.

Anti-Trichomonas vaginalis activity of ursolic acid derivative: a promising alternative

Trichomonas vaginalis is an extracellular parasite that binds to the epithelium of the human urogenital tract and causes the sexually transmitted infection, trichomoniasis. In view of increased resistance to drugs belonging to the 5-nitroimidazole class, new treatment alternatives are urgently needed. In this study, eight semisynthetized triterpene derivatives were evaluated for in vitro anti-T. vaginalis activity. Ursolic acid and its derivative, 3-oxime-urs-12-en-28-oic-ursolic acid (9), presented the best anti-T. vaginalis activity when compared to other derivatives, with minimum inhibitory concentration (MIC) at 25 μM. Moreover, 9 was active against several T. vaginalis fresh clinical isolates. Hemolysis assay demonstrated that 9 presented a low hemolytic effect. Importantly, 25 μM 9 was not cytotoxic against the Vero cell lineage. Finally, we demonstrated that compound 9 acts synergistically with metronidazole against a T. vaginalis metronidazole-resistant isolate. This report reveals the high potential of the triterpenoid derivative 9 as trichomonicidal agent.

Trichomonas vaginalis Induces Production of Proinflammatory Cytokines in Mouse Macrophages Through Activation of MAPK and NF-κB Pathways Partially Mediated by TLR2

Trichomoniasis, caused by Trichomonas vaginalis infection, is the most prevalent sexually transmitted disease in female and male globally. However, the mechanisms by innate immunity against T. vaginalis infection have not been fully elucidated. Toll-like receptor2 (TLR2) has been shown to be involved in pathogen recognition, innate immunity activation, and inflammatory response to the pathogens. Nonetheless, the function of TLR2 against T. vaginalis remains unclear. In the present study, we investigated the role of TLR2 in mouse macrophages against T. vaginalis. RT-qPCR analysis revealed that T. vaginalis stimulation increased the gene expression of TLR2 in wild-type (WT) mouse macrophages. T. vaginalis also induced the secretion of IL-6, TNF-α, and IFN-γ in WT mouse macrophages, and the expression of these cytokines significantly decreased in TLR^2-/- mouse macrophages and in WT mouse macrophages pretreated with MAPK inhibitors SB203580 (p38) and PD98059 (ERK). Western blot analysis demonstrated that T. vaginalis stimulation induced the activation of p38, ERK, and p65 NF-κB signal pathways in WT mouse macrophages, and the phosphorylation of p38, ERK, and p65 NF-κB significantly decreased in TLR2^-/- mouse macrophages. Taken together, our data suggested that T. vaginalis may regulates proinflammatory cytokines production by activation of p38, ERK, and NF-κB p65 signal pathways via TLR2 in mouse macrophages. TLR2 might be involved in the defense and elimination of T. vaginalis infection.

Proteomic profile approach of effect of putrescine depletion over Trichomonas vaginalis

Infection with Trichomonas vaginalis produces a malodorous seropurulent vaginal discharge due to several chemicals, including polyamines. The presence of 1,4-diamino-2-butanone (DAB) reduces the amount of intracellular putrescine by 90%, preventing the cotransport of exogenous spermine. DAB-treated parasites present morphological changes, which are restored by adding exogenous putrescine into the culture medium. However, the effect of polyamines over the trichomonad proteomic profile is unknown. In this study, we used a proteomic approach to analyze the polyamine-depletion and restoration effect by exogenous putrescine on T. vaginalis proteome. In the presence of inhibitor DAB, we obtained 369 spots in polyamine-depleted condition and observed 499 spots in the normal culture media. With DAB treatment, the intensity of 43 spots was increased but was found to be reduced in 39 spots, as compared to normal conditions. Interestingly, in DAB-treated parasites restored with a medium with added exogenous putrescine, 472 spots were found, of which 33 were upregulated and 63 were downregulated in protein intensity. Some of these downregulated proteins in DAB-treated parasites are involved in several cellular pathways such as glycolysis, glycolytic fermentation, arginine dihydrolase pathway, redox homeostasis, host cell binding mediated by carbohydrate, chaperone function, and cytoskeletal remodeling. Interestingly, the intensity of some of the proteins was restored by adding exogenous putrescine. In conclusion, the presence of DAB altered the proteomic profile of T. vaginalis, resulting in a decrease in the intensity of 130 proteins and an increase in the intensity of 43 proteins that was restored by the addition of putrescine.

Risk of high-risk human papillomavirus infection and cervical precancerous lesions with past or current trichomonas infection: a pooled analysis of 25,054 women in rural China

BACKGROUND

Trichomonas vaginitis (TV) infection has obviously been implicated in gynecological morbidity but still unclear in cervical lesions.

OBJECTIVE

To evaluate the risk of hr-HPV infection and cervical intraepithelial neoplasia grade 2 or worse (CIN2 + ) by TV infection.

STUDY DESIGN

The pooled study was conducted among 12 population-based, cervical cancer screening studies throughout China (N = 24,054). HPV was detected by Hybrid Capture^®2 (HC2) test. Past TV infection was measured by self-reporting, current TV infection was diagnosed by liquid-based cytology (LBC), cervical lesions was diagnosed by histopathology.

RESULTS

Respective prevalence of hr-HPV and CIN2+ were 17.4% and 3.3%. Out of 24,054 women, 14.6% reported past TV infection, and out of 11,853 women, 9.9% had current TV infection. Current TV-positive women had an increased risk for hr-HPV (OR 1.31, 95%CI: 1.11-1.56). The risk of CIN2+ decreased for hr-HPV positive women with current TV infection (adjusted OR 0.50, 95% CI: 0.30-0.84) and past TV infection (adjusted OR 0.68, 95% CI: 0.54-0.86). Among hr-HPV negative women, no significant associations were observed between past or current TV infection and risk of CIN2+.

CONCLUSIONS

Women infected with HPV are more likely to be infected by other types of sexually transmitted diseases. Current TV-positive women had an increased risk for hr-HPV infection compared to currently TV-negative women. Both past and current TV-positive women had a decreased risk for CIN2+, especially among high-risk HPV positive women. More direct investigation into the interaction between TV, HPV, inflammatory signals, and risk of carcinogenesis are further needed.

Strategies for Prevention and Treatment of Trichomonas vaginalis Infections

The last estimated annual incidence of Trichomonas vaginalis worldwide exceeds that of chlamydia and gonorrhea combined. This critical review updates the state of the art on advances in T. vaginalis diagnostics and strategies for treatment and prevention of trichomoniasis. In particular, new data on treatment outcomes for topical administration of formulations are reviewed and discussed.

Trichomonas vaginalis clinical isolates: cytoadherence and adherence to polystyrene, intrauterine device, and vaginal ring

The parasitism by Trichomonas vaginalis is complex and in part is mediated by cytoadherence accomplished via five surface proteins named adhesins and a glycoconjugate called lipophosphoglycan (TvLPG). In this study, we evaluated the ability of T. vaginalis isolates to adhere to cells, plastic (polystyrene microplates), intrauterine device (IUD), and vaginal ring. Of 32 T. vaginalis isolates, 4 (12.5%) were strong adherent. The T. vaginalis isolates TV-LACM6 and TV-LACM14 (strong polystyrene-adherent) were also able to adhere to IUD and vaginal ring. Following chemical treatments, results demonstrated that the T. vaginalis components, lipophosphoglycan, cytoskeletal proteins, and surface molecules, were involved in both adherence to polystyrene and cytoadherence. The gene expression level from four adhesion proteins was highest in trophozoites adhered to cells than trophozoites adhered to the abiotic surface (polystyrene microplate). Our data indicate the major involvement of TvLPG in adherence to polystyrene, and that adhesins are important for cytoadherence. Furthermore, to our knowledge, this is the first report showing the T. vaginalis adherence to contraceptive devices, reaffirming its importance as pathogen among women in reproductive age.

Diamine derivative anti-Trichomonas vaginalis and anti-Tritrichomonas foetus activities by effect on polyamine metabolism

Human and bovine trichomoniasis are sexually transmitted diseases (STD) caused by Trichomonas vaginalis and Tritrichomonas foetus, respectively. Human trichomoniasis is the most common non-viral STD in the world and bovine trichomoniasis causes significant economic losses to breeders. Considering the significant impact of the infections caused by these protozoa and the treatment failures, the search for new therapeutic alternatives becomes crucial. In this study the effect of diamines and amino alcohols in the in vitro viability of trichomonads was evaluated. Screening demonstrated the high activity of diamine 4 against these protozoa. Although cytotoxicity against HMVII cell line and slight hemolysis were observed in vitro, the compound showed no toxic effect on the Galleria mellonella in vivo model. Importantly, diamine 4 was active against both trichomonads species at 6h and 24h of incubation, and these effects was reverted by putrescine, a polyamine, suggesting competition for the same metabolic pathway. These findings indicate that the mechanism of action of diamine 4 is through the polyamine metabolism, a pathway distinct from that presented by metronidazole, the drug usually used to treat trichomoniasis and to which resistance is widely reported. These data demonstrate the importance of diamines as potential novel candidates as anti-T. vaginalis and anti-T. foetus agents.

Adenosine reduces reactive oxygen species and interleukin-8 production by Trichomonas vaginalis-stimulated neutrophils

Trichomonas vaginalis is a flagellated protozoan that affects the human urogenital tract causing 276.4 million new infections a year. The parasite elicits a vaginal mucosal infiltration of immune cells, especially neutrophils which are considered to be primarily responsible for cytological change observed at the infection site as well as the major contributor in the inflammatory response against the parasite. Extracellular nucleotides and their nucleosides are signaling compounds involved in several biological processes, including inflammation and immune responses. Once in the extracellular space, the nucleotides and nucleosides can directly activate the purinergic receptors. Herein, we investigated the involvement of purinergic signaling on the production of reactive oxygen species (ROS) and cytokines by T. vaginalis-stimulated neutrophils. Parasites were able to induce an increase in ROS and IL-8 levels while they did not promote IL-6 secretion or neutrophil elastase activity. Adenine and guanine nucleotides or nucleosides were not able to modulate ROS and cytokine production; however, when T. vaginalis-stimulated neutrophils were incubated with adenosine and adenosine deaminase inhibitor, the levels of ROS and IL-8 were significantly reduced. These immunosuppressive effects were probably a response to the higher bioavailability of adenosine found in the supernatant as result of inhibition of enzyme activity. The involvement of P1 receptors was investigated by immunofluorescence and A1 receptor was the most abundant. Our data show that the influence of purinergic signaling, specifically those effects associated with adenosine accumulation, on the modulation of production of proinflammatory mediators by T. vaginalis-stimulated neutrophils contribute to the understanding of immunological aspects of trichomoniasis.

The anti-Trichomonas vaginalis phloroglucinol derivative isoaustrobrasilol B modulates extracellular nucleotide hydrolysis

Trichomonas vaginalis causes trichomoniasis, a neglected sexually transmitted disease. Due to severe health consequences and treatment failure, new therapeutic alternatives are crucial. Phloroglucinols from southern Brazilian Hypericum species demonstrated anti-T. vaginalis and anti-Leishmania amazonensis activities. The modulation of biochemical pathways involved in the control of inflammatory response by ectonucleotidases, NTPDase, and ecto-5'-nucleotidase represents new targets for combating protozoa. This study investigated the activity of phloroglucinol derivatives of Hypericum species from southern Brazil against T. vaginalis as well as its ability on modulating parasite ectonucleotidases and, consequently, immune parameters through ATP and adenosine effects. Phloroglucinol derivatives screening revealed activity for isoaustrobrasilol B (IC₅₀ 38 μm) with no hemolytic activity. Although the most active compound induced cytotoxicity against a mammalian cell lineage, the in vivo model evidenced absence of toxicity. Isoaustrobrasilol B significantly inhibited NTPDase and ecto-5'-nucleotidase activities, and the immune modulation attributed to extracellular nucleotide accumulation was evaluated. The production of ROS and IL-6 by T. vaginalis-stimulated neutrophils was not affected by the treatment. Conversely, IL-8 levels were significantly enhanced. The associative mechanism of trophozoites death and ectonucleotidases modulation by isoaustrobrasilol B may increase the susceptibility of T. vaginalis to host innate immune cell like neutrophils consequently, contributing to parasite clearance.

Differential Protein Expressions in Virus-Infected and Uninfected Trichomonas vaginalis

Protozoan viruses may influence the function and pathogenicity of the protozoa. Trichomonas vaginalis is a parasitic protozoan that could contain a double stranded RNA (dsRNA) virus, T. vaginalis virus (TVV). However, there are few reports on the properties of the virus. To further determine variations in protein expression of T. vaginalis, we detected 2 strains of T. vaginalis; the virus-infected (V⁺) and uninfected (V⁻) isolates to examine differentially expressed proteins upon TVV infection. Using a stable isotope N-terminal labeling strategy (iTRAQ) on soluble fractions to analyze proteomes, we identified 293 proteins, of which 50 were altered in V⁺ compared with V⁻ isolates. The results showed that the expression of 29 proteins was increased, and 21 proteins decreased in V⁺ isolates. These differentially expressed proteins can be classified into 4 categories: ribosomal proteins, metabolic enzymes, heat shock proteins, and putative uncharacterized proteins. Quantitative PCR was used to detect 4 metabolic processes proteins: glycogen phosphorylase, malate dehydrogenase, triosephosphate isomerase, and glucose-6-phosphate isomerase, which were differentially expressed in V⁺ and V⁻ isolates. Our findings suggest that mRNA levels of these genes were consistent with protein expression levels. This study was the first which analyzed protein expression variations upon TVV infection. These observations will provide a basis for future studies concerning the possible roles of these proteins in host-parasite interactions.

Association between high risk human papillomavirus infection and co-infection with Candida spp. and Trichomonas vaginalis in women with cervical premalignant and malignant lesions

BACKGROUND

Human papillomavirus (HPV) is the necessary cause of cervical cancer. Cervico-vaginal infection with pathogens like Chlamydia is a likely cofactor. The interactions between HPV, Trichomonas vaginalis (TV) and Candida spp. are less understood, though inflammation induced by these pathogens has been demonstrated to facilitate oncogenesis.

OBJECTIVE

Our study aimed to evaluate the association between Candida spp. and TV co-infection with HPV in cervical oncogenesis.

STUDY DESIGN

Women with normal cervix who were high-risk HPV-negative (N=104) and HPV-positive (N=105); women with CIN 1 (N=106) and CIN 2/CIN 3 (N=62) were recruited from a community based cervical cancer screening program. Cervical cancer patients (N=106) were recruited from a tertiary care oncology clinic. High-risk HPV was detected by Hybrid Capture II technique; Candida spp. and TV were detected by culturing the high vaginal swabs followed by microscopic examination in all. The disease status was established by histopathology in all the women.

RESULT

HPV-positive women had significantly higher risk of having precursor lesions (of any grade) and cancer compared to HPV-negative women. Candida spp. or TV infection did not alter the risk of low grade or high grade lesions among HPV- positive women. HPV positive women co-infected with TV had higher risk of cervical cancer but not those co-infected with Candida spp.

CONCLUSION

The higher risk of cancer observed in the women co-infected with HPV and TV without any enhanced risk of CIN 3 suggests secondary infection of the malignant growth by TV rather than any causal role. Co-infection with Candida spp. and/or TV infection did not increase the carcinogenic effect of HPV on cervix.

Multiple HPV infections in female sex workers in Western Kenya: implications for prophylactic vaccines within this sub population

Background

Whilst the imputed role of High Risk (HR) HPV infection in the development of cervical lesions and cancer has been established, the high number of HPV genotypes that Female Sex workers (FSW) harbour warrants that the synergistic effects of potential HR (pHR) and HR HPV genotypes be elucidated to assess the potential impact of prophylactic vaccines. This population in Kenya also harbours a number of other vaginal infections and STIs, including bacterial vaginosis (BV), trichomonas vaginalis (TV) and candida spp.

The aims of this cross-sectional analysis in Kenya are to explore the epidemiology of abnormal cytology and the pairing of pHR/HPV genotypes in HIV-negative and HIV-infected FSW.

Methods

A cross-sectional study design of 616 FSW from Western Kenya aged between 18 and 61 years during 2009–2015 using a peer recruitment sampling strategy.

Results

Of the 599 FSW who underwent cytological examination, 87 had abnormal cytology (14.5%; 95% CI: 12.0–17.6%). A combined prevalence of HPV16 and 18 (29.6%; 95% CI: 22.2–37.8%) was observed in abnormal cytology. HPV 53 and 51 were the most observed pairing in FSW with abnormal cytology. Significant adjusted associations were found between abnormal cytology and TV (aOR: 30; 95% CI: 14.1–62.9), multiple HR HPV (aOR: 3.7; 95% CI: 1.9–7.3), HPV 51 (aOR 3.7; 95% CI 1.6–8.6) and HPV 52 (aOR 6.1; 95% CI: 2.8–13.3).

Conclusion

HPV 51 and 52 were independently associated with abnormal cervical cytology in both HIV negative/positive FSW. The strong association between TV and cervical dysplasia and the high percentage of FSW harbouring more than one STI underscore the need for enhanced STI management within the framework of cervical cancer prevention.

Adenosine, but not guanosine, protects vaginal epithelial cells from Trichomonas vaginalis cytotoxicity

Trichomonas vaginalis causes the most common non-viral sexually transmitted disease worldwide. The cytoadherence and cytotoxicity upon the vaginal epithelial cells are crucial for the infection. Extracellular nucleotides are released during cell damage and, along with their nucleosides, can activate purinoceptors. The opposing effects of nucleotides versus nucleosides are regulated by ectonucleotidases. Herein we evaluated the hemolysis and cytolysis induced by T. vaginalis, as well as the extracellular nucleotide hydrolysis along with the effects mediated by nucleotides and nucleosides on cytotoxicity. In addition, the gene expression of purinoceptors in host cells was determined. The hemolysis and cytolysis exerted by all T. vaginalis isolates presented positive Pearson correlation. All T. vaginalis isolates were able to hydrolyze nucleotides, showing higher NTPDase than ecto-5'-nucleotidase activity. The most cytotoxic isolate, TV-LACM6, hydrolyzes ATP, GTP with more efficiency than AMP and GMP. The vaginal epithelial cell line (HMVII) expressed the genes for all subtypes of P1, P2X and P2Y receptors. Finally, when nucleotides and nucleosides were tested, the cytotoxic effect elicited by TV-LACM6 was increased with nucleotides. In contrast, the cytotoxicity was reversed by adenosine in presence of EHNA, but not by guanosine, contributing to the understanding of the purinergic signaling role on T. vaginalis cytotoxicity.

Associations Between Vaginal Infections and Potential High-risk and High-risk Human Papillomavirus Genotypes in Female Sex Workers in Western Kenya

PURPOSE

Infection with and persistence of high-risk human papillomavirus (HR HPV) are the strongest risk factors for cervical cancer. Little is known about the prevalence and role of concurrent sexually transmitted infections (STIs) found in HPV-infected female sex workers (FSW) in Africa. This study purports to test our a priori hypotheses that STIs are associated with genotypes pertaining to the α-group species 9. The objectives were to determine the prevalence of bacterial vaginosis (BV), Trichomonas vaginalis, and Candida spp in FSW, the association between these STIs and the prevalence of any potential HR and HR HPV genotypes in FSWs.

METHODS

A cross-sectional study design of 616 FSW from Western Kenya aged between 18 and 61 years during 2009-2015 using a peer recruitment sampling strategy. Inclusion criteria for the study entailed female sex and >18 years of age and having engaged in transactional sex in exchange for money, goods, services, or drugs in the last 3 months. Women were excluded if they were pregnant, <18 years of age, had a history of cervical dysplasia or cancer, had current abnormal bleeding, or had a hysterectomy.

FINDINGS

Of the FSW, 33.3% had HIV and 57.7% harbored a potential HR and HR HPV genotype. The 2 most prevalent potential HR and HR genotypes were HPV 16 (16.10%) and HPV 59 (12.20%). BV was the most common infection (48.3%), followed by Trichomonas vaginalis (31.4%) and Candida spp (19.9%). A multivariate regression revealed significant associations with both α-group 9 and 6; BV and HPV 58 (adjusted odds ratio [aOR] = 2.3; 95% CI, 1.0-5.2; P = 0.05), Trichomonas vaginalis and HPV 31 and HPV 35 (aOR = 2.0; 95% CI, 1.0-3.8; P = 0.04 and aOR = 1.8; 95% CI, 1.0-3.3, P = 0.05 respectively); and between Candida spp and HPV 53 (aOR = 2.0; 95% CI, 1.1-4.0; P = 0.03) and 16 (aOR = 1.9; 95% CI, 1.1-3.3; P = 0.03).

IMPLICATIONS

Snowball sampling may have inadvertently excluded FSW less likely to benefit from a social network. Significant associations between BV and HPV 58 and between Candida spp and HPV 16 and 53 suggest the need for sexually transmitted disease management within a cervical cancer prevention program. The probable synergistic effects of the vaginal microbiota should be elucidated, especially within this vulnerable population. Given the potential for FSW to transmit STIs, robust epidemiologic sampling methods are urgently required that account for the heterogeneity of the FSW population.

Trichomoniasis - are we giving the deserved attention to the most common non-viral sexually transmitted disease worldwide?

ETIOLOGY

Trichomonas vaginalis is the etiologic agent of trichomoniasis, the most common non-viral sexually transmitted disease (STD) in the world. Transmission: Trichomoniasis is transmitted by sexual intercourse and transmission via fomites is rare. Epidemiology, incidence and prevalence: The WHO estimates an incidence of 276 million new cases each year and prevalence of 187 million of infected individuals. However, the infection is not notifiable. Pathology/Symptomatology: The T. vaginalis infection results in a variety of clinical manifestations - in most cases the patients are asymptomatic, but some may develop signs typically associated to the disease. Importantly, the main issue concerning trichomoniasis is its relationship with serious health consequences such as cancer, adverse pregnancy outcomes, infertility, and HIV acquisition. Molecular mechanisms of infection: To achieve success in parasitism trichomonads develop a complex process against the host cells that includes dependent- and independent-contact mechanisms. This multifactorial pathogenesis includes molecules such as soluble factors, secreted proteinases, adhesins, lipophosphoglycan that culminate in cytoadherence and cytotoxicity against the host cells. Treatment and curability: The treatment with metronidazole or tinidazole is recommended; however, cure failures remain problematic due to noncompliance, reinfection and/or lack of treatment of sexual partners, inaccurate diagnosis, or drug resistance. Therefore, new therapeutic alternatives are urgently needed. Protection: Strategies for protection including sexual behavior, condom usage, and therapy have not contributed to the decrease on disease prevalence, pointing to the need for innovative approaches. Vaccine development has been hampered by the lack of long-lasting humoral immunity associated to the absence of good animal models.

Symbiotic Association with Mycoplasma hominis Can Influence Growth Rate, ATP Production, Cytolysis and Inflammatory Response of Trichomonas vaginalis

The symbiosis between the parasitic protist Trichomonas vaginalis and the opportunistic bacterium Mycoplasma hominis is the only one currently described involving two obligate human mucosal symbionts with pathogenic capabilities that can cause independent diseases in the same anatomical site: the lower urogenital tract. Although several aspects of this intriguing microbial partnership have been investigated, many questions on the influence of this symbiosis on the parasite pathobiology still remain unanswered. Here, we examined with in vitro cultures how M. hominis could influence the pathobiology of T. vaginalis by investigating the influence of M. hominis on parasite replication rate, haemolytic activity and ATP production. By comparing isogenic mycoplasma-free T. vaginalis and parasites stably associated with M. hominis we could demonstrate that the latter show a higher replication rate, increased haemolytic activity and are able to produce larger amounts of ATP. In addition, we demonstrated in a T. vaginalis-macrophage co-culture system that M. hominis could modulate an aspect of the innate immuno-response to T. vaginalis infections by influencing the production of nitric oxide (NO) by human macrophages, with the parasite-bacteria symbiosis outcompeting the human cells for the key substrate arginine. These results support a model in which the symbiosis between T. vaginalis and M. hominis influences host-microbes interactions to the benefit of both microbial partners during infections and to the detriment of their host.

Comparative analysis of syndromic and PCR-based diagnostic assay reveals misdiagnosis/ overtreatment for trichomoniasis based on subjective judgment in symptomatic patients

Background

Trichomoniasis, a sexually transmitted disease (STD), is caused by Trichomonas vaginalis in both men and women. Screening of trichomoniasis is problematic in resource challenged settings as currently available, inexpensive diagnostic methods are of low sensitivity and/or specificity. In India, National AIDS Control organization (NACO) recommended syndromic case management (SCM) for treatment. The objective of the present study was to compare the utility of the NACO-NACP III Algorithms for STI/RTI treatment used by clinicians with PCR based diagnosis.

Methods

Patients visiting Department of Obstetrics & Gynecology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi from January 2011 to June 2014 were enrolled in the study to compare the diagnostic efficiency of PCR-based assays against SCM. Based on SCM, patients (n = 820) were treated with antibiotics using pre-packed STI/RTI kits (sexually transmitted infection/reproductive tract infection; procured by National AIDS Control/State AIDS Control Society (NACO/SACS), Ministry of Health and Family Welfare, Govt of India.) under National AIDS Control Programme (NACP III) for syndromic case management (SCM). Ectocervical dry swab samples were also obtained from these patients and out of that 634 samples were tested by PCR. Total genomic DNA was extracted from these samples and used as template for PCR amplification using pfoB, gyrA and orf1 gene specific primers for diagnosis of T. vaginalis (TV), Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) respectively.

Results

Out of 6000 patients who visited OPD, 820 (14 %) female patients reported vaginal discharge and were recommended antibiotic treatment for one or more pathogens namely, TV, CT, NG and Candida or for co-infection. On the basis of signs & symptoms and NACO guidelines, the following distribution of various infections was observed: TV (46 %), CT (20 %), coinfection with TV and CT (12 %), coinfection with CT and NG (11 %), coinfection with TV, CT and Candida (7 %) and coinfection with TV and NG (2 %). Others were infected with NG alone (1 %), coinfected with TV and Candida (0.4 %) and 0.3 % were coinfected with CT, NG and Candida. Based on PCR method, 110 (17 %) women tested positive for one or more of these three pathogens while 524 (83 %) women were negative for any of these three pathogens but could be positive for other STIs not tested in this study. Since all the patients (634) were given antibiotics, we estimate that the over-treatment was 85 % while 524 (83 %) patients were also misdiagnosed by SCM.

Conclusions

The over-treatment and inaccurate diagnosis of pathogens due to subjective judgment based on syndromic approach in symptomatic women is a large economic wastage and may also contribute towards increased resistance. The misdiagnosed patients will also serve as a reservoir for transmission of pathogens to their sexual partner.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0133-x) contains supplementary material, which is available to authorized users.

Antichagasic and trichomonacidal activity of 1-substituted 2-benzyl-5-nitroindazolin-3-ones and 3-alkoxy-2-benzyl-5-nitro-2H-indazoles

Two series of new 5-nitroindazole derivatives, 1-substituted 2-benzylindazolin-3-ones (6-29, series A) and 3-alkoxy-2-benzyl-2H-indazoles (30-37, series B), containing differently functionalized chains at position 1 and 3, respectively, have been synthesized starting from 2-benzyl-5-nitroindazolin-3-one 5, and evaluated against the protozoan parasites Trypanosoma cruzi and Trichomonas vaginalis, etiological agents of Chagas disease and trichomonosis, respectively. Many indazolinones of series A were efficient against different morphological forms of T. cruzi CL Brener strain (compounds 6, 7, 9, 10 and 19-21: IC50 = 1.58-4.19 μM for epimastigotes; compounds 6, 19-21 and 24: IC50 = 0.22-0.54 μM for amastigotes) being as potent as the reference drug benznidazole. SAR analysis suggests that electron-donating groups at position 1 of indazolinone ring are associated with an improved antichagasic activity. Moreover, compounds of series A displayed low unspecific toxicities against an in vitro model of mammalian cells (fibroblasts), which were reflected in high values of the selectivity indexes (SI). Compound 20 was also very efficient against amastigotes from Tulahuen and Y strains of T. cruzi (IC50 = 0.81 and 0.60 μM, respectively), showing low toxicity towards cardiac cells (LC50 > 100 μM). In what concerns compounds of series B, some of them displayed moderate activity against trophozoites of a metronidazole-sensitive isolate of T. vaginalis (35 and 36: IC50 = 9.82 and 7.25 μM, respectively), with low unspecific toxicity towards Vero cells. Compound 36 was also active against a metronidazole-resistant isolate (IC50 = 9.11 μM) and can thus be considered a good prototype for the development of drugs directed to T. vaginalis resistant to 5-nitroimidazoles.

Association of Genital Infections Other Than Human Papillomavirus with Pre-Invasive and Invasive Cervical Neoplasia

Human papillomavirus (HPV) is a well-established causative agent of malignancy of the female genital tract and a common Sexually Transmitted Infection. The probable co-factors that prevent spontaneous clearance of HPV and progression to neoplasia are genital tract infections from organisms like Chlamydia, Trichomonas vaginalis etc, smoking, nutritional deficiencies and multiparity. Inflammatory conditions can lead to pre-neoplastic manifestations in the cervical epithelium; however their specific role in cervical carcinogenesis is not yet established. Therefore it is imperative to study the likely association between HPV and co-infection with various common pathogens in the genital tract of women having cervical precancer or cancer. A "Pubmed" search was made for articles in Literature on this topic using the words: Cervical neoplasia, HPV, co-infections, Cervical Intraepithelial Neoplasia (CIN), Trichomonas vaginalis, Candida, Chlamydia and the relevant information obtained was used to draft the review.

Iron from haemoglobin and haemin modulates nucleotide hydrolysis in Trichomonas vaginalis

Extracellular ATP may act as a danger signalling molecule, inducing inflammation and immune responses in infection sites. The ectonucleotidases NTPDase and ecto-5’-nucleotidase are enzymes that modulate extracellular nucleotide levels; these enzymes have been previously characterised in Trichomonas vaginalis. Iron plays an important role in the complex trichomonal pathogenesis. Herein, the effects of iron on growth, nucleotide hydrolysis and NTPDase gene expression in T. vaginalis isolates from female and male patients were evaluated. Iron from different sources sustained T. vaginalis growth. Importantly, iron from haemoglobin (HB) and haemin (HM) enhanced NTPDase activity in isolates from female patients and conversely reduced the enzyme activity in isolates from male patients. Iron treatments could not alter the NTPDase transcript levels in T. vaginalis. Furthermore, our results reveal a distinct ATP, ADP and AMP hydrolysis profile between isolates from female and male patients influenced by iron from HB and HM. Our data indicate the participation of NTPDase and ecto-5’-nucleotidase in the establishment of trichomonas infection through ATP degradation and adenosine production influenced by iron.

Five putative nucleoside triphosphate diphosphohydrolase genes are expressed in Trichomonas vaginalis

Trichomonas vaginalis is a protozoan that parasitizes the human urogenital tract causing trichomoniasis, the most common non-viral sexually transmitted disease. The parasite has unique genomic characteristics such as a large genome size and expanded gene families. Ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) is an enzyme responsible for hydrolyzing nucleoside tri- and diphosphates and has already been biochemically characterized in T. vaginalis. Considering the important role of this enzyme in the production of extracellular adenosine for parasite uptake, we evaluated the gene expression of five putative NTPDases in T. vaginalis. We showed that all five putative TvNTPDase genes (TvNTPDase1-5) were expressed by both fresh clinical and long-term grown isolates. The amino acid alignment predicted the presence of the five crucial apyrase conserved regions, transmembrane domains, signal peptides, phosphorylation and catalytic sites. Moreover, a phylogenetic analysis showed that TvNTPDase sequences make up a clade with NTPDases intracellularly located. Biochemical NTPDase activity (ATP and ADP hydrolysis) is responsive to the serum-restrictive conditions and the gene expression of TvNTPDases was mostly increased, mainly TvNTPDase2 and TvNTPDase4, although there was not a clear pattern of expression among them. In summary, the present report demonstrates the gene expression patterns of predicted NTPDases in T. vaginalis.

Trichomonas vaginalis: pathogenicity and potential role in human reproductive failure

PURPOSE

Trichomonas vaginalis, which colonizes the genitourinary tract of men and women, is a sexually transmitted parasite causing symptomatic or asymptomatic trichomoniasis. The host-parasite relationship is very complex, and clinical symptoms cannot likely be attributed to a single pathogenic effect. Among the many factors responsible for interactions between T. vaginalis and host tissues, contact-dependent and contact-independent mechanisms are important in pathogenicity, as is the immune response.

METHODS

This review focuses on the potential virulence properties of T. vaginalis and its role in female and male infertility.

RESULTS

It highlights the association between T. vaginalis infection and serious adverse health consequences experienced by women, including infertility, preterm birth and low-birth-weight infants. Long-term clinical observations and results of in vitro experimental studies indicate that in men, trichomoniasis has been also associated with infertility through inflammatory damage to the genitourinary tract or interference with sperm function.

CONCLUSION

These results contribute significantly to improving our knowledge of the role of parasitic virulence factors in the development of infection and its role in human infertility.

Molecular typing of the actin gene of Trichomonas vaginalis isolates by PCR-RFLP in Iran

Trichomonas vaginalis is a human urogenital pathogen that causes trichomoniasis, the most common nonviral, parasitic sexually transmitted infection in the world. At present, little is known regarding the degree of strain variability of T. vaginalis. A classification method for T. vaginalis strains would be a useful tool in the study of the epidemiology, drug resistance, pathogenesis and transmission of T. vaginalis. Eight different types of actin genes have been identified by PCR-RFLP in T. vaginalis; the purpose of this study is to determine the genotypes of this parasite in Karaj city, Iran. Forty-five clinical T. vaginalis isolates from vaginal secretions and urine sediment were collected from Karaj city from 2012 through 2014. DNA was extracted and the actin gene was amplified by nested-PCR; all samples were positive. To determine the genetic differences, sequencing on seven samples was conducted. Then, all PCR products were digested with HindII, MseI, and RsaI restriction enzymes. Of 45 isolates, 23 samples (51.1%) were of actin genotype G, 11 samples (24.4%) of genotype E, six samples (13.3%) of genotype H, three samples (6.6%) of genotype I, and two samples (4.4%) were mixed genotypes of G and E. Genetic diversity of T. vaginalis isolates is notable. The actin genotype G may be the dominant genotype in Karaj city, Iran.

Modulatory effect of iron chelators on adenosine deaminase activity and gene expression in Trichomonas vaginalis

Trichomonas vaginalis is a flagellate protozoan that parasitises the urogenital human tract and causes trichomoniasis. During the infection, the acquisition of nutrients, such as iron and purine and pyrimidine nucleosides, is essential for the survival of the parasite. The enzymes for purinergic signalling, including adenosine deaminase (ADA), which degrades adenosine to inosine, have been characterised in T. vaginalis. In the evaluation of the ADA profile in different T. vaginalis isolates treated with different iron sources or with limited iron availability, a decrease in activity and an increase in ADA gene expression after iron limitation by 2,2-bipyridyl and ferrozine chelators were observed. This supported the hypothesis that iron can modulate the activity of the enzymes involved in purinergic signalling. Under bovine serum limitation conditions, no significant differences were observed. The results obtained in this study allow for the assessment of important aspects of ADA and contribute to a better understanding of the purinergic system in T. vaginalis and the role of iron in establishing infection and parasite survival.

Optimal Reference Genes for Gene Expression Normalization in Trichomonas vaginalis

Trichomonas vaginalis is the etiologic agent of trichomonosis, the most common non-viral sexually transmitted disease worldwide. This infection is associated with several health consequences, including cervical and prostate cancers and HIV acquisition. Gene expression analysis has been facilitated because of available genome sequences and large-scale transcriptomes in T. vaginalis, particularly using quantitative real-time polymerase chain reaction (qRT-PCR), one of the most used methods for molecular studies. Reference genes for normalization are crucial to ensure the accuracy of this method. However, to the best of our knowledge, a systematic validation of reference genes has not been performed for T. vaginalis. In this study, the transcripts of nine candidate reference genes were quantified using qRT-PCR under different cultivation conditions, and the stability of these genes was compared using the geNorm and NormFinder algorithms. The most stable reference genes were α-tubulin, actin and DNATopII, and, conversely, the widely used T. vaginalis reference genes GAPDH and β-tubulin were less stable. The PFOR gene was used to validate the reliability of the use of these candidate reference genes. As expected, the PFOR gene was upregulated when the trophozoites were cultivated with ferrous ammonium sulfate when the DNATopII, α-tubulin and actin genes were used as normalizing gene. By contrast, the PFOR gene was downregulated when the GAPDH gene was used as an internal control, leading to misinterpretation of the data. These results provide an important starting point for reference gene selection and gene expression analysis with qRT-PCR studies of T. vaginalis.