Effect of Trichomonacide 6-Nitro-1H-benzimidazole Derivative Compounds on Expression Level of Metabolic Genes in Trichomonas vaginalis

The parasite Trichomonas vaginalis is the etiologic agent of trichomoniasis, the most common non-viral sexually transmitted disease worldwide. This infection often remains asymptomatic and is related to several health complications. The traditional treatment for trichomoniasis is the use of drugs of the 5-nitroimidazole family, such as metronidazole; however, scientific reports indicate an increasing number of drug-resistant strains. Benzimidazole derivatives could offer an alternative in the search for new anti-trichomonas drugs. In this sense, two attractive candidates are the compounds O2N-BZM7 and O2N-BZM9 (1H-benzimidazole derivatives), since, through in vitro tests, they have shown a higher trichomonacide activity. In this study, we determined the effect on the expression level of metabolic genes in T. vaginalis. The results show that genes involved in redox balance (NADHOX, G6PD::6PGL) are overexpressed, as well as the gene that participates in the first reaction of glycolysis (CK); on the other hand, structural genes such as ACT and TUB are decreased in expression in trophozoites treated with the compound O2N-BZM9, which would probably affect its morphology, motility and virulence. These results align with the trichomonacidal activity of the compounds, with benzimidazole O2N-BZM9 being the most potent, with an IC50 value of 4.8 μM. These results are promising for potential future therapeutic applications.

Single gene targeted nanopore sequencing enables simultaneous identification and antimicrobial resistance detection of sexually transmitted infections

Objectives

To develop a simple DNA sequencing test for simultaneous identification and antimicrobial resistance (AMR) detection of multiple sexually transmitted infections (STIs).

Methods

Real-time PCR (qPCR) was initially performed to identify Neisseria gonorrhoeae (NG), Chlamydia trachomatis (CT), Mycoplasma genitalium (MG) and Trichomonas vaginalis (TV) infections among a total of 200 vulvo-vaginal swab samples from female sex workers in Ecuador. qPCR positive samples plus qPCR negative controls for these STIs were subjected to single gene targeted PCR MinION-nanopore sequencing using the smartphone operated MinIT.

Results

Among 200 vulvo-vaginal swab samples 43 were qPCR positive for at least one of the STIs. Single gene targeted nanopore sequencing generally yielded higher pathogen specific read counts in qPCR positive samples than qPCR negative controls. Of the 26 CT, NG or MG infections identified by qPCR, 25 were clearly distinguishable from qPCR negative controls by read count. Discrimination of TV qPCR positives from qPCR negative controls was poorer as many had low pathogen loads (qPCR cycle threshold >35) which produced few specific reads. Real-time AMR profiling revealed that 3/3 NG samples identified had gyrA mutations associated with fluoroquinolone resistance, 2/10 of TV had mutations related to metronidazole resistance, while none of the MG samples possessed 23S rRNA gene mutations contributing to macrolide resistance.

Conclusions

Single gene targeted nanopore sequencing for diagnosing and simultaneously identifying key antimicrobial resistance markers for four common genital STIs shows promise. Further work to optimise accuracy, reduce costs and improve speed may allow sustainable approaches for managing STIs and emerging AMR in resource poor and laboratory limited settings.

Pharmacological activities of Asclepias curassavica L. (Apocynaceae) aerial parts

ETHNOPHARMACOLOGICAL RELEVANCE

Asclepias curassavica L. (Apocynaceae) is a perennial shrub used in the folk treatment of parasitism, pain, and inflammation.

AIM OF THE STUDY

This work assessed the antiparasitic, anti-inflammatory, antinociceptive, and sedative effects of an ethanol extract from the aerial parts of Asclepias curassavica (ACE).

MATERIALS AND METHODS

The antiparasitic activity against Trichomonas vaginalis was evaluated using the trypan blue exclusion test. The in vitro anti-inflammatory actions of ACE (1-200 μg/ml) were analyzed using LPS-stimulated primary murine macrophages. The in vivo pharmacological activity of ACE (50-200 mg/kg p.o.) was evaluated using animal models of inflammation (TPA-induced ear edema test and carrageenan-induced paw edema test) and nociception (acetic acid-induced writhing test, formalin-induced licking test, and hot plate test).

RESULTS

ACE showed poor antiparasitic effects against Trichomonas vaginalis (IC₅₀ = 302 μg/ml). ACE increased the production of IL-10 in both in vitro assays (EC₅₀ = 3.2 pg/ml) and in vivo assays (ED₅₀ = 111 mg/kg). ACE showed good antinociceptive actions (ED₅₀ = 158 mg/kg in phase 1 and ED₅₀ = 83 mg/kg in phase 2) in the formalin test. Pre-treatment with naloxone blocked the antinociceptive response induced by ACE. In addition, ACE did not induce sedative effects or motor coordination deficits in mice.

CONCLUSION

Findings showed that the anti-inflammatory activity of ACE is associated with increasing levels of IL-10 in both in vitro and in vivo assays, whereas the antinociceptive effect is associated with the participation of the opioidergic system, without inducing sedation or motor coordination impairment.

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

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

Predictors of Urinary Tract Infections in Children and Antibiotic Susceptibility Pattern in the Buea Health District, South West Region, Cameroon

Urinary tract infections (UTI) are among the most common pediatric infections and if not promptly diagnosed and treated, it could cause long term complications. Worldwide and in Cameroon, little attention has been paid to this growing problem in the pediatric population. Identification of risk factors will contribute significantly to prevention. A cross-sectional case-control study was carried out in children ≤ 15 years to identify the risk factors of UTI, etiologic agents, and their antibiotic susceptibility. Samples (urine) were collected from in and outpatients with symptoms of UTI attending two health facilities in Buea. Controls were age- and sex-matched children in the community and those visiting these health facilities for unrelated reasons. Samples were analyzed by microscopy, culture, and antibiotic susceptibility of bacteria isolates tested by the disc diffusion technique. Questionnaires were administered to collect sociodemographic, clinical characteristics and data on risk factors. Odds ratios and bivariate and multivariate analyses were used to assess the relationship between predictors (symptoms and risk factors) and UTI. P < 0.05 was considered significant. A total of 405 participants (200 cases and 205 controls) were investigated. UTI prevalence was 12% in cases. From the UTI cases, bacteria was the major cause of infection, with E. coli (39.4%) predominating. Parasitic organisms, Trichomonas vaginalis (0.5%) and Schistosoma spp (0.5%), and yeast (6%) were also detected. Urinary urgency (F = 4.98, P = 0.027) and back pain (F = 12.37, P = 0.001) were associated to UTI following bivariate analysis. These parameters could be used to predict UTI in the pediatric population in the study area. Third generation cephalosporins: ceftriaxone (90.1%) and cefadroxil (85.4%) were the most effective and thus recommended for treatment.

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

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

Updates in trichomonas treatment including persistent infection and 5-nitroimidazole hypersensitivity

PURPOSE OF REVIEW

The purpose of this review is to update information on treatment of Trichomonas vaginalis. T. vaginalis is estimated to be the most common treatable sexually transmitted infection. In the world and is associated with poor birth outcomes, cervical cancer, sperm motility and morphology issues, and HIV acquisition and transmission.

RECENT FINDINGS

The efficacy of the recommended 2-g oral single-dose metronidazole (MTZ) for the treatment of T. vaginalis in women has recently been challenged. Two recent multicentered randomized trials and a meta-analysis have demonstrated that the 7-day dose of MTZ 500 mg twice daily was nearly two times more efficacious at clearing infection compared with the 2-g dose. Partner treatment is also essential, since up to 70% of male sexual partners can be infected and rescreening of treated women at 3 months is also recommended given the high repeat infection rates. Future studies should examine the importance of treating asymptomatic T. vaginalis, best treatment for men, the influence of the microbiome on treatment efficacy and different formulations of intravaginal treatments for hypersensitivity.

SUMMARY

7-day 500 mg twice daily MTZ should be used as the first line treatment for T. vaginalis-infected women.

2'-Hydroxychalcones as an alternative treatment for trichomoniasis in association with metronidazole

The treatment for trichomoniasis, based on 5'-nitroimidazol agents, has been presenting failures related to allergic reactions, side effects, and the emergence of resistant isolates. There are no alternative drugs approved for the treatment of these cases; thus, the search for new active molecules is necessary. In this scenario, chalcones have been extensively studied for their promising biological activities. Here, we presented the synthesis of three hydroxychalcones (3a, b, and c), in vitro and in silico analyses against Trichomonas vaginalis. The in vitro biological evaluation showed that hydroxychalcone 3c presented anti-T. vaginalis activity, with complete death in 12 h of incubation at minimum inhibitory concentration (MIC) of 100 μM. 3c showed a dose-dependent cytotoxicity against mammalian VERO cell line, but the association of 3c at 12.5 μM and metronidazole (MTZ) at 40 μM showed 95.31% activity against T. vaginalis trophozoites after 24 h of exposure and did not affect the VERO cell growth, appearing to be a good alternative. In silico analysis by molecular docking showed that 3c could inhibit the activity of TvMGL (methionine gamma-lyase), TvLDH (lactate dehydrogenase), and TvPNP (purine nucleoside phosphorylase) affecting the T. vaginalis survival and also suggesting a different mechanism of action from MTZ. Therefore, these results propose that hydroxychalcones are promising anti-T. vaginalis agents and must be considered for further investigations regarding trichomoniasis treatment.

Prevalence of double-stranded RNA virus in Trichomonas vaginalis isolated in Italy and association with the symbiont Mycoplasma hominis

The flagellated protozoon Trichomonas vaginalis, responsible for trichomoniasis, can establish a symbiotic relationship with the bacterium Mycoplasma hominis and can harbor double-stranded RNA Trichomonasvirus (TVV). In this study, we investigated by real-time PCR the prevalence of the four TVVs and of M. hominis among 48 T. vaginalis strains isolated in Italy, and we evaluated a possible association with metronidazole resistance. Fifty percent of the analyzed trichomonad strains tested positive for at least one TVV T. vaginalis, with TVV2 being the most prevalent, followed by TVV1 and TVV3. Two T. vaginalis strains were infected by TVV4, detected in Europe for the first time. Interestingly, we found more than one TVV species in 75% of positive trichomonad strains. M. hominis was present in 81.25% of T. vaginalis isolates tested, and no statistically significant association was observed with the infection by any TVV. Metronidazole sensitivity of T. vaginalis isolates was evaluated in vitro, and no correlation was observed between minimal lethal concentration and the presence of TVVs. This is the first report on TVV infection of T. vaginalis in Italy. Even if no association of TVV positive isolates with the presence of the symbiont M. hominis or with metronidazole resistance was observed, further studies are needed to shed light on the effective role of infecting microorganisms on the pathophysiology of T. vaginalis.

Design and Application of a High-Throughput, High-Content Screening System for Natural Product Inhibitors of the Human Parasite Trichomonas vaginalis

It is estimated that Trichomonas vaginalis affects an astonishing 3.9% of the world's population, and while many of those infected are asymptomatic, progression of the disease can lead to serious health problems. Currently, the nitroimidazoles constitute the only drug class approved to treat trichomoniasis in the United States, which makes the spread of drug resistance a realistic concern. We developed a new image-based, high-throughput, and high-content assay for testing natural products (purified compounds and extracts) for antitrichomonal activity. Applying this assay system to a library of fungal natural product extracts led to the identification of three general classes of natural product inhibitors that exhibited moderate to strong activities against T. vaginalis: anthraquinones, xanthone-anthraquinone heterodimers, and decalin-linked tetramic-acid-containing metabolites. The tetramate natural products emerged as the most promising candidate molecules with pyrrolocin A (51) exhibiting potent activity against the parasite (EC50 = 60 nM), yet this metabolite showed limited toxicity to mammalian cell lines (selectivity index values of 100 and 167 versus 3T3 fibroblast and Ect1 normal cervical cells, respectively). The imaging-based assay system is a powerful tool for the bioassay-guided purification of single-component antitrichomonal biomolecules from complex natural product mixtures.

Increased intracellular Cl- concentration mediates Trichomonas vaginalis-induced inflammation in the human vaginal epithelium

Trichomonas vaginalis is a primary urogenital parasite that causes trichomoniasis, a common sexually transmitted disease. As the first line of host defense, vaginal epithelial cells play critical roles in orchestrating vaginal innate immunity and modulate intracellular Cl^- homeostasis via the cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel that plays positive roles in regulating nuclear factor-κB (NF-κB) signalling. However, the association between T. vaginalis infection and intracellular Cl^- disequilibrium remains elusive. This study showed that after T. vaginalis infection, CFTR was markedly down-regulated by cysteine proteases in vaginal epithelial cells. The intracellular Cl^- concentration ([Cl^-]_i) was consequently elevated, leading to NF-κB signalling activation via serum- and glucocorticoid-inducible kinase-1. Moreover, heightened [Cl^-]_i and activated NF-κB signalling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP through NF-κB-mediated up-regulation of phosphodiesterase 4. The results conclusively revealed that the intracellular Cl^- of the human vaginal epithelium could be dynamically modulated by T. vaginalis, which contributed to mediation of epithelial inflammation in the human vagina.

Epinecidin-1: A marine fish antimicrobial peptide with therapeutic potential against Trichomonas vaginalis infection in mice

Trichomoniasis is caused by infection with the protozoan parasite Trichomonas vaginalis, and prolonged persistence may lead to serious ill effects in patients. Thus, the development of new therapeutic strategies to combat drug-resistant T. vaginalis would be clinically beneficial. Antimicrobial peptides (AMPs) comprise an emerging class of molecules that may serve as effective alternatives to antibiotics. In this report, we demonstrate that the synthetic fish AMP, Epinecidin-1 (Epi-1), acts against T. vaginalis both in vitro and in vivo. Under in vitro conditions, Epi-1 disrupted the membrane of metronidazole-resistant T. vaginalis and completely killed the pathogen. To mimic human infection in vivo, estradiol-stimulated mice with vaginal Lactobacillus acidophilus colonization were infected with T. vaginalis, followed by treatment with Epi-1, Vigill, metronidazole or furazolidone. After seven days, the T. vaginalis content was effectively decreased in Epi-1 treated mice, as measured by acridine orange staining of wet smears and tissue biopsies, as well as qPCR of vaginal discharge DNA. Taken together, our results demonstrate that Epi-1 is a strong candidate for development as an alternative therapeutic for T. vaginalis infection.

Anti-Trichomonas vaginalis activity of chalcone and amino-analogues

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

Cinnamoyl-Oxaborole Amides: Synthesis and Their in Vitro Biological Activity

Due to the increased interest in their application in the treatment of infectious diseases, boron-containing compounds have received a significant coverage in the literature. Herein, a small set of novel cinnamoly-oxaborole amides were synthesized and screened against nagana Trypanosoma brucei brucei for antitrypanosomal activity. Compound 5g emerged as a new hit with an in vitro IC50 value of 0.086 μM against T. b. brucei without obvious inhibitory activity against HeLa cell lines. The same series was also screened against other human pathogens, including Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), for which moderate to weak activity (10 to >125 μM) was observed. Similarly, these compounds exhibited moderate activity against the human protozoal pathogen Trichomonas vaginalis with no observed effect on common microbiome bacterial species. The cross-species inhibitory activity presents the possibility of these compounds serving as broad-spectrum antibiotics for these prevalent three human pathogens.

Comparative effect of manuka honey on anaerobic parasitic protozoans with standard drug therapy under in vitro conditions: A preliminary study

BACKGROUND

From the past five decades, metronidazole and tinidazole have been used for treating nonresistant and resistant giardiasis and trichomoniasis. However, due to the occurrence of drug resistance to standard therapy idealizes us to explore some additional therapies which is cost-effective, easy accessibility, and natural which has least side effects. Manuka honey obtained from Leptospermum scoparium is well known for its antibacterial and wound healing properties and is thought to be a better option as an additional therapy.

OBJECTIVE

The present study was conducted to find out the effect of manuka honey on anaerobic protozoans that includes Giardia and Trichomonas under in vitro conditions in comparison to metronidazole and tinidazole.

MATERIALS AND METHODS

Axenic culture of Giardia lamblia strain Portland 1 and Trichomonas vaginalis strain 413 was used for drug sensitivity assay to tinidazole, metronidazole, and manuka honey with the highest concentration of 17.1 μg/ml, 24.7 μg/ml, and 50%v/v by using (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole). For this, head-to-head comparison has been done and IC 50 of the standard drug as well as manuka honey was calculated.

RESULTS

The result showed that percentage inhibition on the growth of both the parasites is dependent on concentration as well as exposure time of the drug. The calculated IC 50 was found to be 5.6%v/v and 1.5%v/v for manuka honey with respect to G. lamblia and T. vaginalis.

CONCLUSION

The present study suggests that manuka honey can be used as an additional therapy for the patient with giardiasis or trichomoniasis. However, in vivo study in the near future will elucidate more about the effectiveness of honey in treating parasitic infections.

Redox Pathways as Drug Targets in Microaerophilic Parasites

The microaerophilic parasites Entamoeba histolytica, Trichomonas vaginalis, and Giardia lamblia jointly cause hundreds of millions of infections in humans every year. Other microaerophilic parasites such as Tritrichomonas foetus and Spironucleus spp. pose a relevant health problem in veterinary medicine. Unfortunately, vaccines against these pathogens are unavailable, but their microaerophilic lifestyle opens opportunities for specifically developed chemotherapeutics. In particular, their high sensitivity towards oxygen can be exploited by targeting redox enzymes. This review focusses on the redox pathways of microaerophilic parasites and on drugs, either already in use or currently in the state of development, which target these pathways.

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

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

Mycoplasma hominis impacts gene expression in Trichomonas vaginalis

In Europe, up to 90% of isolated Trichomonas vaginalis strains are naturally infected with Mycoplasma hominis, a facultative pathogen of the human genital tract. The consequences of this endosymbiosis are not yet well understood. The aim of the current study was to evaluate the impact of natural and artificial infections with M. hominis on the RNA expression levels of metronidazole susceptibility-associated genes of T. vaginalis. Three T. vaginalis strains (TVSS10-, TVSS25-, G3) without M. hominis, as well as the same strains naturally (TVSS10+, TVSS25+) and artificially (G3-MhSS25, TVSS25-MhSS25) infected with M. hominis, were investigated for their expression profiles of three genes associated with metronidazole resistance (ferredoxin, flavin reductase 1 and pyruvate:ferredoxin oxidoreductase). The minimal inhibitory concentrations (MICs) of metronidazole were evaluated for all combinations and the respective M. hominis-free T. vaginalis strains were used as controls. The sole presence of M. hominis led to a down-regulation of metronidazole susceptibility-associated genes in all T. vaginalis strains tested. Interestingly, the effect was more prominent in the artificial symbioses. Moreover, a twofold enhancement of metronidazole tolerability was observed in three infected T. vaginalis strains, compared to the respective strains without M. hominis. In conclusion, M. hominis had an impact on gene expression in all T. vaginalis strains and on metronidazole MIC in all but one strain tested.

Chemical composition, immunostimulatory, cytotoxic and antiparasitic activities of the essential oil from Brazilian red propolis

Most studies of Brazilian red propolis have explored the composition and biological properties of its ethanolic extracts. In this work, we chemically extracted and characterized the essential oil of Brazilian red propolis (EOP) and assessed its adjuvant, antiparasitic and cytotoxic activities. The chemical composition of EOP was analyzed using gas chromatography with mass spectrometry (GC-MS). EOP was tested for in vitro activity against Trichomonas vaginalis (ATCC 30236 isolate); trophozoites were treated with different concentrations of EOP (ranging from 25 to 500 μg/mL) in order to establish the MIC and IC₅₀ values. A cytotoxicity assay was performed in CHO-K1 cells submitted to different EOP concentrations. BALB/c mice were used to test the adjuvant effect of EOP. The animals were divided in 3 groups and inoculated as follows: 0.4 ng/kg BW EOP (G1); 50 μg of rCP40 protein (G2); or a combination of 0.4 ng/kg BW EOP and 50 μg of rCP40 (G3). Total IgG, IgG1 and IgG2a levels were assessed by ELISA. The major constituent compounds of EOP were methyl eugenol (13.1%), (E)-β-farnesene (2.50%), and δ-amorphene (2.3%). Exposure to EOP inhibited the growth of T. vaginalis, with an IC₅₀ value of 100 μg/mL of EOP. An EOP concentration of 500 μg/mL was able to kill 100% of the T. vaginalis trophozoites. The EOP kinetic growth curve showed a 36% decrease in trophozoite growth after a 12 h exposure to 500 μg/mL of EOP, while complete parasite death was induced at 24 h. With regard to CHO-K1 cells, the CC₅₀ was 266 μg/mL, and 92% cytotoxicity was observed after exposure to 500 μg/mL of EOP. Otherwise, a concentration of 200 μg/mL of EOP was able to reduce parasite proliferation by 70% and was not cytotoxic to CHO-K1 cells. As an adjuvant, a synergistic effect was observed when EOP was combined with the rCP40 protein (G3) in comparison to the administration of each component alone (G1 and G2), resulting in higher concentrations of IgG, IgG1 and IgG2a. EOP is constituted by biologically active components with promising antiparasitic and immunostimulatory activities and can be investigated for the formulation of new vaccines or trichomonacidal drugs.

Trichomonicidal and parasite membrane damaging activity of bidesmosic saponins from Manilkara rufula

The infection caused by Trichomonas vaginalis is the most common but overlooked non-viral sexually transmitted disease worldwide. Treatment relies on one class of drugs, the 5-nitroimidazoles, but resistance is widespread. New drugs are urgently needed. We reported the effect of crude and purified saponin fractions of Manilkara rufula against Trichomonas vaginalis. The compound responsible for antitrichomonal activity was isolated and identified as an uncommon bidesmosic saponin, Mi-saponin C. This saponin eliminated parasite viability without toxicity against the human vaginal epithelial line (HMVII). In addition, the isolated saponin fraction improved the metronidazole effect against a metronidazole-resistant isolate and dramatically reduced the cytoadherence of T. vaginalis to human cells. Investigation of the mechanism of death showed that the saponin fraction induced the parasite death due to profound membrane damage, inducing a disturbance of intracellular content without nuclear damage. To the best of our knowledge, this is the first report of antitrichomonal activity in the bidesmosic saponins of Manilkara rufula.

Synthesis, antiprotozoal activity, and chemoinformatic analysis of 2-(methylthio)-1H-benzimidazole-5-carboxamide derivatives: Identification of new selective giardicidal and trichomonicidal compounds

A series of twelve new 2-(methylthio)-1H-benzimidazole-5-carboxamide derivatives (1-12) were synthesized and their antiparasitic activity was tested in vitro against Giardia intestinalis, Trichomonas vaginalis and Entamoeba histolytica. Experimental evaluations showed IC₅₀ values within the nanomolar range for all tested compounds, some showing higher activity than metronidazole and albendazole. A chemoinformatic study was used to compare the structure-activity relationship of the synthesized carboxamides with those of 91 previously studied benzimidazoles, and with some Nitazoxanide-N-methylbenzimidazole hybrids recently synthetized by our group. Compounds 1 and 3 were identified as prominent selective compounds against T. vaginalis and G. intestinalis, respectively, while compound 4 was found to be of broad spectrum against the three protozoans.

Potential of synthetic endoperoxides against Trichomonas vaginalis in vitro

Metronidazole is well known for medicine against Trichomonas vaginalis infection, but it has side effects though it is effective, and especially because reports of metronidazole-tolerant species are increasing, the development of new medicine is being required. Here, we noticed the killing effects of endoperoxide compounds, N-89 and N-251 as new antimalarial drug candidates, on T. vaginalis and searched the possibility of development of new medicine. We added each of metronidazole, artemisinin, and two of new endoperoxides (N-89 and N-251) to metronidazole-resistant and -sensitive species and compared its anti-trichomonal efficacy. For metronidazole, IC₅₀ value, 50% of killing concentration for T. vaginalis, was very low for metronidazole-sensitive isolates (11.7 to 22.8μM), but was high for metronidazole-resistant ones (182.9 to 730.4μM). The IC₅₀ values of N-89 and N-251 were 41.0 to 60.0μM, and 82.0 to 300.0μM for metronidazole-sensitive and -resistant isolates, respectively. In conclusion, we found the endoperoxides, N-89 and N-251, have anti-trichomonal effect against metronidazole-resistant T. vaginalis as well as metronidazole-sensitive ones. These results indicate that the anti-trichomonal effects for our endoperoxides are equivalent or better in metronidazole-resistant T. vaginalis in comparison to metronidazole.

Evaluating the utility of syndromic case management for three sexually transmitted infections in women visiting hospitals in Delhi, India

Utility of syndromic case management (SCM) in women visiting obstetrics & gynecology department needs to be evaluated as it is subjective and imperfect. Consequently, antibiotic resistance has accelerated along with increased risk of infection to the partners. To understand the effectiveness and/or inadequacies of SCM, 11000 women were recruited and examined by clinicians for infection by Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), Trichomonas vaginalis (TV), Bacterial vaginosis (BV) and others. Amongst these patients, 1797 (16.3%) reported vaginal discharge (VD). Other symptoms included: vaginitis (97%), cervicitis (75%), genital ulcers (60%), abnormal vaginal discharge (55%) and lower abdominal pain (48%). The patients were treated for single or co-infections using pre-packed National Aids Control Program III STI/RTI Kits. However, based on PCR diagnostics, 1453/1797 (81%) subjects were uninfected for NG/TV/CT. Amongst 344 (19%) infected patients, 257 (75%) carried infection with single pathogen (TV/NG/CT) while 87/344 (25%) were co-infected with multiple pathogens. Prevalence of TV, NG & CT was 4%, 7% and 8% respectively. Co-infection with CT + NG was highest, 51% (44/87), whereas, co-infection with CT + TV was 21% and NG + TV was 18% while co-infection with all three pathogens was 1.3%. We conclude that SCM is imprecise and successful intervention requires accurate and confirmatory diagnostic approach.

Morphological Changes of Trichomonas vaginalis Treated by Ornidazole: An In-Vitro Study

BACKGROUND

Nitroimidazoles, which are drugs that are used to effectively treat Trichomonas vaginalis, alter the structure of the T. vaginalis cell membrane, penetrate into its cytoplasm and nucleus and block cellular metabolism. In this study, we observed the morphological changes that occurred in T. vaginalis during in vitro exposure to 1.3 μg/mL of ornidazole at various time intervals ranging from 10 minutes to 10 hours.

METHODS

Vaginal and urethral secretion samples from suspected T. vaginalis cases were inoculated into Cysteine Peptone Liver Maltose medium. In 18 sterile tubes, 9.5 mL of this solution were mixed with 0.5 mL of ornidazole. The periods of contact between ornidazole and T. vaginalis ranged from 10 minutes to 10 hours.

RESULTS

The first change was vacuolization, which started in the 10th minute of exposure. The glycogen particles started to diminish in the 20th minute.

CONCLUSIONS

During exposure to 1.3 mg/L of ornidazole, cell lysis began in the 30th minute and accelerated towards the 60th minute (p < 0.001). Cytoplasmic matrix integrity was impaired in the 60th minute (p < 0.001).

Recalcitrant Trichomonas vaginalis infection – a case series

The objective of this study was (1) to estimate the prevalence of recalcitrant Trichomonas vaginalis (TV) infection in a UK genitourinary medicine clinic; (2) to use a case series and literature review to suggest an algorithm for management of recalcitrant TV (rTV). A retrospective review of laboratory records, case-notes and literature review was conducted. Fifteen patients were studied, representing 1.16% of the cases presenting during the study period. A wide variety of therapeutic agents was used, the treatment regimen differed for each patient. No treatment was universally effective in achieving cure, but the use of acetarsol pessaries vaginally appeared to be the most frequently successful strategy. Based on these results, an algorithm for treatment of rTV is presented, although clinical trials will be needed to elucidate the best clinical approaches to this problem.

Trichomonas vaginalis NTPDase and ecto-5'-nucleotidase hydrolyze guanine nucleotides and increase extracellular guanosine levels under serum restriction

Trichomonas vaginalis is the aethiologic agent of trichomoniasis, the most common non-viral sexually transmitted disease in the world. The purinergic signaling pathway is mediated by extracellular nucleotides and nucleosides that are involved in many biological effects as neurotransmission, immunomodulation and inflammation. Extracellular nucleotides can be hydrolyzed by a family of enzymes known as ectonucleotidases including the ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDases) family which hydrolyses nucleosides triphosphate and diphosphate as preferential substrates and ecto-5'-nucleotidase which catalyzes the conversion of monophosphates into nucleosides. In T. vaginalis the E-NTPDase and ecto-5'-nucleotidase activities upon adenine nucleotides have already been characterized in intact trophozoites but little is known concerning guanine nucleotides and nucleoside. These enzymes may exert a crucial role on nucleoside generation, providing the purine sources for the synthesis de novo of these essential nutrients, sustaining parasite growth and survival. In this study, we investigated the hydrolysis profile of guanine-related nucleotides and nucleoside in intact trophozoites from long-term-grown and fresh clinical isolates of T. vaginalis. Knowing that guanine nucleotides are also substrates for T. vaginalis ectoenzymes, we evaluated the profile of nucleotides consumption and guanosine uptake in trophozoites submitted to a serum limitation condition. Results show that guanine nucleotides (GTP, GDP, GMP) were substrates for T. vaginalis ectonucleotidases, with expected kinetic parameters for this enzyme family. Different T. vaginalis isolates (two from the ATCC and nine fresh clinical isolates) presented a heterogeneous hydrolysis profile. The serum culture condition increased E-NTPDase and ecto-5'-nucleotidase activities with high consumption of extracellular GTP generating enhanced GDP, GMP and guanosine levels as demonstrated by HPLC, with final accumulation of the nucleoside. The transcript levels of the five TvNTPDases gene sequences were analyzed by qRT-PCR and the highest gene expressions were found for TvNTPDase 2 and 4. The extracellular guanosine uptake was observed as (13C)GTP nucleotide into parasite DNA and it was lower than that observed for adenosine, labeled as (13C)ATP. These findings indicate the T. vaginalis preference for adenosine uptake and the accumulation of guanosine in the extracellular milieu, corroborating with HPLC data. Our data demonstrate, for the first time, the cascade of guanine nucleotides in T. vaginalis and open possibilities on the study of guanine-related purines other than the classical intracellular activity of G proteins for signal transduction.

Evaluation of the in vitro activity of ceragenins against Trichomonas vaginalis

Trichomonosis, caused by the protozoan parasite Trichomonas vaginalis, is a curable sexually transmitted disease that is most commonly encountered worldwide. Increasing importance of trichomoniasis and emerging of resistance against metronidazole lead to search for alternative drugs with different mode of activity. The purpose of this study was to determine in vitro activity of ceragenins (CSA-13, CSA-44, CSA-13, and CSA-138) against the metronidazole-susceptible (ATCC 30001) and metronidazole-resistant (ATCC 50138) strains of T. vaginalis. The effective concentrations were evaluated using two strains of T. vaginalis with different metronidazole susceptibilities (ATCC 30001 and ATCC 50138) in the presence of dilution series of ceragenins in 24-well microtitre assays. Overall, all the ceragenins killed the metronidazole-susceptible (ATCC 30001) and metronidazole-resistant (ATCC 50138) strains of T. vaginalis (p>0.05). With regard to the their effects against the studied strains of T. vaginalis, in order of effectiveness, overall, the ceragenins ordered as CSA-13 (the most effective), CSA-131 and CSA-138 (effective similarly), and CSA-44 (the least effective) (p<0.05). All of the ceragenins reduced the trophozoite numbers of both of studied strains of T. vaginalis with a time- and dose- dependent manner (p<0.05). Although all of the study ceragenins, CSA-13, CSA-44, CSA-13, and CSA-138, killed the studied strains of T. vaginalis. CSA-13 is the leading ceragenin as the most effective anti-trichomonas compound, followed by CSA-131 and CSA-138. They have a potential to have a place in the armemantarium of gynecologic and urologic practice for the management of sexually transmitted diseases.

[In vitro susceptibility of Trichomonas vaginalis to metronidazole, ornidazole and proton pump inhibitors pantoprazole and esomeprazole]

The current treatment of trichomoniasis is based on the use of 5-nitroimidazole derivatives. Although metronidazole is reliable, inexpensive and highly effective against anaerobic microorganisms and protozoa, the development of metronidazole-resistant T.vaginalis strains pose to an increasing problem. Nitroimidazoles are compounds having azomycin (2-nitroimidazole) chemical structure and are obtained from Streptomyces strains. Benzimidazole, which is found in the structure of proton pump inhibitors, is also present in the other components that have antiprotozoal activity. In this study, the in vitro susceptibility of T.vaginalis against metronidazole, ornidazole, and the proton pump inhibitors which are tested recently as antiprotozoal agents; pantoprazole and esomeprazole was investigated. For this purpose a clinical T.vaginalis strain which was formerly isolated and stored after cryopreservation process in our laboratory was used. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) values of those agents against to this strain were determined in vitro by dilution method in 24-well cell culture plates. Trypticase yeast extract maltose medium, horse serum and antibiotic (penicillin + streptomycin) were distributed to each well of cell culture plates and after metronidazole, ornidazole, pantoprazole and esomeprazole solutions were added to two wells for each as 800, 400, 200, 100, 50 and 25 µg/ml, followed by the addition of 1 ml 5x10(3) T.vaginalis trophozoites into each well. Plates were incubated at 37°C, and viability and motility of the trophozoites were evaluated under light microscope at 24, 48 and 72 hours after incubation. MIC and MLC values of metronidazole/ornidazole in the 72(th) hour were found as 50 µg/ml and 100 µg/ml, respectively. MIC and MLC values for pantoprazole in the 72th hour were 200 µg/ml and 400 µg/ml, while the values for esomeprazole were 400 µg/ml ve 800 µg/ml, respectively. As a result, T.vaginalis strain used in the study was susceptible to metronidazole and ornidazole, besides, it was considered that pantoprazole and esomeprazole were also effective to the parasite and could be used as alternative drugs. However, further in vitro and clinical studies are clearly needed on the antiprotozoal effects of proton pump inhibitors. To our knowledge, this study was the first in literature, which esomeprazole's susceptibility on T.vaginalis was investigated in vitro.

Anti-Trichomonas vaginalis properties of the oil of Amomum tsao-ko and its major component, geraniol

CONTEXT

Trichomonosis, caused by the flagellate protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease (STD) and 5-nitroimidazole drugs are used for the treatment. However, a growing number of T. vaginalis isolates are resistant to these drugs, which make it becomes an urgent issue.

OBJECTIVE

The current study was designed to evaluate the anti-T. vaginalis activity of the essential oil from A. tsao-ko used in traditional Chinese medicine and as a spice and its main component, geraniol.

MATERIALS AND METHODS

The anti-T. vaginalis activities of A. tsao-ko essential oil and geraniol were evaluated by the minimum lethal concentration (MLC) and 50% inhibitory concentration (IC50) in vitro. The morphological changes of T. vaginalis were observed by transmission electron microscopy (TEM). Additionally, sub-MLC concentration treatment with sub-MLC A. tsao-ko essential oil and geraniol was also performed.

RESULTS

This study shows that MLC/IC50 of A. tsao-ko essential oil was 44.97 µg/ml/22.49 µg/ml for T. vaginalis isolate Tv1, and 89.93 µg/ml/44.97 µg/ml for T. vaginalis isolate Tv2. Those of geraniol were 342.96 µg/ml/171.48 µg/ml, respectively. After A. tsao-ko essential oil or geraniol treatment, obvious similar morphological changes of T. vaginalis were observed by TEM: the nuclear membrane was damaged, nuclei were dissolved, and the chromatin was accumulated; in the cytoplasm, numerous vacuoles appeared, rough endoplasmic reticulum dilated, the number of ribosomes were reduced, organelles disintegrated, the cell membrane was partially damaged, with cytoplasmic leakage, and cell disintegration was observed. The action time did not increase the effect of A. tsao-ko essential oil or geraniol against T. vaginalis, as no significant difference was observed after sub-MLC concentration treatment for 1, 3, and 5 h with A. tsao-ko essential oil and geraniol.

DISCUSSION AND CONCLUSION

The study describes the first report on the activity and morphological changes of A. tsao-ko essential oil and geraniol against T. vaginalis. The results obtained herein presented new opportunities for antitrichomonal drugs.

Protocols for the routine screening of drug sensitivity in the human parasite Trichomonas vaginalis

Trichomonas vaginalis is a sexually transmitted protozoan parasite of humans. Treatment of trichomoniasis is almost completely dependent on the old drug metronidazole and is hampered by resistance. New drug development, like routine screening for drug resistance, has however been hampered by the lack of reliable screening protocols with sufficient throughput. Here we report on two separate in vitro protocols that use fluorescent dyes and allow for standardized drug sensitivity testing on the required scale.

Trichonomas vaginalis metalloproteinase induces apoptosis of SiHa cells through disrupting the Mcl-1/Bim and Bcl-xL/Bim complexes

To elucidate the roles of metalloproteinases and the Bcl-2 family of proteins in Trichovaginalis. vaginalis-induced apoptosis in human cervical cancer cells (SiHa cells) and vaginal epithelial cells (MS74 cells), SiHa cells and MS74 cells were incubated with live T. vaginalis, T. vaginalis excretory and secretory products (ESP), and T. vaginalis lysates, either with or without the specific metalloproteinase inhibitor 1,10-phenanthroline (1,10-PT), and examined apoptotic events and Bcl-2 signaling. The live T. vaginalis and the T. vaginalis ESP induced the release of cytochrome c into the cytosol, the activation of caspase-3 and caspase-9, and the cleavage of PARP. Additionally, the live T. vaginalis, but not the T. vaginalis lysate, induced the cleavage of the proapoptotic Bim protein. The live T. vaginalis and the T. vaginalis ESP, but not the T. vaginalis lysate, induced the dose-dependent cleavage of the antiapoptotic Bcl-xL and Mcl-1 proteins and decreased the association levels of Bcl-xL/Bim and Mcl-1/Bim complexes. We performed gelatin zymography and casein-hydrolysis assays on the live T. vaginalis and the T. vaginalis ESP to identify the apoptosis-inducing factor. Both the live T. vaginalis and the ESP contained high levels of metalloproteinases, of which activities were significantly inhibited by 1,10-PT treatment. Furthermore, the 1,10-PT blocked the cleavage of Bcl-xL, Mcl-1, PARP, caspase-3, and caspase-9, as well as the release of cytochrome c into the cytosol, and it significantly increased the association levels of the Bcl-xL/Bim and Mcl-1/Bim protein complexes, returning them to normal levels. Our results demonstrate that T. vaginalis induces mitochondria-dependent apoptosis in SiHa cells through the dissociation of Bcl-xL/Bim and Mcl-1/Bim complexes and that the apoptosis is blocked by the metalloproteinase inhibitor 1,10-PT. These results expand our understanding of the role of metalloproteinases in T. vaginalis-induced apoptosis and the signaling pathway in trichomoniasis of the cervicovaginal epithelial cells.

Anti-Trichomonas vaginalis activity from triterpenoid derivatives

Trichomonas vaginalis is a flagellated parasite that causes trichomonosis, the most common non-viral sexually transmitted disease (STD) in the world. Worryingly, trichomonosis is associated to increased transmission of HIV. Due to high frequency of the infection during pregnancy and the development of metronidazole-resistant isolates, therapeutic alternatives to 5-nitroimidazole are being searched. Triterpenes are natural products presenting several biological activities such as anti-protozoal activity. The aim of this study was to evaluate the in vitro anti-T. vaginalis activity from betulinic and ursolic acids, as well as semisynthetic derivatives obtained. Compounds obtained from betulinic acid presented better activity than those from ursolic acid. Piperazine derivatived from betulinic acid presented minimum inhibitory concentration (MIC) value of 91.2 μM, and the kinetic growth curve performed with parasites treated with this most active compound revealed complete inhibition of trophozoite proliferation at 2 h of incubation and total abolition of trophozoite growth in 24 h, revealing that the piperazine derivative is an efficient trichomonacidal molecule. The same compound promoted total erythrocyte lysis and lactate dehydrogenase (LDH) liberation of 83 and 100% (at 45.6 and 91.2 μM, respectively), indicating parasite membrane damage. The piperazine derivative demonstrated cytotoxic effect against the HMVII and HeLa cell lineages at the MIC value. This is the first report of semisynthetic triterpenoid derivatives with anti-T. vaginalis activity, revealing the high potential of these compounds as trichomonacidal agents.

ComparativeIn VitroCytotoxic Effects of Ornidazole, Metronidazole and Ciprofloxacin againstTrichomonas vaginalisTrophozoites

A strain of Trichomonas vaginalis, isolated from a patient complaining of vaginal discharge, was incubated and cultivated to compare the in vitro effects of ornidazole, metronidazole and ciprofloxacin on T. vaginalis trophozoites in terms of minimal inhibition concentrations (MICs) and minimal lethal concentrations (MLCs). MIC levels at 24 hours for ornidazole, metronidazole and ciprofloxacin were 50 mg/mL, 50 mg/mL, and 750 mg/mL. Corresponding MLC levels were the same. In this in vitro study, ornidazole was found to be the most effective drug among 3 drugs tested against T. vaginalis trophozoites in terms of MIC and MLC levels. It is interesting to note that ciprofloxacin, although not as effective as the others, also had some cytotoxic effect on T. vaginalis trophozoites.

TvMP50 is an immunogenic metalloproteinase during male trichomoniasis

Trichomonas vaginalis, a human urogenital tract parasite, is capable of surviving in the male microenvironment, despite of the presence of Zn(2+). Concentrations > 1.6 mM of Zn(2+) have a trichomonacidal effect; however, in the presence of ≤1.6 mM Zn(2+), several trichomonad proteins are up- or down-regulated. Herein, we analyzed the proteome of a T. vaginalis male isolate (HGMN01) grown in the presence of Zn(2+) and found 32 protein spots that were immunorecognized by male trichomoniasis patient serum. Using mass spectrometry (MS), the proteins were identified and compared with 23 spots that were immunorecognized in the proteome of a female isolate using the same serum. Interestingly, we found a 50-kDa metallopeptidase (TvMP50). Unexpectedly, this proteinase was immunodetected by the serum of male trichomoniasis patients but not by the female patient serum or sera from healthy men and women. We analyzed the T. vaginalis genome and localized the mp50 gene in locus TVAG_403460. Using an RT-PCR assay, we amplified a 1320-bp mp50 mRNA transcript that was expressed in the presence of Zn(2+) in the HGMN01 and CNCD147 T. vaginalis isolates. According to a Western blot assay, native TvMP50 was differentially expressed in the presence of Zn(2+). The TvMP50 proteolytic activity increased in the presence of Zn(2+) in both isolates and was inhibited by EDTA but not by ptosyl-L-lysine chloromethyl ketone (TLCK), E64, leupeptin, or phenylmethane sulfonyl fluoride. Furthermore, the recombinant TvMP50 had proteolytic activity that was inhibited by EDTA. These data suggested that TvMP50 is immunogenic during male trichomoniasis, and Zn(2+) induces its expression.

[Complex personalized therapy of patients with chlamydiosis taking into consideration abnormalities of pro-oxidant-antioxidant and immune systems]

A new original, pathogenetically relevant method of complex differentiated treatment of chlamydial urogenital disorders was developed with the consideration of prooxidant-antioxidant and immune systems statuses. That provides a personalized usage in the treatment plan modern azalide antibiotic azithromycin and immunomodulator herbal drug manax taking into the account clinical course of the disease.

A prospective cohort study comparing the effect of single-dose 2 g metronidazole on Trichomonas vaginalis infection in HIV-seropositive versus HIV-seronegative women

BACKGROUND

This analysis compared the frequency of persistent Trichomonas vaginalis (TV) among HIV-seropositive and HIV-seronegative women.

METHODS

Data were obtained from women enrolled in an open cohort study of sex workers in Kenya. Participants were examined monthly, and those diagnosed as having TV by saline microscopy were treated with single-dose 2 g oral metronidazole. All women on antiretroviral therapy (ART) used nevirapine-based regimens. Generalized estimating equations with a logit link were used to compare the frequency of persistent TV (defined as the presence of motile trichomonads by saline microscopy at the next examination visit within 60 days) by HIV status.

RESULTS

Three-hundred sixty participants contributed 570 infections to the analysis (282 HIV-seropositive and 288 HIV-seronegative). There were 42 (15%) persistent infections among HIV-seropositive participants versus 35 (12%) among HIV-seronegative participants (adjusted odds ratio, 1.14; 95% confidence interval [CI], 0.70-1.87). Persistent TV was highest among HIV-seropositive women using ART (21/64 [33%]) compared with HIV-seropositive women not using ART (21/217 [10%]). Concurrent bacterial vaginosis (BV) at TV diagnosis was associated with an increased likelihood of persistent TV (adjusted odds ratio, 1.90; 95% confidence interval, 1.16-3.09).

CONCLUSIONS

The frequency of persistent TV infection after treatment with single-dose 2 g oral metronidazole was similar by HIV status. Alternative regimens including multiday antibiotic treatment may be necessary to improve cure rates for women using nevirapine-based ART and women with TV and concurrent BV.

Trichomonas vaginalis vaginitis in obstetrics and gynecology practice: new concepts and controversies

Trichomonas vaginalis (TV) is the most common curable sexually transmitted infection worldwide. Annually, 7.4 million new infections are estimated in the United States, which is greater than combined new cases of Chlamydia, gonorrhea, and syphilis. Serious adverse reproductive health outcomes including pregnancy complications, pelvic inflammatory disease, and an increased risk of HIV acquisition have been linked to TV infection. There are several sensitive and specific diagnostic tests available, including a newly approved nucleic acid amplification test (NAAT) that utilizes the same instrumentation platform and clinical sample as Chlamydia and gonorrhea tests. In this article, we review TV pathogenicity, adverse reproductive health outcomes, detection, and treatment followed by clinical scenarios for which TV diagnosis may prove useful in obstetrics and gynecology practice.

The antimicrobial peptide, shrimp anti-lipopolysaccharide factor (SALF), inhibits proinflammatory cytokine expressions through the MAPK and NF-κB pathways in Trichomonas vaginalis adherent to HeLa cells

Trichomonas vaginalis is a parasitic protozoan that causes sexually transmitted infections (STIs) worldwide. The infection is dangerous and easily spreads within a community. Also, some cases of drug resistance were reported. Previously, we reported that the shrimp anti-lipopolysaccharide factor (SALF), an antimicrobial peptide of 24 amino acids, modulates inflammatory responses and inhibits T. vaginalis growth. To date, there is no report on the mechanism of SALF's actions in T. vaginalis' adherence to HeLa cells. In this research using an ELISA, we found that the SALF downregulated the release of proinflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1α, IL-6, IL-8, and monocyte chemoattractant protein (MCP)-1) secreted by T. vaginalis which was adhering to HeLa cells. We also performed real-time PCR experiments to determine the roles of the SALF in the expressions of several proinflammatory genes. Through a Western blot analysis, we determined that SALF treatment inhibited T. vaginalis-treated HeLa cells through the p38 and NF-κB pathways. Furthermore, we used different inhibitors to confirm the pathway by ELISA and Western blotting. Taken together, it is apparent that the SALF suppresses T. vaginalis-induced secretion of proinflammatory cytokines by HeLa cells by acting through the p38 and NF-κB pathways.

Endobiont viruses sensed by the human host - beyond conventional antiparasitic therapy

Wide-spread protozoan parasites carry endosymbiotic dsRNA viruses with uncharted implications to the human host. Among them, Trichomonas vaginalis, a parasite adapted to the human genitourinary tract, infects globally ∼250 million each year rendering them more susceptible to devastating pregnancy complications (especially preterm birth), HIV infection and HPV-related cancer. While first-line antibiotic treatment (metronidazole) commonly kills the protozoan pathogen, it fails to improve reproductive outcome. We show that endosymbiotic Trichomonasvirus, highly prevalent in T. vaginalis clinical isolates, is sensed by the human epithelial cells via Toll-like receptor 3, triggering Interferon Regulating Factor -3, interferon type I and proinflammatory cascades previously implicated in preterm birth and HIV-1 susceptibility. Metronidazole treatment amplified these proinflammatory responses. Thus, a new paradigm targeting the protozoan viruses along with the protozoan host may prevent trichomoniasis-attributable inflammatory sequelae.

[Mycoplasma hominis symbiosis and Trichomonas vaginalis metronidazole resistance]

OBJECTIVE

To investigate the relation of Mycoplasma hominis symbiosis and the resistance of Trichomonas vaginalis to metronidazole.

METHODS

From November 2010 to July 2011, 160 isolates of T. vaginalis were collected from the genital tract secretion of gynecological out-patients at the Sichuan Provincial Hospital for Women and Children. The minimum lethal concentration (MLC) to metronidazole of these isolates was determined by an in vitro sensitivity assay with different concentration gradients of metronidazole (from 1 to 1 024 microg/ml), and M. hominis DNA in T. vaginalis was detected by polymerase chain reaction (PCR) technique with specific 16S rRNA primers. After clearance of M. hominis from the parasites by 32 microg/ml doxycycline, MLC was determined and compared with that before clearance.

RESULTS

MLC of metronidazole in T. vaginalis ranged from 1 to 256 microg/ml, with 61.3% isolates (98/160) ranging from 1 to 8 microg/ml, 26.3% isolates (42/160) ranging from 16 to 32 microg/ml, and 12.5% isolates (20/160) ranging from 64 to 256 microg/ml. 61 isolates were PCR positive for M. hominis DNA in the 160 isolates of T. vaginalis. The M. hominis DNA positive rate was significantly higher in the T. vaginalis isolates with higher MLC than those isolates with lower MLC (P<0.01). However, when M. hominis was cleared by doxycycline from 8 isolates among the 61 ones, no change was observed in sensitivity of the isolates to metronidazole.

CONCLUSION

M. hominis symbiosis might be associated with the metronidazole-resistance of T. vaginalis. However, it needs direct evidence.

In vitro antimicrobial activity of Persian shallot (Allium hirtifolium)

Allium hirtifolium is a Persian native plant grown in cool mountain slopes of Iran. It has been used as a spice in Iran for many years. According to the literature review, there are no considerable reports on the antimicrobial properties of this plant. In this study, the antimicrobial activity of Persian shallot hydroalcoholic extract and F1 fraction of the plant (containing amino acid derivatives and/or other cationic compounds) was investigated on some Gram positive cocci and bacilli, Gram negative bacilli, two protozoa, a yeast and a fungus. Excellent activity against Candida albicans (MIC = 64 microg/ml, MBC = 128 microg/ml), Leishmania infantum (MIC = 0.2 mg/ml on the first day of study) and Trichomonas vaginalis (MIC = 5 microg/ml in PSDE form) and a moderate activity against Bacillus spp and Pseudomonas aeroginosa (MIC = 128 microg/ml) was observed. The results showed that this plant contains some anti-trichomonas and anti-leishmania components.

Extensive genetic diversity, unique population structure and evidence of genetic exchange in the sexually transmitted parasite Trichomonas vaginalis

Background

Trichomonas vaginalis is the causative agent of human trichomoniasis, the most common non-viral sexually transmitted infection world-wide. Despite its prevalence, little is known about the genetic diversity and population structure of this haploid parasite due to the lack of appropriate tools. The development of a panel of microsatellite makers and SNPs from mining the parasite's genome sequence has paved the way to a global analysis of the genetic structure of the pathogen and association with clinical phenotypes.

Methodology/Principal Findings

Here we utilize a panel of T. vaginalis-specific genetic markers to genotype 235 isolates from Mexico, Chile, India, Australia, Papua New Guinea, Italy, Africa and the United States, including 19 clinical isolates recently collected from 270 women attending New York City sexually transmitted disease clinics. Using population genetic analysis, we show that T. vaginalis is a genetically diverse parasite with a unique population structure consisting of two types present in equal proportions world-wide. Parasites belonging to the two types (type 1 and type 2) differ significantly in the rate at which they harbor the T. vaginalis virus, a dsRNA virus implicated in parasite pathogenesis, and in their sensitivity to the widely-used drug, metronidazole. We also uncover evidence of genetic exchange, indicating a sexual life-cycle of the parasite despite an absence of morphologically-distinct sexual stages.

Conclusions/Significance

Our study represents the first robust and comprehensive evaluation of global T. vaginalis genetic diversity and population structure. Our identification of a unique two-type structure, and the clinically relevant phenotypes associated with them, provides a new dimension for understanding T. vaginalis pathogenesis. In addition, our demonstration of the possibility of genetic exchange in the parasite has important implications for genetic research and control of the disease.

The human parasite Trichomonas vaginalis causes trichomoniasis, the world's most common non-viral sexually transmitted infection. Research on T. vaginalis genetic diversity has been limited by a lack of appropriate genotyping tools. To address this problem, we recently published a panel of T. vaginalis-specific genetic markers; here we use these markers to genotype isolates collected from ten regions around the globe. We detect high levels of genetic diversity, infer a two-type population structure, identify clinically relevant differences between the two types, and uncover evidence of genetic exchange in what was believed to be a clonal organism. Together, these results greatly improve our understanding of the population genetics of T. vaginalis and provide insights into the possibility of genetic exchange in the parasite, with implications for the epidemiology and control of the disease. By taking into account the existence of different types and their unique characteristics, we can improve understanding of the wide range of symptoms that patients manifest and better implement appropriate drug treatment. In addition, by recognizing the possibility of genetic exchange, we are more equipped to address the growing concern of drug resistance and the mechanisms by which it may spread within parasite populations.

Trichomoniasis: evaluation to execution

Trichomoniasis is the most common sexually transmitted disease, caused by a motile flagellate non-invasive parasitic protozoan, Trichomonas vaginalis (T. vaginalis). More than 160 million people worldwide are annually infected by this protozoan. T. vaginalis occupies an extracellular niche in the complex human genito-urinary environment (vagina, cervix, penis, prostate gland, and urethra) to survive, multiply and evade host defenses. T. vaginalis (strain G3) has a ∼160 megabase genome with 60,000 genes, the largest number of genes ever identified in protozoans. The T. vaginalis genome is a highly conserved gene family that encodes a massive proteome with one of the largest coding (expressing ∼4000 genes) capacities in the trophozoite stage, and helps T. vaginalis to adapt and survive in diverse environment. Based on recent developments in the field, we review T. vaginalis structure, patho-mechanisms, parasitic virulence, and advances in diagnosis and therapeutics.

Activity of Cuban propolis extracts on Leishmania amazonensis and Trichomonas vaginalis

In this paper we analyzed the antiprotozoal effects of eighteen Cuban propolis extracts (brown, red and yellow type) collected in different geographic areas, using Leishmania amazonensis (as a model of intracellular protozoa) and Trichomonas vaginalis (as a model of extracellular protozoa). All evaluated propolis extracts caused inhibitory effect on intracellular amastigotes of L. amazonensis. However, cytotoxicity on peritoneal macrophages from BALB/c mice was observed. Only five samples decreased the viability of T. vaginalis trophozoites at concentrations lower than 10 microg/mL. No correlation between the type of propolis and antiprotozoal activity was found. Cuban propolis extracts demonstrated activity against both intracellular and extracellular protozoa model, as well as the potentialities of propolis as a natural source to obtain new antiprotozoal agents.

Screening and bioguided fractionation of Amaryllidaceae species with anti-Trichomonas vaginalis activity

The Amaryllidaceae family is known by its ornamental and medicinal value and has attracted considerable attention due to the content of alkaloids of its species, which showed interesting biological properties. The present study evaluated the anti-Trichomonas vaginalis activity of eighteen extracts (12.5 to 0.19 mg/mL) and six isolated alkaloids (125 to 1.9 µg/mL) from Amaryllidaceae species. The alkaloids diminished the trophozoites viability (from 15 to 40 %). The extracts from Hippeastrum breviflorum demonstrated the highest anti-T. vaginalis activity (viability was 60 % reduced), and a bioguided study was conducted. Six fractions with antiprotozoal activity had lycorine and lycosinine as major components suggesting a synergistic effect, taking into account the higher anti-T. vaginalis activity of extracts when compared to isolated alkaloids. Our results point out the antiprotozoal potential of the Amaryllidaceae species against T. vaginalis. This parasite causes trichomonosis, the most prevalent nonviral sexually transmitted diseases (STD) worldwide and a public health problem that requires new therapeutic alternatives as well bioactive natural products.

[Development and use of test systems for the evaluation of sensitivity of Trichomonas vaginalisto preparations of the 5-nitroimidazole and 5-nitrofuran groups]

AIM

Development of test system for the evaluation of sensitivity of Trichomonas vaginalis to preparations of the 5-nitroimidazole and 5-nitrofuran groups.

MATERIALS AND METHODS

Determination of minimal cidic concentration (MCC) of antiprotozoal preparations was carried out by cultivating laboratory T. vaginalis strains in wells of plates with nutrient medium containing varying concentrations of these preparations. Evaluation of vitality of the agent was determined by using trypan blue vital stain and bysubsequent growth ability in nutrient medium without antiprotozoal preparations. Construction of the test system was carried out by selecting conditions for the fixation of preparations in the plate wells and control of activity retention after the fixation. 109 isolates from patients with confirmed trichomoniasis diagnosis were used for the approbation of the test system.

RESULTS

Cultivation of 10 strains showed that MCC of investigated preparations had the following values: metronidazole 5, tinidazole 1.25; secnidazole 2.5; nimorazole 1.25; ornidazole 2.5; clotrimazole 15; nifuratel 1.25 microg/ml. Studies of clinical material revealed single-type sensitivity of strains isolated during acute trichomoniasis, and varying--during chronic, while one strain had multidrug resistance.

CONCLUSION

A simple test system available for routine laboratory work for the evaluation of sensitivity of T. vaginalis to preparations of the 5-nitroimidazole and 5-nitrofuran groups was developed. The efficacy of the test ensures high sensitivity, reproducibility and shorter procedure time as compared with classical method, thus allowing the selection of preparation for therapy with the highest probability.

Lycorine induces cell death in the amitochondriate parasite, Trichomonas vaginalis, via an alternative non-apoptotic death pathway

In this study, the mechanism of action of the pro-apoptotic alkaloid lycorine on an amitochondriate cell, the parasite Trichomonas vaginalis, was investigated. The cytotoxicity of lycorine against T. vaginalis was studied from 2.5 to 1000μM and several important ultrastructural alterations were observed by electron microscopy. Lycorine arrested the T. vaginalis cell cycle, although no hallmarks of apoptosis, such as apoptotic bodies, were observed. Consequently, the underlying mechanism of action fails to completely fulfill the criteria for apoptosis. However, some similarities to paraptotic cell death were observed.

[In vitro anti-Trichomonas vaginalis effects of a mixture of dihydroartemisinin and metronidazole]

OBJECTIVE

To observe the effect of a mixture of dihydroartemisinin and metronidazole on ultrastructure of Trichomonas vaginalis trophozoites in vitro for exploring trichomonacidal mechanism of the drug mixture.

METHODS

The trophozoites were cultivated with liver extract solution medium that contained 2.5 x 10(6) parasites/ml. There were dihydroartemisinin 0.5 mg/ml and metronidazole 0.002 mg/ml in the experimental tubes of the drug mixture group. Groups of control (without drug), dihydroartemisinin (1 mg/ml) and metronidazole (5 mg/ml) were established and performed in the same experimental conditions. The parasites were observed by scanning and transmission electron microscopes after having treated with the drugs at 37 degrees for 3.5-5 h.

RESULTS

Under scanning electron microscope, the cell membrane of T. vaginalis treated only with dihydroartemisinin for 35 h was damaged, part of pellicle peeled off. Although the surface of the trophozoites treated only with metronidazole for 5 h showed many small bubbles and hollows, the cell membrane looked integral. However, surface of the parasite exposed to the drug mixture for 3.5-4.2 h showed deep folds and cracks, the cell membrane was damaged and even peeled off. When the cell ruptured, the nucleus, axostyle, pelta and hydrogenosomes were exposed, and the cytoplasm spilled out. Transmission electron microscopy showed that the membrane system of the trophozoites treated only with dihydroartemisinin for 3.5 h was damaged considerably. The cytoplasm of damaged parasite spilled out. The cytoplasm of the parasite treated only with metronidazole for 3.5-5 h was damaged seriously. Vacuoles and crevices were visible in the cytoplasm. The cell membrane and the content of the parasites treated with the drug mixture for 3.5-4.5 h were damaged seriously. There were some vacuoles and crevices, dilated endoplasmic reticulum, injured and deformed hydrogenosomes in the cytoplasm. The cell organelles mostly disappeared. Crevices also existed in the nucleus. The nuclear membrane fractured and even disappeared.

CONCLUSION

The acting targets of dihydroartemisinin and metronidazole to T. vaginalis trophozoite were different, and a combination of the two drugs shows stronger effect in killing the parasites.

Candimine-induced cell death of the amitochondriate parasite Trichomonas vaginalis

Candimine (1), an alkaloid from the bulbs of Hippeastrum morelianum, was found to be cytotoxic for the amitochondriate parasite Trichomonas vaginalis. Candimine (1) induced cell death with an unprecedented group of effects that failed to fulfill the criteria for apoptosis and apoptosis-like death already reported in trichomonads. Arrest of the parasite cell cycle, and morphologic and ultrastructural alterations, including marked cytoplasmic vacuolization, were induced by 1. The present findings suggest some similarities to paraptotic cell death, described for multicellular organisms. This study contributes to both a better understanding of the biological effects of 1 and T. vaginalis cell biology.