Trichomoniasis

Epidemiology of Trichomonas vaginalis infection in the Middle East and North Africa: systematic review, meta-analyses, and meta-regressions

BACKGROUND

Trichomoniasis, caused by the parasite Trichomonas vaginalis (TV), remains an underappreciated sexually transmitted infection (STI), primarily due to inadequate understanding of its epidemiology and public health implications. This study aimed to characterize TV epidemiology in the Middle East and North Africa (MENA).

METHODS

Systematic review and analysis of evidence sourced from international, regional, and national databases were conducted. Findings were reported following PRISMA guidelines. Random-effects meta-analyses and meta-regressions were performed to determine pooled mean prevalence, investigate associations with prevalence, and identify sources of between-study heterogeneity.

FINDINGS

The review identified 263 relevant publications, encompassing 462 TV prevalence measures. The pooled mean TV prevalence was estimated as follows: 4.7% (95% CI: 3.9-5.6%) in the general population of women, 17.2% (95% CI: 5.4-33.6%) among intermediate-risk populations, 10.3% (95% CI: 6.2-15.3%) among female sex workers, 13.9% (95% CI: 12.3-15.6%) among symptomatic women, 7.4% (95% CI: 1.9-15.5%) among infertility clinic attendees, 2.3% (95% CI: 0.1-6.3%) among women with miscarriages or ectopic pregnancies, and 1.6% (95% CI: 0.8-2.7%) among STI clinic attendees. Limited data were found for men. Multivariable meta-regressions explained >40% of the prevalence variation, unveiling a hierarchical prevalence pattern by population type, an inverse correlation with national income, and a prevalence decline at a rate of 1% per calendar year.

INTERPRETATION

Despite conservative sexual norms, MENA has a substantial TV prevalence, comparable to the global TV prevalence. The unexpectedly high prevalence of this curable infection may, in part, be attributed to limited access to and underutilization of STI screening and treatment services.

FUNDING

This work was supported by the Qatar Research, Development, and Innovation Council [ARG01-0522-230273] and by the Biomedical Research Program at Weill Cornell Medicine-Qatar.

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.

Case series on Trichomonas vaginalis infections: impact of proper sample collection and diagnostic stewardship

This paper elucidates the transformative impact of a strategic shift in diagnostic practices in the detection of Trichomonas vaginalis. It explores five cases where the implementation of a specific diagnostic protocol led to effective identification of the infection. In-depth discussions and a comprehensive literature review underline the necessity for precise diagnosis and the paramount importance of diagnostic stewardship in managing sexually transmitted infections.

Drug Repurposing in the Chemotherapy of Infectious Diseases

Repurposing is a universal mechanism for innovation, from the evolution of feathers to the invention of Velcro tape. Repurposing is particularly attractive for drug development, given that it costs more than a billion dollars and takes longer than ten years to make a new drug from scratch. The COVID-19 pandemic has triggered a large number of drug repurposing activities. At the same time, it has highlighted potential pitfalls, in particular when concessions are made to the target product profile. Here, we discuss the pros and cons of drug repurposing for infectious diseases and analyze different ways of repurposing. We distinguish between opportunistic and rational approaches, i.e., just saving time and money by screening compounds that are already approved versus repurposing based on a particular target that is common to different pathogens. The latter can be further distinguished into divergent and convergent: points of attack that are divergent share common ancestry (e.g., prokaryotic targets in the apicoplast of malaria parasites), whereas those that are convergent arise from a shared lifestyle (e.g., the susceptibility of bacteria, parasites, and tumor cells to antifolates due to their high rate of DNA synthesis). We illustrate how such different scenarios can be capitalized on by using examples of drugs that have been repurposed to, from, or within the field of anti-infective chemotherapy.

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.

A novel detection method based on MIRA-CRISPR/Cas13a-LFD targeting the repeated DNA sequence of Trichomonas vaginalis

BACKGROUND

Trichomonas vaginalis is a protozoan parasite, widely recognized as the most prevalent non-viral sexually transmitted infection (STI) globally. This infection is linked to various complications, including pelvic inflammatory disease, adverse pregnancy outcomes, and an increased risk of acquiring HIV. Current molecular detection methods for T. vaginalis are often costly and technically challenging.

METHODS

We developed a novel detection method for T. vaginalis using a multi-enzyme isothermal rapid amplification-clustered regularly interspaced short palindromic repeats (MIRA-CRISPR)/Cas13a-lateral flow device (LFD). This assay targets the repeated DNA sequence (GenBank: L23861.1) of T. vaginalis and is performed at a constant temperature of 37 °C for approximately 1 hour.

RESULTS

The detection limit of genomic DNA (gDNA) using our protocol was 1 × 10-4 ng/μl. Specificity was confirmed by the absence of cross-reaction with gDNA from various other microorganisms such as Staphylococcus aureus, Lactobacillus taiwanensis, Escherichia coli, Monilia albicans, Giardia lamblia, or Toxoplasma gondii. Among 30 clinical samples tested, the positive rates of T. vaginalis detection were 33.33% (10/30) by wet mount microscopy, 40% (12/30) by nested polymerase chain reaction (PCR), 40% (12/30) by MIRA-CRISPR/Cas13a-LFD, and 40% (12/30) by the culture method. Compared with the culture method, the gold standard for diagnosing trichomoniasis, wet mount microscopy showed a sensitivity of 83.3% and moderate diagnostic agreement (kappa value = 0.87). Both nested PCR and MIRA-CRISPR/Cas13a-LFD exhibited 100% sensitivity and excellent diagnostic agreement (kappa value = 1).

CONCLUSIONS

The MIRA-CRISPR/Cas13a-LFD method is a convenient, rapid, stable, and accurate diagnostic tool for detecting T. vaginalis. This method has the potential to enhance the diagnosis and management of vaginitis, offering a significant improvement over existing diagnostic techniques.

Trichomonas vaginalis and Associated Factors among Pregnant Women Attending Antenatal Care at Bule Hora University Teaching Hospital, Oromia Region, Southern Ethiopia

Trichomoniasis is caused by a flagellated protozoan parasite called Trichomonas vaginalis. It is one of the most common, curable nonsexually transmitted infections globally. In Ethiopia, complications associated with genital infection in pregnant women are a common problem. Despite the burden of the disease, epidemiological data related to this disease is currently rare in Africa, particularly in Ethiopia. Objective. This research is aimed at assessing the prevalence of Trichomonas vaginalis and associated factors among pregnant women attending antenatal care at Bule Hora University Teaching Hospital. Methods. An institutional-based cross-sectional study was conducted among 196 pregnant women attending ANC at Bule Hora University Teaching Hospital. Structured questionnaires were used to collect sociodemographic and associated factor data. The consecutive sampling technique was used to include study participants. The two vaginal swabs were collected by brushing the vagina with a sterile cotton swab and tested by using direct wet mount and the Giemsa staining. The data were analyzed using SPSS version 26 for logistic regression analysis. A p value < 0.05 with 95% CI was used to declare it statistically significant. Result. An overall prevalence of T. vaginalis among pregnant women was 7.7% (95% with confidence interval (CI), 0.043-0.123). The highest prevalence was observed among the 35-39-year-old age group with 18.2% and among widowed women with 25%. This study revealed that the number of sexual partners (AOR: 3.215, 95% CI: 1.062-9.731) was a significant associated factor of T. vaginalis.Conclusion. The prevalence of T. vaginalis was considerably high among pregnant women in this study. This finding emphasizes the need for routine screening and treatment of pregnant women in the first antenatal care and enhances the need for regular health education for pregnant women at antenatal clinics to make them aware of their health, and avoidance of the risk of trichomoniasis is advised.

Comparison of Three Methods for Diagnosing Trichomoniasis in Female Patients with Sexual Activity Attended at a Hospital in Peru

Background

Trichomoniasis is a sexually transmitted infection that mainly affects women. The diagnosis is made by different methods that identify the presence of Trichomonas vaginalis; therefore, sensitivity, specificity, and performance are essential to guarantee an adequate diagnosis. Our study is aimed at comparing three methods for diagnosing trichomoniasis in patients treated at a hospital in Peru during the year 2018.

Methods

We designed a cross-sectional study and enrolled women whose vaginal secretion samples were evaluated by direct examination, Papanicolaou staining, and culture in the Diamond medium.

Results

We evaluated 134 women with a mean age of 36.6 ± 12.1 years and a beginning of sexual activity of 18.5 ± 3.0 years. We found leukocyte infiltration, fetid odor, and strawberry cervix in 66.4%, 35.1%, and 18.7%. The prevalence of trichomoniasis by the culture method, direct examination, and Papanicolaou was 32.1, 21.6, and 11.2%. The direct examination's sensitivity, specificity, and diagnostic performance (AUC) were 65.1%, 98.9%, and 82.0%, while for the Pap smear, they were 32.6%, 98.9%, and 65.7%%.

Conclusion

The culture of T. vaginalis is the gold standard for diagnosing trichomoniasis; however, direct examination is a fast, specific alternative with good diagnostic performance. The Pap test has low sensitivity and should not be used in settings where the prevalence and risk factors for trichomoniasis are high.

Trichomonas vaginalis adherence phenotypes and extracellular vesicles impact parasite survival in a novel in vivo model of pathogenesis

Trichomonas vaginalis is a human infective parasite responsible for trichomoniasis-the most common, non-viral, sexually transmitted infection worldwide. T. vaginalis resides exclusively in the urogenital tract of both men and women. In women, T. vaginalis has been found colonizing the cervix and vaginal tract while in men it has been identified in the upper and lower urogenital tract and in secreted fluids such as semen, urethral discharge, urine, and prostatic fluid. Despite the over 270 million cases of trichomoniasis annually worldwide, T. vaginalis continues to be a highly neglected organism and thus poorly studied. Here we have developed a male mouse model for studying T. vaginalis pathogenesis in vivo by delivering parasites into the murine urogenital tract (MUT) via transurethral catheterization. Parasite burden was assessed ex-vivo using a nanoluciferase-based gene expression assay which allowed quantification of parasites pre- and post-inoculation. Using this model and read-out approach, we show that T. vaginalis can be found within MUT tissue up to 72 hrs post-inoculation. Furthermore, we also demonstrate that parasites that exhibit increased parasite adherence in vitro also have higher parasite burden in mice in vivo. These data provide evidence that parasite adherence to host cells aids in parasite persistence in vivo and molecular determinants found to correlate with host cell adherence in vitro are applicable to infection in vivo. Finally, we show that co-inoculation of T. vaginalis extracellular vesicles (TvEVs) and parasites results in higher parasite burden in vivo. These findings confirm our previous in vitro-based predictions that TvEVs assist the parasite in colonizing the host. The establishment of this pathogenesis model for T. vaginalis sets the stage for identifying and examining parasite factors that contribute to and influence infection outcomes.

Genetic Variability of the Internal Transcribed Spacer and Pyruvate:Ferredoxin Oxidoreductase Partial Gene of Trichomonas vaginalis from Female Patients

In the present study, we evaluated the genetic variability of the internal transcribed spacer (ITS) region and the pyruvate:ferredoxin oxidoreductase (pfor) A gene of Trichomonas vaginalis from female patients and its possible implications in the host-parasite relationship. Phylogenetic and genetics of populations analyses were performed by analyzing sequences of the ITS region and partial pfor A gene of clinical samples with T. vaginalis, as previously documented. Alignments of protein sequences and prediction of three-dimensional structure were also performed. Although no correlation between the main clinical characteristics of the samples and the results of phylogeny was found, a median-joining analysis of ITS haplotypes showed two main clusters. Also, pfor A, due to its phylogenetic divergence, could be used as a marker to confirm the genus and species of trichomonads. Alignment of protein sequences and prediction of three-dimensional structure showed that PFOR A had a highly conserved structure with two synonymous mutations in the PFOR domain, substituting a V for a G or a S for a P. Our results suggest that the role of genetic variability of PFOR and ITS may not be significant in the symptomatology of this pathogen; however, their utility as genus and species markers in trichomonads is promising.

Carrageenan/Chitin Nanowhiskers Cryogels for Vaginal Delivery of Metronidazole

The development of polymeric carriers based on partially deacetylated chitin nanowhiskers (CNWs) and anionic sulfated polysaccharides is an attractive strategy for improved vaginal delivery with modified drug release profiles. This study focuses on the development of metronidazole (MET)-containing cryogels based on carrageenan (CRG) and CNWs. The desired cryogels were obtained by electrostatic interactions between the amino groups of CNWs and the sulfate groups of CRG and by the formation of additional hydrogen bonds, as well as by entanglement of carrageenan macrochains. It was shown that the introduction of 5% CNWs significantly increased the strength of the initial hydrogel and ensured the formation of a homogeneous cryogel structure, resulting in sustained MET release within 24 h. At the same time, when the CNW content was increased to 10%, the system collapsed with the formation of discrete cryogels, demonstrating MET release within 12 h. The mechanism of prolonged drug release was mediated by polymer swelling and chain relaxation in the polymer matrix and correlated well with the Korsmeyer-Peppas and Peppas-Sahlin models. In vitro tests showed that the developed cryogels had a prolonged (24 h) antiprotozoal effect against Trichomonas, including MET-resistant strains. Thus, the new cryogels with MET may be promising dosage forms for the treatment of vaginal infections.

Identification of volatile biomarkers of Trichomonas vaginalis infection in vaginal discharge and urine

Trichomoniasis, a disease caused by Trichomonas vaginalis, is the most common non-viral sexually transmitted infection worldwide. The importance of its diagnosis lies in its ease of transmission and the absence of symptoms in most cases, as occurs in men, which have a significant role as asymptomatic carriers. The most widely used diagnostic methods are the fresh examination of vaginal or urethral secretions and molecular techniques. However, as they have some disadvantages and, sometimes, low sensitivity, new trichomoniasis diagnostic methods are necessary. Volatile organic compounds in clinical samples are effective in the diagnosis of different diseases. This work aimed to study, for the first time, those present in vaginal discharge and urine of patients with Trichomonas vaginalis infection to look for volatile biomarkers. The results showed that volatile compounds such as 2-methyl-1-propanol and cyclohexanone could serve as biomarkers in vaginal discharge samples, as well as 2-octen-1-ol and 3-nonanone in urine. Moreover, 3-hydroxy-2,4,4-trimethylpentyl 2-methylpropanoate found in vaginal discharge, highly correlated to positive patients, is also highly related to urines of patients with trichomoniasis. The biomarkers described in this study might be a promising diagnostic tool. KEY POINTS: • The incidence of Trichomonas vaginalis infection is increasing • Trichomonas vaginalis VOC study in vaginal discharge and urine was performed • The identification of volatile biomarkers could allow a new diagnostic method.

Novel therapeutic opportunities for Toxoplasma gondii, Trichomonas vaginalis and Giardia intestinalis infections

INTRODUCTION

Toxoplasma gondii, Trichomonas vaginalis and Giardia intestinalis are the causative agents of Toxoplasmosis, Trichomoniasis and Giardiasis, three important infections threatening human health and affecting millions of people worldwide. Although drugs and treatment are available to fight these protozoan parasites, side-effects and increasing drug resistance, require continuous efforts for the development of novel effective drugs.

AREAS COVERED

The patents search was carried out in September/October 2022 with four official scientific databases (Espacenet, Scifinder, Reaxys, Google Patents). Treatments for Toxoplasmosis, Trichomoniasis and Giardiasis (2015-2022) have been grouped according to their chemotypes. In particular, novel chemical entities have been reported and investigated for their structure-activity relationship, when accessible. On the other hand, drug repurposing, extensively exploited to obtain novel anti-protozoal treatment, has been in-depth described. Finally, natural metabolites and extracts have also been reported.

EXPERT OPINION

T. gondii, T. vaginalis and G. intestinalis are protozoan infections usually controlled by immune system in immunocompetent patients; however, they could represent a threatening health for immunocompromised people. The needs of novel effective drugs, endowed with new mechanisms of actions arises from the increasing drug resistance affecting antibiotic as well as antiprotozoal therapies. In this review different therapeutic approaches to treat protozoan infections have been reported.

Development of subunit selective substrates for Trichomonas vaginalis proteasome

The protozoan parasite, Trichomonas vaginalis (Tv) causes trichomoniasis, the most common, non-viral, sexually transmitted infection in the world. Only two closely related drugs are approved for its treatment. The accelerating emergence of resistance to these drugs and lack of alternative treatment options poses an increasing threat to public health. There is an urgent need for novel effective anti-parasitic compounds. The proteasome is a critical enzyme for T. vaginalis survival and was validated as a drug target to treat trichomoniasis. However, to develop potent inhibitors of the T. vaginalis proteasome, it is essential that we understand which subunits should be targeted. Previously, we identified two fluorogenic substrates that were cleaved by T. vaginalis proteasome, however after isolating the enzyme complex and performing an in-depth substrate specificity study, we have now designed three fluorogenic reporter substrates that are each specific for one catalytic subunit. We screened a library of peptide epoxyketone inhibitors against the live parasite and evaluated which subunits are targeted by the top hits. Together we show that targeting of the β5 subunit of T. vaginalis is sufficient to kill the parasite, however, targeting of β5 plus either β1 or β2 results in improved potency.

Multiple Regulations of Parasitic Protozoan Viruses: A Double-Edged Sword for Protozoa

Parasite infections affect human and animal health significantly and contribute to a major burden on the global economy. Parasitic protozoan viruses (PPVs) affect the protozoan parasites' morphology, phenotypes, pathogenicity, and growth rates. This discovery provides an opportunity to develop a novel preventive and therapeutic strategy for parasitic protozoan diseases (PPDs). Currently, there is greater awareness regarding PPVs; however, knowledge of viruses and their associations with host diseases remains limited. Parasite-host interactions become more complex owing to PPVs; however, few studies have investigated underlying viral regulatory mechanisms in parasites. In this study, we reviewed relevant studies to identify studies that investigated PPV development and life cycles, the triangular association between viruses, parasites, and hosts, and the effects of viruses on protozoan pathogenicity. This study highlights that viruses can alter parasite biology, and viral infection of parasites may exacerbate the adverse effects of virus-containing parasites on hosts or reduce parasite virulence. PPVs should be considered in the prevention of parasitic epidemics and outbreaks, although their effects on the host and the complexity of the triangular association between PPVs, protozoans, and hosts remain unclear. IMPORTANCE PPVs-based regulation of parasitic protozoa can provide a theoretical basis and direction for PPD prevention and control, although PPVs and PPV regulatory mechanisms remain unclear. In this review, we investigated the differences between PPVs and the unique properties of each virus regarding virus discovery, structures, and life cycles, focused on the Trichomonas vaginalis virus, Giardia lamblia virus, Leishmania RNA virus, and the Cryptosporidium parvum virus 1. The triangular association between PPVs, parasitic protozoa, and hosts reveals the "double-edged sword" property of PPVs, which maintains a balance between parasitic protozoa and hosts in both positive and negative respects. These studies discuss the complexity of parasitic protozoa and their co-existence with hosts and suggest novel pathways for using PPVs as tools to gain a deeper understanding of protozoal infection and treatment.

A review of the bioactive components and pharmacological properties of Lavandula species

Lavandula species is a flowering plant that is common in Europe and across the Mediterranean. Lavender has many health benefits for humans. In addition to its use in herbal medicine, it is widely used in the fields of cosmetics, perfumes, foods, and aromatherapy. Google Scholar, PubMed, Scopus, and Web of Science were used to search for relevant material on the phytochemical ingredients, the pharmacologic effects of the ingredients, and the mechanism of action of the Lavandula species identified. These materials were reviewed in order to have access to important updates about the Lavandula species. Lavender as referred to in English contains essential oils, anthocyanins, phytosterols, sugars, minerals, coumaric acid, glycolic acid, valeric acid, ursolic acid, herniarins, coumarins, and tannins. It has been used to treat colic and chest ailments, worrisome headaches, and biliousness, and in cleaning wounds. It has antifungal, antibacterial, neurologic, antimicrobial, anti-parasitic, anti-diabetic, and analgesic effects among others. Lavandula species has prospects for various biological applications, especially with its dermatological application. Advances in drug development would enable characterization of various bioactive constituents; thus, its development and application can have a more positive impact on humanity. Here, we highlighted updated information on the history, distribution, traditional uses, phytochemical components, pharmacology, and various biological activities of Lavandula species.

Trichomonas tenax: A Neglected Protozoan Infection in the Oral Cavities of Humans and Dogs-A Scoping Review

Trichomonas tenax is a flagellated protozoan parasite found in the oral cavities of humans and animals and has been associated with periodontal disease, the most prevalent inflammatory disease affecting them all. Studies have shown that T. tenax can cause damage to mammalian cells and secretes virulent proteins, such as cysteine. It is presently considered zoonotic. Despite the few studies that have been done, the pathogenicity of this oral protozoan is still not fully understood. A database search was performed in July 2022 using PubMed and Google Scholar to retrieve data eligible for this study. PRISMA-ScR guidelines were followed to conduct this scoping review. A total of 321 articles were found with 87 included in this review after applying the exclusion criteria. Due to its increasing prevalence worldwide in both humans and dogs, detecting and elucidating the pathogenicity of this parasite is paramount for effective global control and prevention of periodontal disease. However, there is a paucity in the literature on this neglected zoonotic trichomonad, which is in large contrast to the closely related human pathogen T. vaginalis. Here, we comprehensively review the history, morphology and reproduction, host, prevalence, diagnosis, pathogenicity, control, and prevention of T. tenax. Hopefully, this article will call attention to both medical and veterinary professionals as well as epidemiologists on this most neglected and zoonotic protozoan. More epidemiological and clinical studies need to be conducted on T. tenax to gain a better understanding of its pathogenicity, to increase the chances of developing effective drugs to aid in the control of this oral parasite, and reduce the spread of periodontal disease worldwide.

The prevalence and risk factors of Trichomonas vaginalis in Wuhan and the Tibetan area, China: a two-center study

Trichomonas vaginalis (T. vaginalis) infection is one of the most common sexually transmitted infections worldwide and is associated with several complications. However, the paucity of research regarding the prevalence of T. vaginalis infection in the Tibetan area limits control efforts. We aimed to evaluate the prevalence of T. vaginalis infection in the Tibetan area by a comparison with the prevalence of T. vaginalis in Wuhan city and to unveil the potential risk factors in the Tibetan area. This descriptive, cross-sectional study was conducted among adult women attending gynecology outpatient clinics in two public hospitals (one in Shannan city of Tibet and one in Wuhan city) in China in 2020. Data were retrieved from the medical record system and laboratory information management system, including T. vaginalis infection, bacterial vaginosis, and vulvovaginal candidiasis by wet mount microscopy or nucleic acid hybridization of vaginal secretions from patients. The associations of variables associated with T. vaginalis prevalence were quantified by odds ratios with 95% confidence intervals. The overall prevalence rates of T. vaginalis infection in the Tibetan area and Wuhan city were 20.94% and 2.84%, respectively. The statistically significant factors for the higher prevalence of T. vaginalis infection in the Tibetan area included tertiary educational status (AOR: 0.36 [95% CI: 0.16-0.81]), yearly family income > ¥100,000 (AOR: 0.48 [95% CI: 0.26-0.91]), clinical symptoms (AOR: 4.58[95% CI: 2.32-9.04]), and III-IV grade vaginal cleanliness (AOR: 29.71 [95% CI: 3.95-223.56]) in the multivariate logistic analysis. Interventions targeting improved living standards as well as women's educational level and promoting reproductive hygiene habits are recommended to contribute to the reduction in T. vaginalis infection in the Tibetan area.

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.

Activity of Apo-Lactoferrin on Pathogenic Protozoa

Parasites and other eventually pathogenic organisms require the ability to adapt to different environmental conditions inside the host to assure survival. Some host proteins have evolved as defense constituents, such as lactoferrin (Lf), which is part of the innate immune system. Lf in its iron-free form (apo-Lf) and its peptides obtained by cleavage with pepsin are microbicides. Parasites confront Lf in mucosae and blood. In this work, the activity of Lf against pathogenic and opportunistic parasites such as Cryptosporidium spp., Eimeria spp., Entamoeba histolytica, Giardia duodenalis, Leishmania spp., Trypanosoma spp., Plasmodium spp., Babesia spp., Toxoplasma gondii, Trichomonas spp., and the free-living but opportunistic pathogens Naegleria fowleri and Acanthamoeba castellani were reviewed. The major effects of Lf could be the inhibition produced by sequestering the iron needed for their survival and the production of oxygen-free radicals to more complicated mechanisms, such as the activation of macrophages to phagocytes with the posterior death of those parasites. Due to the great interest in Lf in the fight against pathogens, it is necessary to understand the exact mechanisms used by this protein to affect their virulence factors and to kill them.

Local cytokine/chemokine profiles in BALB/c and C57BL/6 mice in response to T. vaginalis infection

Trichomonas vaginalis is the causative agent of Trichomoniasis (a sexually transmitted infection). Recent reports have shown that stimulation of cellular immunity can reduce trichomoniasis infection. Animal studies are essential to understanding the pathogenesis of infection and developing new potential drugs and vaccines to treat the infection. Therefore, we have tried to understand the pathogenesis of T. vaginalis infection by investigating the differences in the expression of chemokine/cytokine levels in vaginal and cervical tissues of BALB/c and C57BL/6 mice. Different pathological symptoms, like desquamation, neutrophil infiltration, and hemorrhage, were recorded in BALB/c and C57BL/6 in response to T. vaginalis infection. Vaginal and cervical tissues of BALB/c showed these symptoms on 2nd dpi, which became severe on 7th dpi and turned to mild or normal till 14th dpi compared to C57BL/6 strain. Immunohistochemistry in the vagina and cervical tissues of BALB/c and C57BL/6 mice was done to assess cytokines at different time intervals post-infection. Significant expression of Interleukin-1β (IL-1β) (a pro-inflammatory cytokine) was found in BALB/c compared to the C57BL/6 mice, on 7th dpi and 2nd dpi in vaginal and cervical tissues, respectively. Higher expression of MIP-2 (neutrophil chemoattractant) was observed in the vaginal tissues of BALB/c mice on 7th dpi compared to the C57BL/6 group. In addition, higher expression of TGF-β (immune-suppressor) was observed on 7th dpi in the vaginal tissue of BALB/c mice. The present study demonstrates that more pathological signs of T. vaginalis infection developed in BALB/c mice than C57BL/6 mice. Also, significant levels of IL-1β and MIP-2 were measured in BALB/c mice in response to T. vaginalis compared to C57BL/6.

Molecular characterization of Trichomonas infections in women of Ilam City, southwestern Iran

Trichomoniasis is a sexually transmitted infection (STI) caused by the flagellated protozoan Trichomonas vaginalis. Little information is available on the epidemiology and genetic diversity of T. vaginalis in Ilam City, southwestern Iran. A descriptive cross-sectional investigation was carried out between July 2017 and December 2018 on the suspected women patients referred to eight gynecology clinics of Ilam City for probable Trichomonas infection. They were undergone a set of clinical, parasitological, and molecular examinations. During clinical consultation, posterior vaginal fornix secretions and urine samples were gathered from the participants. For the reasons such as physical conditions and cultural and religious constraints, most of participating women, especially young girls due to their virginity, preferred to give urine samples instead of vaginal discharge. The presence of Trichomonas was diagnosed by microscopic examination and molecular detection using conventional PCR targeting ITS1-rDNA. A total of 1765 suspected individuals were examined clinically via vaginal secretions (495 specimens) and urine samples (1270 specimens). Of them, 21 (1.18%) cases, including 13 vaginal secretions and 8 urine samples, were positive for Trichomonas infection by microscopy. Slightly more than half of the patients (11/21, 52.4%) complained of vulvar itching, burning, and frequent urination. Cervical lesions, patchy erythema, and vaginal discharge were recorded in 28.6%, 23.8%, and 19% of the patients respectively. All patients with positive microscopic identification were confirmed by amplification of 450-bp fragment of ITS1-rDNA. Phylogenetic analysis revealed a high rate of genetic homogeneity in which all our isolates together with homologous sequences from China, Philippines, Austria, and USA were clustered within the same clade. A statistically significant relationship was recorded between the patients positive for trichomoniasis and the presence of chronic disease (e.g., diabetes, immune system deficiency).

Trichomoniasis, a new look at a common but neglected STI in African descendance population in the United States and the Black Diaspora. A review of its incidence, research prioritization, and the resulting health disparities

Structural racism plays a significant role in limited access to higher education, financial resources, employment opportunities, and high-quality healthcare for African Americans. The lack of healthcare equity and infrastructure has directly contributed to overall poor healthcare outcomes for the Black community. Studies have shown that adverse health outcomes such as sexually transmitted diseases (STDs) are more prevalent in African Americans, regardless of their socioeconomic factors and lifestyles. For example, trichomoniasis, transmitted sexually by its etiological agent, Trichomonas vaginalis (T. vaginalis), predisposes those infected to co-infections with other STDs, such as human immunodeficiency virus (HIV), herpes, and other related infections. Our review showcases the impact of trichomoniasis on the health of the Black community with an emphasis on African American women. A critical examination of the socio-demographic history of Black people in the United States (US) is vital to illustrate the origin of past and current racial health disparities. Further, we expand the complex and nuanced conversation on the intersectionality of racism, health equity, and innovative epidemiological and biomedical research strategies needed to eradicate this global public health threat.

Native Iranian Medicinal Plants with Anti-Vaginal Infection Properties: A Systematic Review

BACKGROUND

The use of herbs has recently been considered an effective method in the treatment of infections. The purpose of this study was to introduce Iranian medicinal plants with an effect on vaginal infections.

METHODS

In our systematic review study, keywords including 'medicinal plants', 'Iranian medicinal plants', 'vaginal infection', 'essential oils', and 'extracts' were searched in PubMed, Web of Science Direct, Scopus, Scientific Information Database, and Google Scholar. This study focused on the articles published from 2000 to 2019.

RESULTS AND DISCUSSION

According to our investigation, Stachys lavandulifolia, Thymus vulgaris L., Origanum vulgare L., Allium jesdianum, Cichorium intybus, Trigonella foenum-graecum, Azadirachta Indica, Stachys lavandulifolia, Coriandrum sativum L., Rosmarinus officinalis, Ferula gummosa L., Origanum syriacum, Eucalyptus globulus, Myrtus communis, Zingiber officinale, Punica granatum, Vitex agnus-castus, Mentha suaveolens, Quercus Brantii Lindl, Zataria multiflora, Berberis vulgaris, Thymus vulgaris L., Echinophora platyloba, Stachys lavandulifolia, Viola odorata, Menthe piperita, Eucalyptus camaldulensis, Ziziphus mauritiana, Quercus infectoria, Hypericum perforatum, Glycyrrhiza glabra L., Calendula officinalis, Origanum vulgare, Ziziphus nummularia, Satureja Bachtiarica, Foeniculum vulgare, Nigella sativa, Anethum graveolens, Salvia officinalis, and Calendula officinalis are used to treat vaginal infections.

CONCLUSION

Therefore, native plants of Iran have been reported to have antimicrobial properties for the treatment of vaginal infections and can be used as a suitable and effective alternative to antibiotics in future research.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Comparison of diagnostic methods and analysis of socio-demographic factors associated with Trichomonas vaginalis infection in Sri Lanka

BACKGROUND

Trichomonas vaginalis infection is underreported due to nonspecific clinical presentation and the nonavailability of sensitive laboratory diagnostic tests at the clinical setup. Hence, this study was designed to compare the sensitivity and specificity of microscopy and culture methods with polymerase chain reaction (PCR). The socio-demographic factors associated with the infection were explored.

METHODS

The study was carried out at the National Sexually Transmitted Diseases and Acquired Immuno Deficiency Syndrome Control Programme in Colombo and Sexually Transmitted Diseases and Acquired Immuno Deficiency Syndrome Control Programme in Kandy. Samples were collected from a total of 385 patients including, 272 females (70.7%) and 113 males (29.3%), and tested using microscopy (wet mount and Giemsa staining), culture, and PCR. Genus-specific primer set (TFR1/TFR2) that amplifies 5.8S rRNA and species-specific primer sets (TV16Sf-2/TV16Sr-2 and TVK3/7) that amplifies 18S rRNA and repetitive DNA, respectively, were used. Patient's socio-demographic and sexual behaviour data were obtained using a standard interviewer-administered questionnaire. Data were analyzed with R statistical software Version 3.6.3.

RESULTS

The overall prevalence of trichomoniasis was 4.4% (17/385). Of these, six (1.6%) were positive for microscopic examination, 7 (1.8%) were positive for culture, and 13 (3.4%) for TVK3/7, 15 (3.9%) for TV16Sf/r, and TFR1/2 17 (4.4%) were positive for PCR. Sensitivities of PCR using TFR1/2, TV16Sf/r, and TVK3/7 primer sets were 100%, 88.20%, and 76.50%, respectively, against the expanded gold standard. Trichomoniasis was associated with age above 36 (p = 0.033), not using condoms in last three months (p = 0.016), multiple sex partners (p = 0.001), reason for attendance (p = 0.027), symptomatic nature (p = 0.015), and the presence of other sexually transmitted diseases (p = 0.001).

CONCLUSIONS

The study highlighted that age over 36 years, multiple sex partners, not using condoms, reason for attendance, symptomatic nature, and having other sexually transmitted diseases can increase the risk of acquiring trichomoniasis. Furthermore, this study confirmed PCR as highly sensitive and specific diagnostic test for the diagnosis of trichomoniasis in comparison to microscopy and culture methods.

Molecular Epidemiologic Study of Male Trichomoniasis in Hamadan, Western Iran

Background:

Trichomoniasis, caused by Trichomonas vaginalis protozoan, may lead to clinical or subclinical urethritis or prostatitis in men. Despite the importance of men in the epidemiology of trichomoniasis, there is little information about this topic. This epidemiological study was performed on men in Hamedan, western Iran.

Methods:

During Oct 2018 to Mar 2019, 214 male individuals, presenting to the Urology Clinic of Shahid Beheshti Hospital in Hamadan, were enrolled and evaluated for trichomoniasis. First-voided urine specimen was used for detection of T. vaginalis infection using molecular and parasitological methods.

Results:

Trichomoniasis was detected in 10 of 214 male participants (4.7%, 95% CI: 7.5–1.8%) using PCR assay. Culture and wet mount preparation of urine sediment were unable to isolates any T. vaginalis parasite. Nine of the 10 infected men were married, and six of them were ≥49 yr of age. Urinary frequency and dysuria were the most complaints (80%) among infected individuals.

Conclusion:

Given the notable prevalence of the infection, the prevalence of male trichomoniasis will be underestimated if only conventional diagnostic methods are used. Therefore, the risk of infection as well as the molecular survey of T. vaginalis infection should be considered in men with or without clinical symptoms.

Long-term consequences of sexually transmitted infections on men's sexual function: A systematic review

Objective: To systematically review the available literature on the long-term effects of sexually transmitted diseases (STIs) on male reproductive functions.

Methods: A PubMed search was conducted on 3 January 2021, and as a result, 952 articles were retrieved. Exclusion of irrelevant articles resulted in 36 articles, dating from 1998 to 2020, which were analysed.

Results: Only 52.8% of these articles described original research, while the rest were reviews. The majority (26) of the articles dealt with bacterial infections, of which 20 described Chlamydia trachomatis. There were 11 articles that described research on viruses, with five on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The analysis of the articles showed further that not much new knowledge on the long-term effects on male reproductive functions has been added. The existing knowledge that ascending infections can cause epididymo-orchitis, prostatitis or urethritis was confirmed. Due to epithelial inflammatory responses these infections can result in scarring with resulting infertility due to obstruction. These effects were described for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium or Treponema pallidum, as well as for the Zika and SARS-CoV-2 viruses. Even trichomoniasis can lead to long-term compromised male fertility if not treated.

Conclusion: In conclusion, problem awareness needs to be raised and more research on this important topic needs to be conducted.

A review on Trichomonas vaginalis infections in women from Africa

Background

Trichomoniasis is the most common sexually transmitted infection (STI) with an estimated annual incidence of 276.4 million cases globally and about 30 million cases in sub-Saharan Africa. Trichomoniasis has been found to be associated with various health complications including pelvic inflammatory disease (PID), significant pregnancy complications, cervical cancer, prostatitis, infertility and the acquisition of human immunodeficiency virus (HIV).

Aim

Despite being a highly prevalent infection in the African continent, there is no review article published that solely focusses on Trichomonas vaginalis (T. vaginalis) infections in women from Africa. This review aims to fill this gap in the literature.

Method

An electronic search of online databases was used to identify and extract relevant research articles related to the epidemiology, health complications and treatment associated with T. vaginalis in women from Africa.

Results

Within the African continent, South Africa has reported the highest prevalence rate for this infection. A combination of sociodemographic, behavioural and biological factors has been shown to be associated with infection. Trichomonas vaginalis infection is associated with the acquisition of HIV, cervical cancer and PIDs in various female populations across the continent. Emerging patterns of resistance to metronidazole have been reported in women from South Africa. Currently, there is no effective vaccine against this pathogen despite efforts at vaccine development.

Conclusion

Based on the high prevalence and health consequences associated with T. vaginalis, there is a need for improved screening programmes that will lead to early diagnosis, detection of asymptomatic infections and effective treatment regimens.

A systematic review of Trichomonas vaginalis in Turkey from 2002 to 2020

Trichomonas vaginalis is a flagellate human parasite responsible for the most common non-viral sexually transmitted infection (STI) in the world. We aim to estimate the prevalence and basic characteristics of T. vaginalis infection in the Turkish population from 2002 to 2020. Six international and two national electronic databases were searched using keywords of "Trichomonas vaginalis" and "Turkey" both in English and Turkish languages. Searching motors for the present study included the following: Google Scholar, PubMed, Scopus, Mendeley, Science Direct, Proquest, Web of Science, YOKtez, and TRDizin. This review includes cross-sectional studies estimating the prevalence of T. vaginalis infection in the Turkish general population. If it meets the criteria for inclusion, the full-text article was obtained and reviewed. The basic characteristics of each paper were extracted and listed. Overall, 65 articles were found about T. vaginalis infection in the general Turkish population in this period. Overall, the mean prevalence of infection was found to be 5.94%, 2.87% in men, and 6.17% in women. The maximum prevalence rates were 42.4% in bar girls, 28.3% in patients with gynecological complaints, 28% in patients applied to gynecology clinics, and 15.37% in patients with vaginal discharge. Among the regions, the highest rate of infection was in the Black Sea (8.76%) and Eastern Anatolia (8.12%). In most of the studies, DM and culture methods were applied together, and the specificity of the culture method was found to be higher. Although the superiority of culture over DM is obvious, both methods can give false negativity. T. vaginalis is still an important health problem among the Turkish population. The prevalence varies depending on the socioeconomic structure of the region, the lifestyle of the person, the method used in the study, the size of the population, and the clinical condition of patients.

DFT Study and Antiparasitic Activity of Some Azo Dyes Containing Uracil

In this study, for the first time, molecular modeling and antiparasitic activity studies were carried out on some azo dyes containing uracil, 6-amino-5-[(4-nitrophenyl) diazenyl] pyrimidine-2,4 (1H, 3H)-dione (dye I) and 6-amino-5-[(4-bromophenyl) diazenyl] pyrimidin-2,4 (1H, 3H)-dione (dye II), which were resynthesized using the same method in the literature and whose molecular structures were confirmed using FTIR and 1H-NMR methods. In molecular modeling study, all calculations were performed using DFT/B3LYP/6-311++G(d,p) method. The molecular structures of the possible tautomeric forms of dyes I and II were optimized, and their molecular total energies were calculated in the gas phase and DMSO solvent. IR and 1H-NMR spectral data of the possible tautomeric forms of dyes were obtained, and theoretical spectral data were compared with experimental ones. The evaluations show that, for both dyes, the spectral data of the imine-diketo-hydrazone form, which has the lowest energy and is hence determined to be the most stable form, are in agreement with the experimental ones. In antiparasitic activity study, dyes I and II were tested for the first time against parasites Leishmania infantum, Leishmania major, Leishmania tropica promastigotes, and Trichomonas vaginalis trophozoites. In vitro antileishmanial activities against Leishmania promastigotes were tested by microdilution broth assay with Alamar Blue in RPMI 1640 medium, and in vitro trichomonacidal activities against Trichomonas vaginalis parasite were tested using TYM medium. In tests, antileishmanial and trichomonacidal effects were determined by comparing the obtained minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) values with those obtained for standard drugs (amphotericin B and metronidazole, respectively).

Trichomonas vaginalis infection impairs anion secretion in vaginal epithelium

Trichomonas vaginalis is a common protozoan parasite, which causes trichomoniasis associated with severe adverse reproductive outcomes. However, the underlying pathogenesis has not been fully understood. As the first line of defense against invading pathogens, the vaginal epithelial cells are highly responsive to environmental stimuli and contribute to the formation of the optimal luminal fluid microenvironment. The cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel widely distributed at the apical membrane of epithelial cells, plays a crucial role in mediating the secretion of Cl⁻ and HCO₃⁻. In this study, we investigated the effect of T. vaginalis on vaginal epithelial ion transport elicited by prostaglandin E₂ (PGE₂), a major prostaglandin in the semen. Luminal administration of PGE₂ triggered a remarkable and sustained increase of short-circuit current (I_SC) in rat vaginal epithelium, which was mainly due to Cl⁻ and HCO₃⁻ secretion mediated by the cAMP-activated CFTR. However, T. vaginalis infection significantly abrogated the I_SC response evoked by PGE₂, indicating impaired transepithelial anion transport via CFTR. Using a primary cell culture system of rat vaginal epithelium and a human vaginal epithelial cell line, we demonstrated that the expression of CFTR was significantly down-regulated after T. vaginalis infection. In addition, defective Cl⁻ transport function of CFTR was observed in T. vaginalis-infected cells by measuring intracellular Cl⁻ signals. Conclusively, T. vaginalis restrained exogenous PGE₂-induced anion secretion through down-regulation of CFTR in vaginal epithelium. These results provide novel insights into the intervention of reproductive complications associated with T. vaginalis infection such as infertility and disequilibrium in vaginal fluid microenvironment.

Trichomonas vaginalis is a common sexually transmitted parasite that colonized the urogenital mucosa and causes trichomoniasis, a neglected sexually transmitted infection associated with multiple adverse reproductive outcomes in humans. However, the underlying mechanisms remain largely unknown. The epithelial cystic fibrosis transmembrane conductance regulator (CFTR) is an anion channel conducting both Cl⁻ and HCO₃⁻, which participates in the regulation of luminal fluid microenvironment conducive to the success of reproductive events. Prostaglandin E₂ (PGE₂), a bioactive molecule abundant in human seminal fluid, has been demonstrated to exhibit a robust pro-secretory action by activating CFTR in the female genital tract epithelial cells such as endometrial epithelium. These discoveries motivated the authors to investigate the effect of T. vaginalis infection on exogenous PGE₂-induced transepithelial transport of electrolytes in vagina. Here, we found that in rat vaginal epithelium, luminal administration of PGE₂ elicited a response of Cl⁻ and HCO₃⁻ secretion mediated by cAMP-activated CFTR. However, T. vaginalis infection impaired transepithelial anion transport evoked by PGE₂, which is probably related to the defective expression and function of CFTR. These outcomes may complement and expand our knowledge of the complex interaction between T. vaginalis and the infected host, providing a novel therapeutic strategy for disequilibrium in vaginal fluid microenvironment and infertility induced by T. vaginalis infection.

Atomic Structure of the Trichomonas vaginalis Double-Stranded RNA Virus 2

Trichomonas vaginalis viruses (TVVs) are double-stranded RNA (dsRNA) viruses that cohabitate in Trichomonas vaginalis, the causative pathogen of trichomoniasis, the most common nonviral sexually transmitted disease worldwide. Featuring an unsegmented dsRNA genome encoding a single capsid shell protein (CSP), TVVs contrast with multisegmented dsRNA viruses, such as the diarrhea-causing rotavirus, whose larger genome is split into 10 dsRNA segments encoding 5 unique capsid proteins.

Trichomonas vaginalis, the causative pathogen for the most common nonviral sexually transmitted infection worldwide, is itself frequently infected with one or more of the four types of small double-stranded RNA (dsRNA) Trichomonas vaginalis viruses (TVV1 to 4, genus Trichomonasvirus, family Totiviridae). Each TVV encloses a nonsegmented genome within a single-layered capsid and replicates entirely intracellularly, like many dsRNA viruses, and unlike those in the Reoviridae family. Here, we have determined the structure of TVV2 by cryo-electron microscopy (cryoEM) at 3.6 Å resolution and derived an atomic model of its capsid. TVV2 has an icosahedral, T = 2*, capsid comprised of 60 copies of the icosahedral asymmetric unit (a dimer of the two capsid shell protein [CSP] conformers, CSP-A and CSP-B), typical of icosahedral dsRNA virus capsids. However, unlike the robust CSP-interlocking interactions such as the use of auxiliary “clamping” proteins among Reoviridae, only lateral CSP interactions are observed in TVV2, consistent with an assembly strategy optimized for TVVs’ intracellular-only replication cycles within their protozoan host. The atomic model reveals both a mostly negatively charged capsid interior, which is conducive to movement of the loosely packed genome, and channels at the 5-fold vertices, which we suggest as routes of mRNA release during transcription. Structural comparison of TVV2 to the Saccharomyces cerevisiae L-A virus reveals a conserved helix-rich fold within the CSP and putative guanylyltransferase domain along the capsid exterior, suggesting conserved mRNA maintenance strategies among Totiviridae. This first atomic structure of a TVV provides a framework to guide future biochemical investigations into the interplay between Trichomonas vaginalis and its viruses.

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.

Biochemical and structural characterisation of a protozoan beta-carbonic anhydrase from Trichomonas vaginalis

We report the biochemical and structural characterisation of a beta-carbonic anhydrase (β-CA) from Trichomonas vaginalis, a unicellular parasite responsible for one of the world’s leading sexually transmitted infections, trichomoniasis. CAs are ubiquitous metalloenzymes belonging to eight evolutionarily divergent groups (α, β, γ, δ, ζ, η, θ, and ι); humans express only α-CAs, whereas many clinically significant pathogens express only β- and/or γ-CAs. For this reason, the latter two groups of CAs are promising biomedical targets for novel antiinfective agents. The β-CA from T. vaginalis (TvaCA1) was recombinantly produced and biochemically characterised. The crystal structure was determined, revealing the canonical dimeric fold of β-CAs and the main features of the enzyme active site. The comparison with the active site of human CA enzymes revealed significant differences that can be exploited for the design of inhibitors selective for the protozoan enzyme with respect to the human ones.

Gardnerella vaginalis and Trichomonas vaginalis infections as risk factors for persistence and progression of low-grade precancerous cervical lesions in HIV-1 positive women

Gardnerella vaginalis (GV) and Trichomonas vaginalis (TV) infections have been proposed as risk factors for persistence and/or progression of low-grade cervical precancerous lesions (CIN1/L-SIL). In patients with Human Immunodeficiency Virus (HIV), who have an increased baseline risk of CIN1/L-SIL progression, the role of GV and TV is undefined. We aimed to investigate the prognostic impact of GV and TV infections on CIN1/L-SIL in HIV-positive women. HIV-1-positive women with L-SIL were retrospectively included. The risk of persistence or progression in the case of any infection (primary outcome), only GV (GV+), only TV (TV+), or GV and TV coinfection (secondary outcomes) was calculated compared to women with no GV or TV infections (NI), by using relative risk (RR) and multivariate logistic regression, with a significant p-value>0.05;. One hundred and ninety-two patients were included (18.2 %GV+, 15.6 %TV+, 5.2 % coinfection, 60.9 %NI); 58 CIN1/L-SIL showed persistence and 46 progression. RR for persistence/progression of CIN1/L-SIL in the case of any infection was 1.56 (1.21-2.01; p = 0.0006) compared to NI. RR for persistence alone was 1.91 (1.25-2.09; p = 0.0026) in GV+, 1.2 (0.63-2.3; p = 0.5736) in TV+, and 2.06 (1.09-3.9; p = 0.0254) in coinfection. RR for progression alone was 1.94 (1.06-3.4; p = 0.0311) in GV+, 2.14 (1.25-3.67; p = 0.0058) in TV+, and 2.73 (1.39-5.37; p = 0.0036) in coinfection. On multivariate analysis, the presence of any infection was significantly associated with persistence/progression (p = 0.002), GV + with persistence (p = 0.019) and TV + with progression (p = 0.016). In conclusion, GV infection is a risk factor for persistence of CIN1/L-SIL in HIV-positive women, while TV infection is a risk factor for progression. Women with these infections may require a closer and more careful follow-up of CIN1/L-SIL.

Paradigms of Protist/Bacteria Symbioses Affecting Human Health: Acanthamoeba species and Trichomonas vaginalis

Ever since the publication of the seminal paper by Lynn Margulis in 1967 proposing the theory of the endosymbiotic origin of organelles, the study of the symbiotic relationships between unicellular eukaryotes and prokaryotes has received ever-growing attention by microbiologists and evolutionists alike. While the evolutionary significance of the endosymbiotic associations within protists has emerged and is intensively studied, the impact of these relationships on human health has been seldom taken into account. Microbial endosymbioses involving human eukaryotic pathogens are not common, and the sexually transmitted obligate parasite Trichomonas vaginalis and the free-living opportunistic pathogen Acanthamoeba represent two unique cases in this regard, to date. The reasons of this peculiarity for T. vaginalis and Acanthamoeba may be due to their lifestyles, characterized by bacteria-rich environments. However, this characteristic does not fully explain the reason why no bacterial endosymbiont has yet been detected in unicellular eukaryotic human pathogens other than in T. vaginalis and Acanthamoeba, albeit sparse and poorly investigated examples of morphological identification of bacteria-like microorganisms associated with Giardia and Entamoeba were reported in the past. In this review article we will present the body of experimental evidences revealing the profound effects of these examples of protist/bacteria symbiosis on the pathogenesis of the microbial species involved, and ultimately their impact on human health.

Effect of a novel herbal vaginal suppository containing myrtle and oak gall in the treatment of vaginitis: a randomized clinical trial

BACKGROUND

Uncomplicated infections such as candidiasis, bacterial vaginosis (BV), or trichomoniasis are easy to diagnose and treat. However, about 8% of patients will have a more complicated course with failure to respond to treatment or rapid recurrence of symptoms. There are many suggestions in Traditional Persian Medicine like myrtle (Myrtus communis L.) and oak gall (Quercus infectoria G.Olivier) for treatment of vaginitis.

OBJECTIVES

A clinical trial was designed to assess the efficacy of a novel herbal suppository, containing myrtle and oak gall (MOGS) in treatment of vaginitis.

METHODS

In a parallel randomized clinical trial, 120 women with vaginitis were randomly assigned to MOGS, metronidazole, or placebo. Formulation was simulated from traditional Persian manuscripts and MGOS was prepared after pharmaceutical optimization processing as well as quantification of gallic acid by HPLC. The study was double-blind for MOGS and placebo and single-blind for metronidazole group.

RESULTS

MOGS effectively improved vaginal discharge (p = 0.024 for BV and 0.018 for trichomoniasis) and pH (compared to placebo (p = 0.013) and metronidazole (p = 0.001)). Both MOGS and metronidazole could reverse whiff test. Metronidazole was the best medication for making Nugent score negative (p = 0.005) as well as the best therapy according to laboratory findings to treat BV in comparison with placebo (p = 0.021). While for trichomoniasis, MOGS could improve the disease more successfully (p = 0.001). Both MOGS and metronidazole treated mixed vaginitis (p = 0.002).

CONCLUSION

MOGS would be a chance for developing new treatment for trichomoniasis.

Molecular Targets Implicated in the Antiparasitic and Anti-Inflammatory Activity of the Phytochemical Curcumin in Trichomoniasis

Trichomoniasis, is the most prevalent non-viral sexually transmitted disease worldwide. Although metronidazole (MDZ) is the recommended treatment, several strains of the parasite are resistant to MDZ, and new treatments are required. Curcumin (CUR) is a polyphenol with anti-inflammatory, antioxidant and antiparasitic properties. In this study, we evaluated the effects of CUR on two biochemical targets: on proteolytic activity and hydrogenosomal metabolism in Trichomonas vaginalis. We also investigated the role of CUR on pro-inflammatory responses induced in RAW 264.7 phagocytic cells by parasite proteinases on pro-inflammatory mediators such as the nitric oxide (NO), tumor necrosis factor α (TNFα), interleukin-1beta (IL-1β), chaperone heat shock protein 70 (Hsp70) and glucocorticoid receptor (mGR). CUR inhibited the growth of T. vaginalis trophozoites, with an IC₅₀ value between 117 ± 7 μM and 173 ± 15 μM, depending on the culture phase. CUR increased pyruvate:ferredoxin oxidoreductase (PfoD), hydrogenosomal enzyme expression and inhibited the proteolytic activity of parasite proteinases. CUR also inhibited NO production and decreased the expression of pro-inflammatory mediators in macrophages. The findings demonstrate the potential usefulness of CUR as an antiparasitic and anti-inflammatory treatment for trichomoniasis. It could be used to control the disease and mitigate the associated immunopathogenic effects.

Gardnerella vaginalis and Trichomonas vaginalis infections and the risk of persistence or progression of low-grade cervical intraepithelial neoplasia

Gardnerella vaginalis (GV) and Trichomonas vaginalis (TV) infections have been proposed as risk factors for persistence or progression of low-grade precancerous cervical lesions (CIN1/L-SIL). However, their role is still undefined. We aimed to assess if GV and TV infections affect the risk of persistence/progression of CIN1/L-SIL. A retrospective cohort study was performed to assess the risk of CIN1/L-SIL persistence or progression, persistence alone and progression alone in patients with GV and/or TV infections (GV + and/or TV+), only GV (GV+), only TV (TV+), or GV and TV coinfections compared to patients without these infections. Relative risk (RR) with 95 % confidence intervals (CI) was adopted (significant p-value>0.05). Two hundred and seventy patients were included. RR for CIN1/L-SIL persistence or progression was 1.63 in GV + and/or TV+ (p = 0.02), 1.99 in GV+ (p = 0.0008), 0.25 in TV+ (p = 0.32), 1.78 in coinfection (p = 0.26). RR for persistence was 1.55 in GV + and/or TV+ (p = 0.1), 2.179 in GV+ (p = 0.0013), 0.32 in TV+ (p = 0.41), 0.45 in coinfection (p = 0.55). RR for progression was 1.92 in GV + and/or TV+ (p = 0.22), 1.34 in GV+ (p = 0.68), 1.16 in TV+ (p = 0.91), 8.39 in coinfection (p = 0.0002). In conclusion, GV infection may be a risk factor for CIN1/L-SIL persistence. TV infection alone does not significantly affect the risk of persistence or progression of such lesions, while it may greatly increase the risk of progression when associated with GV infection.

The First Detection of Co-Infection of Double-Stranded RNA Virus 1, 2 and 3 in Iranian Isolates of Trichomonas vaginalis

Background

The Totiviridae family includes a number of double-stranded RNA viruses that can infect Trichomonas vaginalis. Some T. vaginalis isolates are infected with one or more double-stranded RNA (dsRNA) viruses. In this study, different strains of double-stranded RNA virus in Iranian isolates of T. vaginalis were evaluated for the first time in Iran.

Methods

Vaginal swabs were collected from 1550 participants who were referred to hospitals associated with Iran University of Medical Sciences, Tehran, Iran from June to November 2018. T. vaginalis isolates were cultured in Diamond's modified medium. After the extraction of nucleic acids using a DNA/RNA extraction kit, RT-PCR was performed and PCR products were purified and sequenced.

Results

In general 9 (0.6%) isolates were confirmed as T. vaginalis among 1550 collected vaginal samples. Among 9 isolates of T. vaginalis, three of them were infected with TVV1. One isolate has multiple infections with T. vaginalis virus (TVV1, TVV2 and TVV3) as coinfection. The nucleotide BLAST indicated that the T. vaginalis virus 1(TVV1) isolates were most closely related to TVV1-OC5, TVV1-UR1-1.The T. vaginalis virus 2 (TVV2) sequence had also a similarity with TVV2-UR1-1, TVV2-UR1 and TVV2-OC3. The sequence of T. vaginalis virus 3(TVV3) had similarity with TVV3-OC5, TVV3-UR1-1 and TVV3-UR1.

Conclusion

Three dsRNA viruses T. vaginalis virus (TVV1, TVV2 and TVV3) were detected using RT-PCR in T. vaginalis Iranian isolates. The coinfection of TVV1, TVV2 and TVV3 in one isolate of T.vaginalis was observed for the first time in Iran.

Protein cysteine S-nitrosylation provides reducing power by enhancing lactate dehydrogenase activity in Trichomonas vaginalis under iron deficiency

BACKGROUND

Iron plays essential roles in the pathogenesis and proliferation of Trichomonas vaginalis, the causative agent of the most prevalent non-viral human sexually transmitted infection. We previously demonstrated that under iron deficiency, the endogenous nitric oxide (NO) is accumulated and capable of regulating the survival of T. vaginalis. Herein, we aim to explore the influence of NO on the activity of the pyruvate-reducing enzyme lactate dehydrogenase in T. vaginalis (TvLDH).

METHODS

Levels of lactate and pyruvate were detected for determining glycolysis activity in T. vaginalis under iron deficiency. Quantitative PCR was performed to determine the expression of TvLDH. S-nitrosylated (SNO) proteomics was conducted to identify the NO-modified proteins. The activities of glyceraldehyde-3-phosphate dehydrogenase (TvGAPDH) and TvLDH were measured after sodium nitrate treatment. The effects of protein nitrosylation on the production of cellular reducing power were examined by measuring the amount of nicotinamide adenine dinucleotide (NAD) and the ratio of the NAD redox pair (NAD+/NADH).

RESULTS

We found that although the glycolytic pathway was activated in cells under iron depletion, the level of pyruvate was decreased due to the increased level of TvLDH. By analyzing the SNO proteome of T. vaginalis upon iron deficiency, we found that TvLDH is one of the glycolytic enzymes modified by SNO. The production of pyruvate was significantly reduced after nitrate treatment, indicating that protein nitrosylation accelerated the consumption of pyruvate by increasing TvLDH activity. Nitrate treatment also induced NAD oxidation, suggesting that protein nitrosylation was the key posttranslational modification controlling cellular redox status.

CONCLUSIONS

We demonstrated that NO-mediated protein nitrosylation plays pivotal roles in the regulation of glycolysis, pyruvate metabolism, and the activity of TvLDH. The recycling of oxidized NAD catalyzed by TvLDH provided the reducing power that allowed T. vaginalis to adapt to the iron-deficient environment.

Trichomonas vaginalis Virus Among Women With Trichomoniasis and Associations With Demographics, Clinical Outcomes, and Metronidazole Resistance

BACKGROUND

Trichomonas vaginalis virus (TVV) is a non-segmented, 4.5-5.5 kilo-base pair (kbp), double-stranded RNA virus infecting T. vaginalis. The objectives of this study were to examine the TVV prevalence in US Trichomonas vaginalis isolates and TVV's associations with patient demographics, clinical outcomes, and metronidazole resistance.

METHODS

Archived T. vaginalis isolates from the enrollment visits of 355 women participating in a T. vaginalis treatment trial in Birmingham, Alabama, were thawed and grown in culture. Their total RNA was extracted using a Trizol reagent. Contaminating, single-stranded RNA was precipitated using 4.0 M Lithium Chloride and centrifugation. The samples were analyzed by gel electrophoresis to visualize a 4.5 kbp band representative of TVV. In vitro testing for metronidazole resistance was also performed on 25/47 isolates obtained from the women's test of cure visits.

RESULTS

TVV was detected in 142/355 (40%) isolates at the enrollment visit. Women with TVV-positive (TVV+) isolates were significantly older (P = .01), more likely to smoke (P = .04), and less likely to report a history of gonorrhea (P = .04). There was no association between the presence of clinical symptoms or repeat T. vaginalis infections with TVV+ isolates (P = .14 and P = .44, respectively). Of 25 test of cure isolates tested for metronidazole resistance, 0/10 TVV+ isolates demonstrated resistance, while 2/15 TVV-negative isolates demonstrated mild to moderate resistance (P = .23).

CONCLUSIONS

Of 355 T. vaginalis isolates tested for TVV, T. vaginalis isolates tested for TVV, the prevalence was 40%. However, there was no association of TVV+ isolates with clinical symptoms, repeat infections, or metronidazole resistance. These results suggest that TVV may be commensal to T. vaginalis.

Neutrophil interactions with the sexually transmitted parasite Trichomonas vaginalis: implications for immunity and pathogenesis

Trichomoniasis is the third most common sexually transmitted infection in humans and is caused by the protozoan parasite, Trichomonas vaginalis (Tv). Pathogenic outcomes are more common in women and generally include mild vaginitis or cervicitis. However, more serious effects associated with trichomoniasis include adverse reproductive outcomes. Like other infectious agents, pathogenesis from Tv infection is predicted to be the result of both parasite and host factors. At the site of infection, neutrophils are the most abundant immune cells present and probably play key roles in both parasite clearance and inflammatory pathology. Here, we discuss the evidence that neutrophils home to the site of Tv infection, kill the parasite, and that in some circumstances, parasites possibly evade neutrophil-directed killing. In vitro, the parasite is killed by neutrophils using a novel antimicrobial mechanism called trogocytosis, which probably involves both innate and adaptive immunity. While mechanisms of evasion are mostly conjecture at present, the persistence of Tv infections in patients argues strongly for their existence. Additionally, many strains of Tv harbour microbial symbionts Mycoplasma hominis or Trichomonasvirus, which are both predicted to impact neutrophil responses against the parasite. Novel research tools, especially animal models, will help to reveal the true outcomes of many factors involved in neutrophil-Tv interactions during trichomoniasis.

Scientometric Analysis of Global Research on Trichomoniasis in Scopus Database (1922 -2018)

BACKGROUND

Trichomoniasis is a sexually transmitted disease (STD) prevalent in different parts of the world. The present study was designed to evaluate the scientific output and collaboration of researchers worldwide on trichomoniasis.

METHODS

In the present scientometric research, all papers conducted on Trichomonas vaginalis (T. vaginalis) published in the time period of 1922 to 2018 were extracted from the Scopus database and evaluated according to the aims of the research, using scientometric software.

RESULTS

The results of this search strategy were the retrieval of 12,596 scientific papers authored by a total of 28,822 people during 97 years (1922-2018). Research in this field has encountered success and failure over the years. The first article on trichomoniasis at the Scopus database was published by Musgrave W.E. (1922) in the "Journal of the American Medical Association". Most papers on this subject (352) were published in 2013; and the years 2017 and 2016 are ranked second and third. Researchers from the US Centers for Disease Control and Prevention have the highest number of papers in this field (210). Alderete J.F. with 111 papers is the most active researcher on trichomoniasis in Scopus. Also, researchers from the US ranked the first with 3,236 papers. In Iran, by the end of 2018, 138 papers on trichomoniasis have been registered in Scopus, which accounts for only one percent of the world's science production in this field.

DISCUSSION AND CONCLUSION

The results following about one century indicated that the number of publications on T. vaginalis is growing and that there is a high level of collaboration among researchers in this field. Moreover, many countries have collaborated internationally on trichomoniasis research with the US as the leading country.

Update on the Diagnosis of Sexually Transmitted Infections

Sexually transmitted infections (STIs) are one of the most frequent and universal Public Health problems. Health professionals should be aware of the possibility of STIs due to their high morbidity and the presence of sequelae. The delay in the diagnosis is one of the factors that justifies the difficulty to infections control. Diagnostic tests allow the introduction of aetiological treatment and also lead to treating symptomatic and asymptomatic patients more effectively, as well as to interrupt the epidemiological transmission chain without delay. In this review we have made an update of the main existing diagnostic methods for the more important STIs.

Correlates of trichomoniasis among female sex workers who inject drugs in two Mexico-US border cities

This paper evaluates correlates of trichomoniasis among female sex workers who inject drugs (FSWIDs) in two Mexico-US border cities. HIV-negative FSWIDs aged 18 years or older were enrolled in a study between 2008 and 2010 in Tijuana and Ciudad Juarez (Cd.), Mexico. All participants underwent a baseline interviewer-administered survey and did a rapid test for trichomoniasis. Using regression to estimate prevalence ratios, we examined sociodemographics, sex work characteristics, sexual health and behavior, substance use, and police and violence exposures as potential correlates of trichomoniasis. Of 584 women (284 in Tijuana, 300 in Cd. Juarez), prevalence of trichomoniasis was 33.6%. Factors associated with trichomoniasis in multivariable analysis were having money stolen by police in the past six months (adjusted prevalence ratio [aPR] =1.448, 95% confidence interval [CI] = 1.152-1.821), recent methamphetamine use (aPR = 1.432, CI = 1.055-1.944), lifetime syphilis infection (aPR = 1.360, CI = 1.061-1.743), ever use of a home remedy to treat vaginal symptoms (aPR = 1.301, CI = 1.027-1.649), and number of regular clients in the past month (aPR = 1.006 per client, CI = 1.004-1.009), while controlling for age and city of interview. Alongside the need for trichomoniasis surveillance and treatment programs, findings indicate that both structural and behavioral factors serve as primary correlates of trichomoniasis among FSWIDs in these cities.