Trichomonas vaginalis: a review of epidemiologic, clinical and treatment issues

Prevalence of Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Mycoplasma genitalium and risk factors among pregnant women in Brazil: Results from the national molecular diagnosis implementation project

BACKGROUND

Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil.

METHODS

A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included.

RESULTS

A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86).

CONCLUSION

This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.

Structures of Native Doublet Microtubules from Trichomonas vaginalis Reveal Parasite-Specific Proteins as Potential Drug Targets

Doublet microtubules (DMTs) are flagellar components required for the protist Trichomonas vaginalis ( Tv ) to swim through the human genitourinary tract to cause trichomoniasis, the most common non-viral sexually transmitted disease. Lack of DMT structures has prevented structure-guided drug design to manage Tv infection. Here, we determined the cryo-EM structure of native Tv- DMTs, identifying 29 unique proteins, including 18 microtubule inner proteins and 9 microtubule outer proteins. While the A-tubule is simplistic compared to DMTs of other organisms, the B-tubule features specialized, parasite-specific proteins, like Tv FAP40 and Tv FAP35 that form filaments near the inner and outer junctions, respectively, to stabilize DMTs and enable Tv locomotion. Notably, a small molecule, assigned as IP6, is coordinated within a pocket of Tv FAP40 and has characteristics of a drug molecule. This first atomic model of the Tv -DMT highlights the diversity of eukaryotic motility machinery and provides a structural framework to inform the rational design of therapeutics.

Imidazole Carbamates as a Promising Alternative for Treating Trichomoniasis: In Vitro Effects on the Growth and Gene Expression of Trichomonas vaginalis

Metronidazole (MTZ) is the most common drug used against Trichomonas vaginalis (T. vaginalis) infections; however, treatment failures and high rates of recurrence of trichomoniasis have been reported, suggesting the presence of resistance in T. vaginalis to MTZ. Therefore, research into new therapeutic options against T. vaginalis infections has become increasingly urgent. This study investigated the trichomonacidal activity of a series of five imidazole carbamate compounds (AGR-1, AGR-2, AGR-3, AGR-4, and AGR-5) through in vitro susceptibility assays to determine the IC50 value of each compound. All five compounds demonstrated potent trichomonacidal activity, with IC50 values in the nanomolar range and AGR-2 being the most potent (IC50 400 nM). To gain insight into molecular events related to AGR-induced cell death in T. vaginalis, we analyzed the expression profiles of some metabolic genes in the trophozoites exposed to AGR compounds and MTZ. It was found that both AGR and MTZ compounds reduced the expression of the glycolytic genes (CK, PFK, TPI, and ENOL) and genes involved in metabolism (G6PD, TKT, TALDO, NADHOX, ACT, and TUB), suggesting that disturbing these key metabolic genes alters the survival of the T. vaginalis parasite and that they probably share a similar mechanism of action. Additionally, the compounds showed low cytotoxicity in the Caco-2 and HT29 cell lines, and the results of the ADMET analysis indicated that these compounds have pharmacokinetic properties similar to those of MTZ. The findings offer significant insights that can serve as a basis for future in vivo studies of the compounds as a potential new treatment against T. vaginalis.

Asymptomatic infections with Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis among women in low- and middle-income countries: A systematic review and meta-analysis

Syndromic management of sexually transmitted infections (STIs) is common in settings with limited access to diagnostic testing. However, this approach does not capture asymptomatic STIs. Untreated asymptomatic infections may result in serious complications and sequelae in women. We aimed to estimate the proportion and the prevalence of asymptomatic Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), and Trichomonas vaginalis (TV) infections among women in low- and middle-income countries. We searched Medline, Scopus, and Web of Science for articles published between 2000 and 2022. We used random effect models to compute the proportion and prevalence estimates and performed sub-group analysis. We evaluated the quality of each article using the Appraisal tool for Cross-Sectional Studies and performed sensitivity analyses. This study was registered with PROSPERO, CRD42022286673. Forty-eight eligible studies were included. The proportion of asymptomatic CT, NG, and TV infections were: 60.7% [95% Confidence Interval (CI): 50.4; 70.5], 53.3% [37.1; 69.1], and 56.9% [44.6; 68.9], respectively. The proportion of women with asymptomatic infections was the highest in Africa for the three pathogens. The pooled prevalence of asymptomatic CT, NG, and TV infection was 4.70 per 100 women [95%CI: 3.39; 6.20], 3.11 [1.34; 5.54], and 5.98 [3.46; 9.12], respectively. More than half of the women infected by CT, NG, or TV were asymptomatic. To avoid undiagnosed and untreated asymptomatic infections leading to complications, alternative approaches to syndromic management urgently need to be considered.

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

BACKGROUND

Previous studies have suggested that vitamin D may possess anti-infection properties, but the relationship between vitamin D and Trichomonas vaginalis infection remains unexplored.

METHODS

Using data from the National Health and Nutrition Examination Survey between 2013 and 2016, we conducted multivariate regression analyses and subgroup analyses to investigate the association between 25-hydroxyvitamin D (25[OH]D) levels and T. vaginalis infection, ensuring the robustness of our results.

RESULTS

The final sample included data from 4318 individuals aged 20 to 59 years, among which 92 were diagnosed with T. vaginalis infection. For every 10 nmol/L increase in serum 25(OH)D level, there was a 22% reduction in the likelihood of T. vaginalis infection incidence (adjusted odds ratio [aOR], 0.78; 95% confidence interval [CI], 0.69-0.90). Similarly, higher concentration tertiles demonstrated relatively lower infection ratios compared with the tertile with the lowest 25(OH)D concentration (aOR, 0.54 [95% CI, 0.30-0.95; P = 0.030] for T2; aOR, 0.23 [95% CI, 0.09-0.61; P < 0.001] for T3).

CONCLUSIONS

Our cross-sectional study indicates a negative association between 25(OH)D levels and the prevalence of T. vaginalis infection. However, further high-quality evidence is needed to establish a causal relationship between 25(OH)D levels and T. vaginalis infection, as well as to evaluate the potential role of vitamin D supplementation in preventing T. vaginalis infection.

The prevalence of Trichomonas vaginalis infection among the female population of Iran: a systematic review and meta-analysis

Trichomonas vaginalis is a protozoan parasite and probably one of the main causes of adverse birth outcomes. Still, there is a paucity of information regarding the burden of T. vaginalis infection in Iranian women. To address this gap, we conducted a systematic review and meta-analysis of studies on trichomoniasis among females in Iran from January 2000 to January 2023. We searched multiple electronic databases (PubMed, Science Direct, Scopus, ProQuest, Web of Science, Google Scholar, Scientific Information Database, Iran Medex, Magiran and Iran Doc) and identified 108 articles with a total of 200 728 women. Using a random effects model, we found a pooled prevalence of 4.30% (95% CI 3.23 to 5.52%). Subgroup analysis, also, demonstrated a statistically significant association between the T. vaginalis prevalence in Iranian women, and the age range, city, sample type, being in prison, sex working and symptomatic infections. Our findings provide important information for healthcare authorities and can inform prevention strategies against trichomoniasis in Iran.

Unconventional features in the transcription and processing of spliceosomal small nuclear RNAs in the protozoan parasite Trichomonas vaginalis

Trichomonas vaginalis is a medically important protozoan parasite, and a deep-branching, evolutionarily divergent unicellular eukaryote that has conserved several key features of eukaryotic gene expression. Trichomonas vaginalis possesses a metazoan/plant-like capping apparatus, mRNAs with a cap 1 structure and spliceosomes containing the five small nuclear RNAs (snRNAs). However, in contrast to metazoan and plant snRNAs, the structurally conserved T. vaginalis snRNAs were initially identified as lacking the canonical guanosine cap nucleotide. To explain this unusual condition, we sought to investigate transcriptional and processing features of the spliceosomal snRNAs in this protist. Here, we show that T. vaginalis spliceosomal snRNA genes mostly lack typical eukaryotic promoters. In contrast to other eukaryotes, the putative TATA box in the T. vaginalis U6 snRNA gene was found to be dispensable for transcription or RNA polymerase selectivity. Moreover, U6 transcription in T. vaginalis was virtually insensitive to tagetitoxin compared with other cellular transcripts produced by the same RNA polymerase III. Most important and unexpected, snRNA transcription in T. vaginalis appears to bypass capping as we show that these transcripts retain their original 5'-triphosphate groups. In conclusion, transcription and processing of spliceosomal snRNAs in T. vaginalis deviate considerably from the conventional rules of other eukaryotes.

Uncovering the diversity of pathogenic invaders: insights into protozoa, fungi, and worm infections

Post COVID-19, there has been renewed interest in understanding the pathogens challenging the human health and evaluate our preparedness towards dealing with health challenges in future. In this endeavour, it is not only the bacteria and the viruses, but a greater community of pathogens. Such pathogenic microorganisms, include protozoa, fungi and worms, which establish a distinct variety of disease-causing agents with the capability to impact the host's well-being as well as the equity of ecosystem. This review summarises the peculiar characteristics and pathogenic mechanisms utilized by these disease-causing organisms. It features their role in causing infection in the concerned host and emphasizes the need for further research. Understanding the layers of pathogenesis encompassing the concerned infectious microbes will help expand targeted inferences with relation to the cause of the infection. This would strengthen and augment benefit to the host's health along with the maintenance of ecosystem network, exhibiting host-pathogen interaction cycle. This would be key to discover the layers underlying differential disease severities in response to similar/same pathogen infection.

Exploring novel pyrazole-nitroimidazole hybrids: Synthesis and antiprotozoal activity against the human pathogen trichomonas vaginalis

Trichomoniasis, a prevalent sexually transmitted infection (STI) caused by the protozoan Trichomonas vaginalis, has gained increased significance globally. Its relevance has grown in recent years due to its association with a heightened risk of acquiring and transmitting the human immunodeficiency virus (HIV) and other STIs. In addition, many publications have revealed a potential link between trichomoniasis and certain cancers. Metronidazole (MTZ), a nitroimidazole compound developed over 50 years ago, remains the first-choice drug for treatment. However, reports of genotoxicity and side effects underscore the necessity for new compounds to address this pressing global health concern. In this study, we synthesized ten pyrazole-nitroimidazoles 1(a-j) and 4-nitro-1-(hydroxyethyl)-1H-imidazole 2, an analog of metronidazole (MTZ), and assessed their trichomonacidal and cytotoxic effects. All compounds 1(a-j) and 2 exhibited IC50 values ≤ 20 μM and ≤ 41 μM, after 24 h and 48 h, respectively. Compounds 1d (IC50 5.3 μM), 1e (IC50 4.8 μM), and 1i (IC50 5.2 μM) exhibited potencies equivalent to MTZ (IC50 4.9 μM), the reference drug, after 24 h. Notably, compound 1i showed high anti-trichomonas activity after 24 h (IC50 5.2 μM) and 48 h (IC50 2.1 μM). Additionally, all compounds demonstrated either non-cytotoxic to HeLa cells (CC50 > 100 μM) or low cytotoxicity (CC50 between 69 and 100 μM). These findings suggest that pyrazole-nitroimidazole derivatives represent a promising heterocyclic system, serving as a potential lead for further optimization in trichomoniasis chemotherapy.

Declining Prevalence of Trichomonas vaginalis Diagnosed by Wet Mount in a Cohort of U.S. Women With and Without HIV

Background: Women living with HIV (WLWH) are often coinfected with Trichomonas vaginalis (TV), and annual screening is recommended. Our goal was to assess differences in TV prevalence at study entry and over time in enrollment cohorts of the Women's Interagency HIV Study. Methods: In a multisite study, TV was diagnosed by wet mount microscopy. Prevalence was determined across four enrollment waves: 1994-1995, 2001-2002, 2011-2012, and 2013-2015. Generalized estimating equation multivariable logistic regression models assessed changes in visit prevalence across waves after controlling for HIV disease severity and other risks. Results: At 63,824 person-visits (3,508 WLWH and 1,262 women without HIV), TV was diagnosed by wet mount at 1979 visits (3.1%). After multivariable adjustment, HIV status was not associated with TV detection, which was more common among younger women, women with multiple partners, and irregular condom use. All enrollment waves showed a decline in TV detection over time, although p-value for trend did not reach significance for most recent waves. To explore the potential utility of screening among WLWH, we assessed rates of TV detection among women without appreciable vaginal discharge on examination. Initial TV prevalence among asymptomatic women was 3.5%, and prevalence decreased to 0.5%-1% in the most recent wave (2013-2015) (p-trend <0.0001). Conclusions: In this cohort, TV rates are low among WLWH, and HIV does not increase TV risk. Screening may benefit newly diagnosed WLWH, women with risk factors, or those receiving care sporadically but is unlikely to further reduce the low rate of TV among women in care, especially older women without multiple partners. The clinical trials registration number for WIHS is NCT00000797.

A Comparison of Bottom-Up Proteomic Sample Preparation Methods for the Human Parasite Trichomonas vaginalis

Bottom-up proteomic approaches depend on the efficient digestion of proteins into peptides for mass spectrometric analysis. Sample preparation strategies, based on magnetic beads, filter-aided systems, or in-solution digests, are commonly used for proteomic analysis. Time-intensive methods like filter-aided sample preparation (FASP) have led to the development of new, more time-efficient filter-based strategies like suspension trappings (S-Traps) or magnetic bead-based strategies like SP3. S-Traps have been reported as an alternative proteomic sample preparation method as they allow for high sodium dodecyl sulfate (SDS) concentrations to be present in the sample. In this study, we compare the efficiency of different protocols for FASP, SP3, and S-Trap-based digestion of proteins after extraction from Trichomonas vaginalis. Overall, we found a high number of protein IDs for all tested methods and a high degree of reproducibility within each method type. However, FASP with a 3 kDa cutoff filter unit outperformed the other methods analyzed, referring to the number of protein IDs. This is the first work providing the direct comparison of four different bottom-up proteomic approaches regarding the most efficient proteomic sample preparation protocol for the human parasite T. vaginalis.

Therapeutic potential of antimicrobial peptides against pathogenic protozoa

Protozoal infections cause significant morbidity and mortality in humans and animals. The use of several antiprotozoal drugs is associated with serious adverse effects and resistance development, and drugs that are more effective are urgently needed. Microorganisms, mammalian cells and fluids, insects, and reptiles are sources of antimicrobial peptides (AMPs) that act against pathogenic microorganisms; these AMPs have been widely studied as a promising alternative therapeutic option to conventional antibiotics, aiming to treat infections caused by multidrug-resistant pathogens. One advantage of AMP molecules is their adaptability, as they can be easily fine-tuned for broad-spectrum or targeted activity by changing the amino acid residues in their sequence. Consequently, these variations in structural and physicochemical properties can alter the antimicrobial activities of AMPs and decrease resistance development. This article presents an overview of peptide activities against amebiasis, giardiasis, trichomoniasis, Chagas disease, leishmaniasis, malaria, and toxoplasmosis. AMPs and their analogs demonstrate great potential as therapeutics, with potent and selective activity, when compared with commercially available drugs, and hold the potential to act as new scaffolds for the development of novel anti-protozoal drugs.

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.

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.

Persistent Trichomonas vaginalis infections and the pseudocyst form

Recent studies have proposed that Trichomonas vaginalis, the causative agent of trichomoniasis [the most common nonviral sexually transmitted infection (STI) in humans] can establish persistent infections in the vagina. T. vaginalis infections are often asymptomatic but can have adverse consequences such as increased risk of HIV-1 infection and cervical cancer. Despite this, it remains an understudied infection. A potential agent of persistent infections is the 'pseudocyst', a spherical form of T. vaginalis identified by several laboratories and linked to persistence in related species such as the avian parasite Trichomonas gallinae and cattle parasite Tritrichomonas foetus. Additional robust and reproducible research on pseudocysts and persistent T. vaginalis infections is required, which may ultimately shed light on how to better diagnose and treat trichomoniasis.

Evaluating the utility of the Allplex STI Essential Assay to determine the occurrence of urogenital sexually transmitted infections among symptomatic and asymptomatic patients in Cape Town, South Africa

BACKGROUND

Sexually transmitted infections are among the most commonly occurring infections globally, with countries in sub-Saharan Africa exhibiting disproportionately higher prevalence rates. Numerous reports indicate the need for accurate detection, epidemiological characterisation, and appropriate management of these infections. This prospective observational laboratory study sought to determine the occurrence of STI, using a validated molecular assay as a diagnostic and surveillance tool in our setting.

METHODS

Urogenital swabs from symptomatic and asymptomatic patients, submitted to the National Health Laboratory Service, at Groote Schuur Hospital, from 04 August 2021-03 February 2022, for routine microbiological investigations, were subjected to the Allplex™ STI Essential Assay (Seegene Inc, South Korea) to determine the distribution of STI pathogens in our setting. This multiplex assay includes C. trachomatis, Mycoplasma genitalium, Mycoplasma hominis, N. gonorrhoeae, Trichomonas vaginalis, Ureaplasma parvum, and Ureaplasma urealyticum. Correlations between detected organisms and participant age and clinical indications for testing were determined using Stata® software.

RESULTS

A total of 148 urogenital swabs (91.2% from women) were included in the analysis, of which 56/148 (37.84%) were from symptomatic patients. Up to 83.8% of the samples tested positive for ≥1 organism, with all seven target organisms detected in at least one sample. Ureaplasma parvum was the most common organism detected, followed by N. gonorrhoeae, M. hominis, U. urealyticum, T. vaginalis, C. trachomatis, with M. genitalium being the least detected. All 25 samples submitted for routine antenatal Group B Streptococcal screening were positive for at least one STI organism, and one sample from sexual non-accidental injury tested positive for five different organisms.

CONCLUSIONS

STIs comprise a variety of organisms in our setting, with many patients exhibiting coinfection with multiple organisms. This suggests the need for a critical evaluation of current syndromic testing and treatment guidelines so as to stem inadvertent spread of STI organisms and the development of resistance. The use of molecular testing methods may improve detection, especially in resource limited settings, providing speedy results, and thus allowing for guided therapy in only infected patients.

Trichomonas vaginalis infection is associated with increased risk of cervical carcinogenesis: A systematic review and meta-analysis of 470 000 patients

BACKGROUND

Trichomonas vaginalis infection is the most prevalent non-viral sexually transmitted infection (STI) in women and has been suggested as a risk factor for developing cervical cancer.

OBJECTIVE

We aimed to investigate the associations between T. vaginalis infection and cervical carcinogenesis.

SEARCH STRATEGY

A comprehensive systematic search was conducted in five databases on 21 October 2021.

SELECTION CRITERIA

Studies assessing the relationship between T. vaginalis infection, HPV co-infections, cervical dysplasia, and cervical cancer were found eligible.

DATA COLLECTION AND ANALYSIS

Summary estimates for pooled odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated with a random-effects model. Statistical heterogeneity was measured with I2 and Cochran's Q tests.

MAIN RESULTS

The 29 articles included 473 740 women, of whom 8518 were T. vaginalis-positive. Our results showed that T. vaginalis-infected women had 1.79 times higher odds of being diagnosed with HPV co-infection (95% CI 1.27-2.53; I2 95%). We also found that T. vaginalis infection was associated with high-grade squamous intraepithelial lesion diagnosis (OR 2.34, 95% CI 1.10-4.95; I2 75%) and cervical cancer (OR 5.23, 95% CI 3.03-9.04; I2 3%).

CONCLUSIONS

Our results showed an association between T. vaginalis and cervical carcinogenesis in sexually active women.

Activity of compounds derived from benzofuroxan in Trichomonasvaginalis

Trichomoniasis is a sexually transmitted infection caused by the protozoan Trichomonas vaginalis. Currently, trichomoniasis is treated with the class of nitroimidazoles, namely, metronidazole; however, resistant isolates and strains have been reported. The compounds derived from benzofuroxan are biologically active heterocycles. This study evaluated the in vitro antiparasitic activity of these compounds in trophozoites of T. vaginalis and determined the mean inhibitory concentration (IC50), minimum inhibitory concentration (MIC), mortality curve, and cytotoxicity. The compounds were named EH1, EH2, EH3, and EA2 and tested in various concentrations: 100 to 15 μM (EH1 and EH2); 100 to 5 μM (EH3); and 100 to 25 μM (EA2), respectively. The greatest efficacy was observed in the highest concentrations in 24 h, with inhibition of approximately 100% of trophozoites. Compounds EH2 and EH3 had the lowest MIC: EH2 (35 μM) and EH3 (45 μM), with IC50 of 11.33 μM and 6.83 μM, respectively. Compound EA2 was effective at the highest concentrations. The activity of the compounds in T. vaginalis started in the first hour of incubation with 90% inhibition; after 12 h, inhibition >95% was observed. Compound EH1 showed the lowest activity, with the highest activity between 12 and 24 h after incubation. These results demonstrate that benzofuroxan derivatives are promising compounds for the in vitro treatment of T. vaginalis.

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.

Prevalence of trichomoniasis infection among adults in Nigerian community settings

BACKGROUND

Trichomonas vaginalis (TV) is a sexually transmitted pathogen. The study was conducted to determine its prevalence among 300 adult patients in 4 public health facilities in the Nsukka District of Enugu State, Nigeria.

METHOD

The researchers collected high vagina swabs and urine samples were collected from 150 men and 150 women, respectively. The specimens were scrutinized for color, odor of discharge and urine, and motile trichomoniasis.

RESULTS

The prevalence of the TV was 45.0% (135/300) with women showing the highest prevalence (63.7%). Among the patients attending the University of Nigeria, Nsukka Medical Center, the prevalence was the highest at 31.9%. TV infection was more common among older adults aged 38 to 47 years (39.3%), married adults (76.3%), and those with secondary education (68.9%). Urogenital analysis reported that males with pains during urination were 51.0% and males with penile tingling were 12.2%. The highest vaginal Hydrogen ion concentration level of 6.8 was observed in women aged 38 to 47 years. Additionally, the results reported that Vaginal candidiasis, Bacterial vaginosis, and Herpes simplex virus type 2 antibodies were not independently associated with TV infection. In the unadjusted analysis, the odds of TV infection were higher in men (8.1), while Chlamydia trachomatis infection was higher in women (8.8). Among the adults diagnosed with herpes simplex virus type 2 antibodies, the odds of TV infection were 3.9 for both men and women. Men with penile human papillomavirus infection had lower odds of TV infection (1.9), while women with vaginal human papillomavirus infection had higher odds of TV infection (2.2).

CONCLUSION

The prevalence of TV infection is high among sexually active adults in the Nigerian community. It is therefore crucial to implement the increased public health actions such as regular and early diagnosis to reduce its prevalence.

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.

Disparities in adherence to retesting guidelines in women with Trichomonas vaginalis infection

BACKGROUND

Trichomoniasis is the most prevalent nonviral sexually transmitted infection in the United States. Numerous studies have shown disproportionately higher prevalence rates in non-Hispanic Black women. Because of the high rates of reinfection, the Centers for Disease Control and Prevention recommends retesting women treated for trichomoniasis. Despite these national guidelines, there are few studies examining adherence to retesting recommendations for patients with trichomoniasis. Adherence to retesting guidelines has been shown in other infections to be an important determinant of racial disparities.

OBJECTIVE

This study aimed to describe Trichomonas vaginalis infection rates, evaluate adherence to retesting guidelines, and examine characteristics of women who were not retested according to the guidelines in an urban, diverse, hospital-based obstetrics and gynecology clinic population.

STUDY DESIGN

We conducted a retrospective cohort study of patients from a single hospital-based obstetrics and gynecology clinic who were tested for Trichomonas vaginalis between January 1, 2015 and December 31, 2019. Descriptive statistics were used to examine guideline-concordant testing for reinfection among patients with trichomoniasis. Multivariable logistic regression was used to identify characteristics associated with testing positive and with appropriate retesting. Subgroup analyses were performed for patients who were pregnant and tested positive for Trichomonas vaginalis.

RESULTS

Among the 8809 patients tested for Trichomonas vaginalis, 799 (9.1%) tested positive at least once during the study. Factors associated with trichomoniasis included identifying as non-Hispanic Black (adjusted odds ratio, 3.13; 95% confidence interval, 2.52-3.89), current or former tobacco smoking (adjusted odds ratio, 2.27; 95% confidence interval, 1.94-2.65), and single marital status (adjusted odds ratio, 1.96; 95% confidence interval, 1.51-2.56). Similar associated factors were found in the pregnant subgroup analysis. For women with trichomoniasis, guideline-concordant retesting rates were low across the entire population, with only 27% (214/799) of patients retested within the recommended time frame; 42% (82/194) of the pregnant subgroup underwent guideline-concordant retesting. Non-Hispanic Black women had significantly lower odds of undergoing guideline-recommended retesting than non-Hispanic White women (adjusted odds ratio, 0.54; 95% confidence interval, 0.31-0.92). Among patients tested according to guideline recommendations, we found a high rate of Trichomonas vaginalis positivity at retesting: 24% in the entire cohort (51/214) and 33% in the pregnant subgroup (27/82).

CONCLUSION

Trichomonas vaginalis infection was identified at a high frequency in a diverse, urban hospital-based obstetrics and gynecology clinic population. Opportunities exist to improve on equitable and guideline-concordant retesting of patients with trichomoniasis.

Prevalence of sexually transmissible infections in adolescents treated in a family planning outpatient clinic for adolescents in the western Amazon

Sexually transmitted infections (STIs) are among the most common public health problems worldwide, especially among adolescents and young adults, who account for almost 50% of all STI patients. Studies on the subject in the western Amazon are limited. This study aimed to evaluate the prevalence of STIs (chlamydia, gonorrhea, trichomoniasis, herpes simplex virus, syphilis, human immunodeficiency virus [HIV], hepatitis B, and hepatitis C) in adolescents treated at a family planning outpatient clinic in the western Amazon: Porto Velho, Rondônia, Brazil. A total of 196 adolescents were enrolled. During the gynecological examination, endocervical samples were collected to test for four STIs (chlamydia, gonorrhea, trichomoniasis, and herpes simplex virus), and blood samples were collected for the detection of HIV, syphilis, and hepatitis B and C. The mean age was 17.3 ± 1.5 years, the age at sexarche was 14.4 ± 1.6 years, and 54.6% of participants had their first sexual intercourse at 14 years or younger. Only 1.0% of the adolescents used condoms in all sexual relations, and 19.9% had casual partner(s) in the last year. In the evaluation of prevalence, we found that 32% of the adolescents had at least one STI, with the most prevalent being chlamydia (23%), followed by trichomoniasis (5.6%), herpes simplex (4.6%), and gonorrhea (3.1%). No positive cases of hepatitis B, hepatitis C, or HIV were detected, but 1% of the adolescents tested positive for syphilis. These indicators will support more effective health care strategies aimed at improving the quality of life of populations in this region of the western Amazon. In conclusion, our findings demonstrated high rates of STIs in the studied patients, reinforcing the need to expand epidemiological studies to implement more appropriate public policies and intervention strategies to prevent STIs in adolescents and other vulnerable populations in the western Amazon.

Identification of Trichomonas vaginalis 5-Nitroimidazole Resistance Targets

Trichomonas vaginalis is the most common non-viral sexually transmitted infection. 5-nitroimidazoles are the only FDA-approved medications for T. vaginalis treatment. However, 5-nitroimidazole resistance has been increasingly recognized and may occur in up to 10% of infections. We aimed to delineate mechanisms of T. vaginalis resistance using transcriptome profiling of metronidazole (MTZ)-resistant and sensitive T. vaginalis clinical isolates. In vitro, 5-nitroimidazole susceptibility testing was performed to determine minimum lethal concentrations (MLCs) for T. vaginalis isolates obtained from women who had failed treatment (n = 4) or were successfully cured (n = 4). RNA sequencing, bioinformatics, and biostatistical analyses were performed to identify differentially expressed genes (DEGs) in the MTZ-resistant vs. sensitive T. vaginalis isolates. RNA sequencing identified 304 DEGs, 134 upregulated genes and 170 downregulated genes in the resistant isolates. Future studies with more T. vaginalis isolates with a broad range of MLCs are needed to determine which genes may represent the best alternative targets in drug-resistant strains.

Infinity war: Trichomonas vaginalis and interactions with host immune response

Trichomonas vaginalis is the pathological agent of human trichomoniasis. The incidence is 156 million cases worldwide. Due to the increasing resistance of isolates to approved drugs and clinical complications that include increased risk in the acquisition and transmission of HIV, cervical and prostate cancer, and adverse outcomes during pregnancy, increasing our understanding of the pathogen's interaction with the host immune response is essential. Production of cytokines and cells of innate immunity: Neutrophils and macrophages are the main cells involved in the fight against the parasite, while IL-8, IL-6 and TNF-α are the most produced cytokines in response to this infection. Clinical complications: T. vaginalis increases the acquisition of HIV, stimulates the invasiveness and growth of prostate cells, and generates an inflammatory environment that may lead to preterm birth. Endosymbiosis: Mycoplasma hominis increased cytotoxicity, growth, and survival rate of the parasite. Purinergic signaling: NTPD-ases and ecto-5'-nucleotidase helps in parasite survival by modulating the nucleotides levels in the microenvironment. Antibodies: IgG was detected in serum samples of rodents infected with isolates from symptomatic patients as well as patients with symptoms. However, antibody production does not protect against a reinfection. Vaccine candidate targets: The transient receptor potential- like channel of T. vaginalis (TvTRPV), cysteine peptidase, and α-actinin are currently cited as candidate targets for vaccine development. In this context, the understanding of mechanisms involved in the host-T. vaginalis interaction that elicit the immune response may contribute to the development of new targets to combat trichomoniasis.

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.

Direct Measurement of Nucleoside Ribohydrolase Enzyme Activities in Trichomonas vaginalis Cells Using 19F and 13C-Edited 1H NMR Spectroscopy

Trichomoniasis is the most common nonviral sexually transmitted infection, affecting an estimated 275 million people worldwide. The causative agent is the parasitic protozoan Trichomonas vaginalis. Although the disease itself is typically mild, individuals with trichomonal infections have a higher susceptibility to more serious conditions. The emergence of parasite strains resistant to current therapies necessitates the need for novel treatment strategies. Since T. vaginalis is an obligate parasite that requires nucleoside salvage pathways, essential nucleoside ribohydrolase enzymes are promising new drug targets. Fragment screening and X-ray crystallography have enabled structure-guided design of inhibitors for two of these enyzmes. Linkage of enzymatic and antiprotozoal activity would be a transformative step toward designing novel, mechanism-based therapeutic agents. While a correlation with inhibition of purified enzyme would be mechanistically suggestive, a correlation with inhibition of in-cell enzyme activity would definitively establish this linkage. To demonstrate this linkage, we have translated our NMR-based activity assays that measure the activity of purified enzymes for use in T. vaginalis cells. The 19F NMR-based activity assay for the pyrimidine-specific enzyme translated directly to in-cell assays. However, the 1H NMR-based activity assay for the purine-specific enzyme required a switch from adenosine to guanosine substrate and the use of 13C-editing to resolve the substrate 1H signals from cell and growth media background signals. The in-cell NMR assays are robust and have been demonstrated to provide inhibition data on test compounds. The results described here represent the first direct measurement of enzyme activity in protozoan parasite cells.

Mass Spectrometry-Based Metabolomics Revealed Effects of Metronidazole on Giardia duodenalis

Giardia duodenalis is a significant protozoan that affects humans and animals. An estimated 280 million G. duodenalis diarrheal cases are recorded annually. Pharmacological therapy is crucial for controlling giardiasis. Metronidazole is the first-line therapy for treating giardiasis. Several metronidazole targets have been proposed. However, the downstream signaling pathways of these targets with respect to their antigiardial action are unclear. In addition, several giardiasis cases have demonstrated treatment failures and drug resistance. Therefore, the development of novel drugs is an urgent need. In this study, we performed a mass spectrometry-based metabolomics study to understand the systemic effects of metronidazole in G. duodenalis. A thorough analysis of metronidazole processes helps identify potential molecular pathways essential for parasite survival. The results demonstrated 350 altered metabolites after exposure to metronidazole. Squamosinin A and N-(2-hydroxyethyl)hexacosanamide were the most up-regulated and down-regulated metabolites, respectively. Proteasome and glycerophospholipid metabolisms demonstrated significant differential pathways. Comparing glycerophospholipid metabolisms of G. duodenalis and humans, the parasite glycerophosphodiester phosphodiesterase was distinct from humans. This protein is considered a potential drug target for treating giardiasis. This study improved our understanding of the effects of metronidazole and identified new potential therapeutic targets for future drug development.

Synthesis and in vitro antiprotozoal evaluation of novel metronidazole-Schiff base hybrids

Herein we report the synthesis of 21 novel small molecules inspired by metronidazole and Schiff base compounds. The compounds were evaluated against Trichomonas vaginalis and cross-screened against other pathogenic protozoans of clinical relevance. Most of these compounds were potent against T. vaginalis, exhibiting IC₅₀ values < 5 µM. Compound 20, the most active compound against T. vaginalis, exhibited an IC₅₀ value of 3.4 µM. A few compounds also exhibited activity against Plasmodium falciparum and Trypanosomal brucei brucei, with compound 6 exhibiting an IC₅₀ value of 0.7 µM against P. falciparum and compound 22 exhibiting an IC₅₀ value of 1.4 µM against T.b. brucei. Compound 22 is a broad-spectrum antiprotozoal agent, showing activities against all three pathogenic protozoans under investigation.

Biogenesis of extracellular vesicles in protozoan parasites: The ESCRT complex in the trafficking fast lane?

Extracellular vesicles (EVs) provide a central mechanism of cell-cell communication. While EVs are found in most organisms, their pathogenesis-promoting roles in parasites are of particular interest given the potential for medical insight and consequential therapeutic intervention. Yet, a key feature of EVs in human parasitic protozoa remains elusive: their mechanisms of biogenesis. Here, we survey the current knowledge on the biogenesis pathways of EVs secreted by the four main clades of human parasitic protozoa: apicomplexans, trypanosomatids, flagellates, and amoebae. In particular, we shine a light on findings pertaining to the Endosomal Sorting Complex Required for Transport (ESCRT) machinery, as in mammals it plays important roles in EV biogenesis. This review highlights the diversity in EV biogenesis in protozoa, as well as the related involvement of the ESCRT system in these unique organisms.

A deep learning approach reveals unexplored landscape of viral expression in cancer

About 15% of human cancer cases are attributed to viral infections. To date, virus expression in tumor tissues has been mostly studied by aligning tumor RNA sequencing reads to databases of known viruses. To allow identification of divergent viruses and rapid characterization of the tumor virome, we develop viRNAtrap, an alignment-free pipeline to identify viral reads and assemble viral contigs. We utilize viRNAtrap, which is based on a deep learning model trained to discriminate viral RNAseq reads, to explore viral expression in cancers and apply it to 14 cancer types from The Cancer Genome Atlas (TCGA). Using viRNAtrap, we uncover expression of unexpected and divergent viruses that have not previously been implicated in cancer and disclose human endogenous viruses whose expression is associated with poor overall survival. The viRNAtrap pipeline provides a way forward to study viral infections associated with different clinical conditions.

Diagnosis and treatment of infectious vaginitis: Proposal for a new algorithm

Background

Vaginitis is the most common gynecologic diagnosis in primary care, and most women have at least one episode during their lives. The need for standardized strategies to diagnose and treat vaginitis, both in primary care and among gynecologists, is emphasized. The Brazilian Group for Vaginal Infections (GBIV, acronym in Portuguese) aimed to update the practical approach to affected women by reviewing and discussing recent literature, and developing algorithms for diagnosis and treatment of vaginitis.

Methods

A literature search within biomedical databases PubMed and SCieLo was conducted in January 2022. The available literature was evaluated by three experienced researchers, members of the GBIV, to summarize the main data and develop practical algorithms.

Results and conclusion

Detailed algorithms were developed with the main goal to improve gynecological practice considering different scenarios and access to diagnostic tools, from the simplest to the most complex tests. Different age groups and specific contexts were also considered. The combination of anamnesis, gynecological examination, and complementary tests remains the basis of a proper diagnostic and therapeutic approach. Periodic updates of these algorithms are warranted as new evidence becomes available.

Drug susceptibility testing for oxygen-dependent and oxygen-independent resistance phenotypes in trichomonads

Trichomonas vaginalis is the most prevalent, non-viral sexually transmitted human infection, causing 170 million cases of trichomoniasis annually. Since the 1950s, treatment has relied on 5-nitroimidazoles (5NIs), leading to increasing drug resistance. A similar drug resistance problem is present in the veterinary pathogen, Tritrichomonas foetus. There are currently no agreed standards for defining 5NI resistance, due in part to two distinct oxygen-dependent ("aerobic") and oxygen-independent ("anaerobic") resistance phenotypes. Diagnostic tools to detect 5NI resistance are lacking, and current assays used to phenotypically assess 5NI resistance in vitro are complicated by these two resistance phenotypes. We demonstrate that microaerophilic conditions support sufficient parasite growth to interrogate oxygen-dependent resistance of 5NIs against known resistant and susceptible isolates of T. vaginalis and T. foetus. We further demonstrate that microaerophilic conditions allow sufficient growth for compatibility with existing growth assays, including our TriTOX assay. Adopting microaerophilic conditions eliminates traditional 'by-eye' estimates of minimum inhibitory concentrations and opens up options for increased throughput and automation, scalable to higher-throughput analyses of 5NI resistance. This would further allow the development of quantitative phenotypic standards to benchmark oxygen-dependent or oxygen-independent trichomonad 5NI resistance towards standardised surveillance programs to combat drug resistance.

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 and Genotype of Trichomonas vaginalis among Men in Xinxiang City, Henan Province, China

Trichomonas vaginalis (T. vaginalis) could cause trichomoniasis through sexual transmission, which was globally distributed. In this study, the prevalence and phylogenetic analyses of T. vaginalis among men in Xinxiang were conducted. From October 2018 to December 2019, a total of 634 male clinical samples were collected, including 254 samples of semen, 43 samples of prostate fluid, and 337 samples of urine. These samples were examined by nested PCR and a total of 32 (5.05%) T. vaginalis-positive samples were detected. Among these samples, the positive rates of T. vaginalis in semen, prostate fluid, and urine were 7.87% (20/254), 4.65% (2/43), and 2.97% (10/337), respectively. Three actin genes were successfully isolated and sequenced from the 32 positive DNA samples, and the analysis of the sequence and phylogenetic tree showed that the three actin gene sequences exhibited 99.7%-100% homology to the published actin gene sequence (EU076580) in NCBI, and the T. vaginalis strains in the three positive samples were identified as genotype E. Our results demonstrate a notable genotype of T. vaginalis in the male population and provide insight into the performance of these genetic markers in the molecular epidemiology of trichomoniasis. However, further studies are needed to research the association between the genotype and the pathogenicity of T. vaginalis.

The L-Rhamnose Biosynthetic Pathway in Trichomonas vaginalis: Identification and Characterization of UDP-D-Glucose 4,6-dehydratase

Trichomonas vaginalis is the causative agent of one of the most widespread sexually transmitted diseases in the world. The adhesion of the parasite to the vaginal epithelial cells is mediated by specific proteins and by a complex glycan structure, the lipoglycan (TvLG), which covers the pathogen surface. L-rhamnose is an important component of TvLG, comprising up to 40% of the monosaccharides. Thus, the inhibition of its production could lead to a severe alteration in the TvLG structure, making the L-rhamnose biosynthetic pathway an attractive pharmacologic target. We report the identification and characterization of the first committed and limiting step of the L-rhamnose biosynthetic pathway, UDP-D-glucose 4,6-dehydratase (UGD, EC 4.2.1.76). The enzyme shows a strong preference for UDP-D-glucose compared to dTDP-D-glucose; we propose that the mechanism underlying the higher affinity for the UDP-bound substrate is mediated by the differential recognition of ribose versus the deoxyribose of the nucleotide moiety. The identification of the enzymes responsible for the following steps of the L-rhamnose pathway (epimerization and reduction) was more elusive. However, sequence analyses suggest that in T. vaginalis L-rhamnose synthesis proceeds through a mechanism different from the typical eukaryotic pathways, displaying intermediate features between the eukaryotic and prokaryotic pathways and involving separate enzymes for the epimerase and reductase activities, as observed in bacteria. Altogether, these results form the basis for a better understanding of the formation of the complex glycan structures on TvLG and the possible use of L-rhamnose biosynthetic enzymes for the development of selective inhibitors.

Identification of the Constituents in Cnidii Fructus Active Against Trichomonas vaginalis Parasites

Ethanol extracts of Cnidii Fructus, the dried fruits of Cnidium monnieri (L.) Cusson, have been externally applied in the treatment of Trichomonas vaginalis. However, the precise identity of the major constituents responsible for activity against T. vaginalis is unknown, but there is probability they are coumarin derivatives. In this study, the anti-Trichomonas activity of 4 major coumarin derivative constituents of Cnidii Fructus, namely, osthole, xanthotoxin, isopimpinellin, and bergapten, was characterized in terms of the resulting kinetics of growth and morphology of T. vaginalis upon treatment. The results demonstrated that osthole and xanthotoxol had significant trichomonacidal ability, while isopimpinellin and bergapten displayed low or no inhibitory efficacy toward T. vaginalis parasites. Our study suggests that the coumarin derivatives osthole and xanthotoxol can be potentially used as a basis for the development and design of new drugs for application in alternative or synergistic therapy against T. vaginalis.

Cost-Effectiveness and Cost-Benefit Analyses of Providing Menstrual Cups and Sanitary Pads to Schoolgirls in Rural Kenya

Objective

To analyze the relative value of providing menstrual cups and sanitary pads to primary schoolgirls.

Design

Cost-effectiveness and cost-benefit analyses of three-arm single-site open cluster randomized controlled pilot study providing menstrual cups or sanitary pads for 1 year.

Participants

Girls 14-16 years of age enrolled across 30 primary schools in rural western Kenya.

Methods

Cost-effectiveness analysis was conducted based on the health effects (reductions in disability-adjusted life years [DALYs]) and education effects (reductions in school absenteeism) of both interventions. The health and education benefits were separately valued and compared with relative program costs.

Results

Compared with the control group, the cost of menstrual cups was estimated at $3,270 per year for 1000 girls, compared with $24,000 for sanitary pads. The benefit of the menstrual cup program (1.4 DALYs averted, 95% confidence interval [CI]: -4.3 to 3.1) was higher compared with a sanitary pad program (0.48 DALYs averted, 95% CI: -4.2 to 2.3), but the health effects of both interventions were not statistically significant likely due to the limited statistical power. Using point estimates, the menstrual cup intervention was cost-effective in improving health outcomes ($2,300/DALY averted). The sanitary pad intervention had a cost-effectiveness of $300/student-school year in reducing school absenteeism. When considering improvements in future earnings from reduced absenteeism, the sanitary pad program had a net benefit of +$68,000 (95% CI: -$32,000 to +$169,000).

Conclusions

The menstrual cup may provide a cost-effective solution for menstrual hygiene management in low-income settings. This study outlines a methodology for future analyses of menstrual hygiene interventions and highlights several knowledge gaps that need to be addressed. Trial registration: ISRCTN17486946.

Structure-Guided Insight into the Specificity and Mechanism of a Parasitic Nucleoside Hydrolase

Trichomonas vaginalis is the causative parasitic protozoan of the disease trichomoniasis, the most prevalent, nonviral sexually transmitted disease in the world. T. vaginalis is a parasite that scavenges nucleosides from the host organism via catalysis by nucleoside hydrolase (NH) enzymes to yield purine and pyrimidine bases. One of the four NH enzymes identified within the genome of T. vaginalis displays unique specificity toward purine nucleosides, adenosine and guanosine, but not inosine, and atypically shares greater sequence similarity to the pyrimidine hydrolases. Bioinformatic analysis of this enzyme, adenosine/guanosine-preferring nucleoside ribohydrolase (AGNH), was incapable of identifying the residues responsible for this uncommon specificity, highlighting the need for structural information. Here, we report the X-ray crystal structures of holo, unliganded AGNH and three additional structures of the enzyme bound to fragment and small-molecule inhibitors. Taken together, these structures facilitated the identification of residue Asp231, which engages in substrate interactions in the absence of those residues that typically support the canonical purine-specific tryptophan-stacking specificity motif. An altered substrate-binding pose is mirrored by repositioning within the protein scaffold of the His80 general acid/base catalyst. The newly defined structure-determined sequence markers allowed the assignment of additional NH orthologs, which are proposed to exhibit the same specificity for adenosine and guanosine alone and further delineate specificity classes for these enzymes.

Induction of apoptosis by hydroalcoholic and methanolic extract of Deracocephalum kotschyi on Trichomonas vaginalis

Trichomonas vaginalis (T.vaginalis) causes trichomoniasis, a sexually transmitted infection. Dracocephalum kotschyi (D. kotschyi) belongs to the family of Labiatae. Its antispasmodic and analgesic properties are well known in Iran. This work aimed to look into the antitrichomonal activity of D. kotschyi extracts against T. vaginalis in vitro. D. kotschyi was gathered in Isfahan Province, Iran, and extracts were prepared and isolated. Later, T. vaginalis trophozoites obtained from Iran, which are metronidazole-sensitive, were incubated with various doses of extracts. Cell viability was used to determine the half-maximal inhibitory concentration (IC50) and percentage of growth inhibition (GI%). Cytotoxicity of the extracts was determined by MTT assay on the J774.A1 cell line. The effect of extracts during the initial stage of apoptosis was assayed using the fluorescein isothiocyanate (FITC) Annexin V Apoptosis Detection Kit I (BD Pharmingen™). Compared to MTZ, extracts generated more efficient lysis on T. vaginalis trophozoites. Evaluation of the in vitro anti trichomonal properties of D. kotschyi essential extracts shows that it effectively induces apoptosis on T. vaginalis between 100 and 500 µg/ml after 48 h without toxicity on hematopoietic cells. According to this study, D. kotschyi extracts induce programmed death in T. vaginalis. The extracts of D. kotschyi can be used to develop antitrichomonal drugs.

In Vitro Effect of 5-Nitroimidazole Drugs against Trichomonas vaginalis Clinical Isolates

Infections with the sexually transmitted parasite Trichomonas vaginalis are normally treated with metronidazole, but cure rates are suboptimal and recurrence rates following treatment are high. Therefore, our objective was to assess the in vitro antitrichomonas activities of three other 5-nitroimidazole drugs and compare them with metronidazole. T. vaginalis isolates (n = 94) isolated from South African women presenting with vaginal discharge syndrome at two sexually transmitted disease clinics in KwaZulu-Natal were grown from frozen stock. Twofold serial dilutions (16 to 0.25 mg/L) of metronidazole, tinidazole, ornidazole, and secnidazole were prepared in Diamond's broth. The MICs were read after 48 h of anaerobic incubation at 37°C. An MIC of <2 mg/L was defined as susceptible, an MIC of 2 mg/L was defined as intermediate, and an MIC of >2 mg/L was defined as resistant. Sixty-one percent (57/94) of the T. vaginalis isolates were susceptible to metronidazole, 80% (75/94) were susceptible to tinidazole, 75% (71/94) were susceptible to secnidazole, and 89% (84/94) were susceptible to ornidazole. Resistance levels were 11%, 2%, and 1% for metronidazole, tinidazole, and secnidazole, respectively, while no resistance was observed for ornidazole. Intermediate scores were 28% for metronidazole, 18% for tinidazole, 24% for secnidazole, and 11% for ornidazole. Isolates from a proportion of women with bacterial vaginosis (BV) had higher MICs, and no isolates from women coinfected with another sexually transmitted infectious organism were resistant to any of the antimicrobials tested. This study showed that among T. vaginalis isolates in KwaZulu-Natal, there is no in vitro resistance to ornidazole. Of the 5-nitroimidazoles, metronidazole showed the highest level of resistance. The very low levels of resistance for the other three antimicrobials indicate that all three are viable options as a replacement for metronidazole if these in vitro findings are found to correlate with clinical outcomes. IMPORTANCE Trichomonas vaginalis is the most common nonviral sexually transmitted infection associated with reproductive sequelae and HIV acquisition risk worldwide. Despite its role in reproductive health, a high prevalence in South Africa, and the reported metronidazole resistance worldwide, no alternative regimens have been tested against T. vaginalis in our setting. This study compared the susceptibility patterns of three other 5-nitroiminazoles (secnidazole, tinidazole, and ornidazole), which are active against T. vaginalis with metronidazole in vitro. Metronidazole, the drug of choice for the treatment of trichomoniasis, showed the highest level of resistance, while the three regimens showed very low levels of resistance. These data indicate that all three are viable options as a replacement for metronidazole if these in vitro findings are found to correlate with clinical outcomes.

Sexually transmitted pathogens causing urethritis: A mini-review and proposal of a clinically based diagnostic and therapeutic algorithm

The purpose of this mini-review was to provide the latest information and concepts on diagnosis and treatment of the most common sexually transmitted pathogens causing urethritis. The incidence of several sexually transmitted infections that cause urethritis is increasing, and this genitourinary syndrome is among the most common reason young men see clinical care. The authors performed a literature search including the currently valid guidelines, and an overview of the most relevant pathogens is given. Moreover, the authors developed a clinically applicable diagnostic and therapeutic algorithm, because early diagnosis and correct treatment can sometimes prevent infected individuals from significant morbidity. Future research will focus on new methods to combat pathogens that cause urethritis, including vaccination.

Consistency analysis of the Sysmex UF-5000 and Atellica UAS 800 urine sedimentation analyzers

OBJECTIVE

To evaluate the consistency between the results of Sysmex UF-5000 system and Atellica® UAS 800 Urine Sediment Analyzer.

METHODS

A total of 636 random urine samples were collected from inpatients and outpatients from March to September 2021. Urine was collected for analysis by the Sysmex UF-5000, Atellica UAS 800 systems, and manual microscopic examination. The results of manual microscopy as the gold standard, the coincidence rate and false-negative rate of Sysmex UF-5000 and Atellica UAS 800 systems in the detection of red blood cells, white blood cells, and casts were calculated.

RESULTS

The coincidence rates of red blood cells, white blood cells, and cast, crystals, and other sediment components for the Sysmex UF-5000 system were 85.37%, 87.89%, 91.67%, 88.36%, and 71.86%. The false-negative rates were 28.47%, 3.75%, 68.97%, 37.25%, and 30.63%. The coincidence rates of red blood cells, white blood cells, and cast, crystals, and other sediment components for the Atellica UAS 800 system were 85.06%, 90.25%, 59.12%, 91.67%, and 67.45% and the false-negative rates were 60.42%, 21.25%, 36.21%, 19.64%, and 35.80%.

CONCLUSION

Two instruments are superior in the detection of red blood cells and white blood cells. The Atellica UAS 800 system with image review has a good coincidence rate in the identification of crystals and casts. The identification of various sediment components in urine by both instruments meets the laboratory requirements. Two instruments with different methodologies have their own characteristics, and we should reasonably use them according to the conditions of the laboratory.

A Microbial Piñata: Bacterial Endosymbionts of Trichomonas vaginalis Come in Different Flavors

The protozoan parasite Trichomonas vaginalis causes trichomoniasis, a prevalent human urogenital infection with significant morbidity that is commonly associated with vaginal dysbiosis. Exacerbation of T. vaginalis pathogenicity has been related to endosymbionts, including mycoplasma, and thought for a while to be solely attributable to Mycoplasma hominis. In a recent publication, Margarita and colleagues (https://journals.asm.org/doi/10.1128/mbio.00918-22) showed that endosymbiosis extends to a second species of mycoplasma known as "Candidatus Mycoplasma girerdii." Those authors confirmed the strong association of T. vaginalis with both species of mycoplasma by reassessing clinical samples. Additionally, they showed that in vitro symbiosis of protozoa and bacteria resulted in the modulation of gene expression of T. vaginalis and enhancement of parasite cytoadhesion and hemolytic activity in culture assays. In this commentary, we portray T. vaginalis as a synergistically interacting multimicrobe organism-a "microbial piñata"-whose endosymbionts contribute significantly to the pathophysiology of this medically important protozoan parasite.

Secnidazole: a treatment for trichomoniasis in adolescents and adults

INTRODUCTION

Single-dose 2-g oral secnidazole (SEC), newly approved by the U.S. Food and Drug administration (FDA) for treatment of trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various micro-organisms. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other FDA-approved treatments for trichomoniasis in the United States - metronidazole and tinidazole - SEC has favorable pharmacokinetics, including a longer half-life and a lower minimal lethal concentration.

AREAS COVERED

This work summarizes the chemistry and pharmacology of SEC and reviews the evidence on its efficacy, tolerability, and safety for the treatment of trichomoniasis.

EXPERT OPINION

SEC is an efficacious, well tolerated, and safe treatment for patients aged ≥12 years with trichomoniasis. Single-dose administration makes it a favorable treatment option, especially in cases where adherence to multi-dose treatment regimens may be low.

Unexpected Presence of Blastocystis Subtype 1-3 DNA in Human Vaginal and Sperm Samples Coinfected with Trichomonas vaginalis

There have been few reports on extra-enteric infections by <i>Blastocystis</i> STs and none have been molecularly identified in samples from human reproductive organs. We report for the first time the identification of 3 different subtypes of <i>Blastocystis</i> (ST1-3) in vaginal and sperm samples, from patients infected with <i>Trichomonas vaginalis</i>. <i>Blastocystis</i> STs were identified by PCR-sequencing and by phylogenetic inferences using 28 vaginal swab samples and 7 sperm samples from patients trichomoniasis. <i>Blastocystis</i> STs were identified in 6 of 28 vaginal swabs (21.4%) and in 3 of 7 sperm samples (42.8%). In both biological samples, STs 1-3 were found; one vaginal sample showed subtype co-infection with ST1 and ST3. High genetic variation was observed in the sequences obtained and no specific clustering in the phylogenetic trees was detected. Most of the haplotypes identified were placed far from the main dispersal centers. Our finding suggested that incorrect cleaning of the genital area or a contamination by combination of anal and vaginal intercourse.

Omics Analyses of Trichomonas vaginalis Actin and Tubulin and Their Participation in Intercellular Interactions and Cytokinesis

Actin and tubulin proteins from Trichomonas vaginalis are crucial for morphogenesis and mitosis. This parasite has 10 and 11 genes coding bonafide actin and tubulin proteins, respectively. Hence, the goal of this work was to analyze these actin and tubulin genes, their expression at the mRNA and protein levels, and their parasite localization in intercellular interaction and cytokinesis. Representative bonafide actin (tvact1) and tubulin (tvtubα1) genes were cloned into and expressed in Escherichia coli. The recombinant proteins TvACT1r and TvTUBα1r were affinity purified and used as antigens to produce polyclonal antibodies. These antibodies were used in 1DE and 2DE WB and indirect immunofluorescence assays (IFA). By IFA, actin was detected as a ring on the periphery of ameboid, ovoid, and cold-induced cyst-like parasites, on pseudopods of amoeboid parasites, and in cytoplasmic extensions (filopodia) in cell–cell interactions. Tubulin was detected in the axostyle, flagellum, undulating membrane, and paradesmose during mitosis. Paradesmose was observed by IFA mainly during cytokinesis. By scanning electron microscopy, a tubulin-containing nanotubular structure similar to the tunneling nanotubes (TNTs) was also detected in the last stage of cytokinesis. In conclusion, actin and tubulin are multigene families differentially expressed that play important roles in intercellular interactions and cytokinesis.

Myrtle-Functionalized Nanofibers Modulate Vaginal Cell Population Behavior While Counteracting Microbial Proliferation

Vaginal infections affect millions of women annually worldwide. Therapeutic options are limited, moreover drug-resistance increases the need to find novel antimicrobials for health promotion. Recently phytochemicals were re-discovered for medical treatment. Myrtle (Myrtus communis L.) plant extracts showed in vitro antioxidant, antiseptic and anti-inflammatory properties thanks to their bioactive compounds. The aim of the present study was to create novel nanodevices to deliver three natural extracts from leaves, seeds and fruit of myrtle, in vaginal milieu. We explored their effect on human cells (HeLa, Human Foreskin Fibroblast-1 line, and stem cells isolated from skin), resident microflora (Lactobacillus acidophilus) and on several vaginal pathogens (Trichomonas vaginalis, Escherichia coli, Staphylococcus aureus, Candida albicans, Candida kefyr, Candida glabrata, Candida parapsilosis, Candida krusei). Polycaprolactone-Gelatin nanofibers encapsulated with leaves extract and soaked with seed extracts exhibited a different capability in regard to counteracting microbial proliferation. Moreover, these nanodevices do not affect human cells and resident microflora viability. Results reveal that some of the tested nanofibers are interesting candidates for future vaginal infection treatments.