Strategies for Prevention and Treatment of Trichomonas vaginalis Infections

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.

Alpha-Pinene and Tannic Acid Inhibit Trichomonas vaginalis Protozoan Cells by Inducing Apoptosis

Background

Trichomoniasis is one of the most common sexually transmitted infections worldwide. The growing concern of drug resistance of this infection has cautioned the need for new drug development. We evaluated the potential antiproliferative and apoptotic effect of α-pinene and tannic acid (TA) on Trichomonas vaginalis cells. In addition, the cytotoxicity of agents on Vero cells was investigated.

Methods

Trichomonas cells were axenically cultured in TYI-S-33 medium. In vitro antiproliferative activity of α-pinene, TA, and metronidazole was investigated against Trichomonas cells. The assays were carried out in triplicate using microtiter plate and trypan blue staining method. Annexin V/PI staining with flow cytometry was used to evaluate apoptosis induction. In addition, the cytotoxic effect was measured by MTT assay.

Results

α-Pinene and TA exhibited significant inhibition of the Trichomonas cells and the lowest IC50 values were 22.9 μg/ml and 140 μg/ml at 48 hours' incubation, respectively. The CC50 was found at 116 μg/ml for α-pinene and 473 μg/ml for TA, after 48 hours of treatment. The flow cytometry study demonstrated that the natural compounds induced apoptosis in Trichomonas cells. After 24 hours of treatment, the induction of apoptosis was 5.2% - 36.6% at concentrations of 3.9 - 62.5 μg/ml for α-pinene and TA induced-apoptosis was 6.1% - 53.8% at concentrations of 125-2000 μg/ml.

Conclusion

Although the results show the antiproliferative and apoptotic effect of α-pinene and TA on Trichomonas cells, in vivo studies are needed to further clarify the effects of these compounds.

Trichomonas vaginalis adhesion protein 65 (TvAP65) modulates parasite pathogenicity by interacting with host cell proteins

Trichomonas vaginalis (T. vaginalis) is a widespread and important sexually transmitted pathogen. Adherence to the surface of the host cell is the precondition forthis parasite's parasitism and pathogenicity. Adhesion protein 65 (TvAP65) plays a key role in the process of adhesion. However, how TvAP65 mediates the adhesion and pathogenicity of T. vaginalis to host cellsis unclear. In this study, we knocked down the expression of TvAP65 in trophozoites by small RNA interference. The number of T. vaginalis trophozoites adhering to VK2/E6E7 cells was decreased significantly, and the inhibition of VK2/E6E7 cells proliferation and VK2/E6E7 cells apoptosis and death induced by T. vaginalis were reduced, after the expression of TvAP65 was knocked down. Animal challenge experiments showed that the pathogenicity of trophozoites was decreased by passive immunization with anti-rTvAP65 PcAbs or blocking the TvAP65 protein. Immunofluorescence analysis showed that TvAP65 could bind to VK2/E6E7 cells. In order to screen the molecules interacting with TvAP65 on the host cells, we successfully constructed the cDNA library of VK2/E6E7 cells, and thirteen protein molecules interacting with TvAP65 were screened by yeast two-hybrid system. The interaction between TvAP65 and BNIP3 was further confirmed by coimmunoprecipitation and colocalization. When both TvAP65 and BNIP3 were knocked down by small RNA interference, the number of T. vaginalis adhering to VK2/E6E7 cells and the inhibition of VK2/E6E7 cells proliferation were significantly lower than those of the group with knockdown of TvAP65 or BNIP3 alone. Therefore, the interaction of TvAP65 and BNIP3 in the pathogenesis of T. vaginalis infecting host cells is not unique and involves other molecules. Our study elucidated that the interaction between TvAP65 and BNIP3 mediated the adhesion and pathogenicity of T. vaginalis to host cells, provided a basis for searching for the drug targets of anti-T. vaginalis, and afforded new ideas for the prevention and treatment of trichomoniasis.

Vaginal Drug Delivery Systems to Control Microbe-Associated Infections

The vagina has been regarded as a crucial route for drug delivery. Despite the wide range of available vaginal dosage forms for vaginal infection control, poor drug absorptivity remains a significant challenge due to various biological barriers in the vagina, such as mucus, epithelium, immune systems, and others. To overcome these barriers, different types of vaginal drug delivery systems (VDDSs), with outstanding mucoadhesive, mucus-penetrating properties, have been designed to enhance the absorptivity of vagina-administered agents in the past decades. In this Review, we introduce a general understanding of vaginal administration, its biological barriers, the commonly used VDDSs, such as nanoparticles and hydrogels, and their applications in controlling microbe-associated vaginal infections. Additionally, further challenges and concerns regarding the design of VDDSs will be discussed.

Structural elucidation of recombinant Trichomonas vaginalis 20S proteasome bound to covalent inhibitors

Proteasomes are essential for protein homeostasis in mammalian cells1-4 and in protozoan parasites such as Trichomonas vaginalis (Tv).5 Tv and other protozoan 20S proteasomes have been validated as druggable targets.6-8 However, in the case of Tv 20S proteasome (Tv20S), biochemical and structural studies were impeded by low yields and purity of the native proteasome. We successfully made recombinant Tv20S by expressing all seven α and seven β subunits together with the Ump-1 chaperone in insect cells. We isolated recombinant proteasome and showed that it was biochemically indistinguishable from the native enzyme. We confirmed that the recombinant Tv20S is inhibited by the natural product marizomib (MZB)9 and the recently developed peptide inhibitor carmaphycin-17 (CP-17)8,10. Specifically, MZB binds to the β1, β2 and β5 subunits, while CP-17 binds the β2 and β5 subunits. Next, we obtained cryo-EM structures of Tv20S in complex with these covalent inhibitors at 2.8Å resolution. The structures revealed the overall fold of the Tv20S and the binding mode of MZB and CP-17. Our work explains the low specificity of MZB and higher specificity of CP-17 towards Tv20S as compared to human proteasome and provides the platform for the development of Tv20S inhibitors for treatment of trichomoniasis.

The interaction between adhesion protein 33 (TvAP33) and BNIP3 mediates the adhesion and pathogenicity of Trichomonas vaginalis to host cells

BACKGROUND

Trichomonas vaginalis is a widespread and important sexually transmitted pathogen. Adherence to the surface of the host cell is the precondition for the parasitism and pathogenicity of this parasite. Trichomonas vaginalis adhesion protein 33 (TvAP33) plays a key role in the process of adhesion, but how this protein mediates the adhesion and pathogenicity of T. vaginalis to host cells is unclear.

METHODS

The expression of TvAP33 in trophozoites was knocked down by small interfering RNA. VK2/E6E7 cells and mice infected with T. vaginalis were used to evaluate the pathogenicity of T. vaginalis. We constructed a complementary DNA library of VK2/E6E7 cells and screened the protein molecules interacting with TvAP33 by the yeast two-hybrid system. The interaction between TvAP33 and BNIP3 (Bcl-2 interacting protein 3) was analyzed by co-immunoprecipitation and colocalization.

RESULTS

Following knockdown of TvAP33 expression, the number of T. vaginalis trophozoites adhering to VK2/E6E7 cells decreased significantly, and the inhibition of VK2/E6E7 cell proliferation and VK2/E6E7 cell apoptosis and death induced by T. vaginalis were reduced. Animal challenge experiments showed that the pathogenicity of trophozoites decreased following passive immunization with TvAP33 antiserum or blocking of the TvAP33 protein. Immunofluorescence analysis revealed that TvAP33 could bind to VK2/E6E7 cells. Eighteen protein molecules interacting with TvAP33 were identified by the yeast two-hybrid system. The interaction between TvAP33 and BNIP3 was further confirmed by co-immunoprecipitation and colocalization. When the expression of both TvAP33 and BNIP3 in trophozoites was knocked down by small RNA interference, the number of T. vaginalis adhering to VK2/E6E7 cells and the inhibition of VK2/E6E7 cell proliferation were significantly lower compared to trophozoites with only knockdown of TvAP33 or only BNIP3. Therefore, the interaction of TvAP33 and BNIP3 in the pathogenesis of T. vaginalis infecting host cells is not unique and involves other molecules.

CONCLUSIONS

Our study showed that the interaction between TvAP33 and BNIP3 mediated the adhesion and pathogenicity of T. vaginalis to host cells, providing a basis for searching for drug targets for T. vaginalis as well as new ideas for the prevention and treatment of trichomoniasis.

Metallic Nanoparticles and Core-Shell Nanosystems in the Treatment, Diagnosis, and Prevention of Parasitic Diseases

The usage of nanotechnology in the fight against parasitic diseases is in the early stages of development, but it brings hopes that this new field will provide a solution to target the early stages of parasitosis, compensate for the lack of vaccines for most parasitic diseases, and also provide new treatment options for diseases in which parasites show increased resistance to current drugs. The huge physicochemical diversity of nanomaterials developed so far, mainly for antibacterial and anti-cancer therapies, requires additional studies to determine their antiparasitic potential. When designing metallic nanoparticles (MeNPs) and specific nanosystems, such as complexes of MeNPs, with the shell of attached drugs, several physicochemical properties need to be considered. The most important are: size, shape, surface charge, type of surfactants that control their dispersion, and shell molecules that should assure specific molecular interaction with targeted molecules of parasites' cells. Therefore, it can be expected that the development of antiparasitic drugs using strategies provided by nanotechnology and the use of nanomaterials for diagnostic purposes will soon provide new and effective methods of antiparasitic therapy and effective diagnostic tools that will improve the prevention and reduce the morbidity and mortality caused by these diseases.

Transcriptional profile of Trichomonas vaginalis in response to metronidazole

BACKGROUND

Trichomoniasis caused by Trichomonas vaginalis, combined with its complications, has long frequently damaged millions of human health. Metronidazole (MTZ) is the first choice for therapy. Therefore, a better understanding of its trichomonacidal process to ultimately reveal the global mechanism of action is indispensable. To take a step toward this goal, electron microscopy and RNA sequencing were performed to fully reveal the early changes in T. vaginalis at the cellular and transcriptome levels after treatment with MTZ in vitro.

RESULTS

The results showed that the morphology and subcellular structures of T. vaginalis underwent prominent alterations, characterized by a rough surface with bubbly protrusions, broken holes and deformed nuclei with decreased nuclear membranes, chromatin and organelles. The RNA-seq data revealed a total of 10,937 differentially expressed genes (DEGs), consisting of 4,978 upregulated and 5,959 downregulated genes. Most DEGs for the known MTZ activators, such as pyruvate:ferredoxin oxidoreductase (PFOR) and iron-sulfur binding domain, were significantly downregulated. However, genes for other possible alternative MTZ activators such as thioredoxin reductase, nitroreductase family proteins and flavodoxin-like fold family proteins, were dramatically stimulated. GO and KEGG analyses revealed that genes for basic vital activities, proteostasis, replication and repair were stimulated under MTZ stress, but those for DNA synthesis, more complicated life activities such as the cell cycle, motility, signaling and even virulence were significantly inhibited in T. vaginalis. Meanwhile, increased single nucleotide polymorphism (SNP) and insertions - deletions (indels) were stimulated by MTZ.

CONCLUSIONS

The current study reveals evident nuclear and cytomembrane damage and multiple variations in T. vaginalis at the transcriptional level. These data will offer a meaningful foundation for a deeper understanding of the MTZ trichomonacidal process and the transcriptional response of T. vaginalis to MTZ-induced stress or even cell death.

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.

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.

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

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

Prevalence 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.

Development and validation of a predictive model for the risk of developing trichomonas vaginitis in women

Trichomonas vaginitis (TV) is the most common non-viral sexually transmitted infection (STI) worldwide. The high prevalence of TV combined with mild or asymptomatic early symptoms leads to clinical vulnerability from delayed diagnosis. Latent infection can increase the incidence of pelvic infections, infertility, and adverse pregnancy complications. Data from 898 women who underwent vaginal flora testing from June 2014 to December 2014 were used to create a nomogram to assess the risk of TV in women in order to guide TV prevention and clinical intervention. The prediction model was evaluated in terms of identification, calibration, and clinical utility using the C-index, calibration plots, decision curve analysis, and internal validation. Predictors in the TV nomogram included age, occupation, yearly income, tea drinking, bathing frequency, menopause, spontaneous abortion, use of contraceptives, history of gynecological surgery, and HPV infection. The C-index of the TV risk prediction model was 0.732 (95% confidence interval: 0.695-0.768). It showed good discriminatory and predictive power. Decision curve analysis indicated that the nomogram had a good net benefit when the threshold probability of TV in women was 2-80%. The established TV prediction model easily, accurately, and quickly predicts the risk of TV onset.

Locust Bean Gum Nano-Based Hydrogel for Vaginal Delivery of Diphenyl Diselenide in the Treatment of Trichomoniasis: Formulation Characterization and In Vitro Biological Evaluation

Trichomoniasis is the most common nonviral sexually transmitted infection in the world, but its available therapies present low efficacy and high toxicity. Diphenyl diselenide (PhSe₂) is a pharmacologically active organic selenium compound; however, its clinical use is hindered by its lipophilicity and toxicity. Nanocarriers are an interesting approach to overcome the limitations associated with this compound. This study designed and evaluated a vaginal hydrogel containing PhSe₂-loaded Eudragit^® RS100 and coconut oil nanocapsules for the treatment of trichomoniasis. Nanocapsules presented particle sizes in the nanometric range, positive zeta potential, a compound content close to the theoretical value, and high encapsulation efficiency. The nanoencapsulation maintained the anti-Trichomonas vaginalis action of the compound while improving the scavenger action in a DPPH assay. The hydrogels were prepared by thickening nanocapsule suspensions with locust bean gum (3%). The semisolids maintained the nanometric size of the particles and the PhSe₂ content at around the initial concentration (1.0 mg/g). They also displayed non-Newtonian pseudo-plastic behavior and a highly mucoadhesive property. The chorioallantoic membrane method indicated the absence of hemorrhage, coagulation, or lysis. The compound, from both non-encapsulated and nano-based hydrogel delivery systems, remained on the surface of the bovine vaginal mucosa. Therefore, the formulations displayed the intended properties and could be a promising alternative for the treatment of trichomoniasis.

Mass Spectrometry Metabolomics Approach Reveals Anti-Trichomonas vaginalis Scaffolds from Marine Fungi

Trichomoniasis is the most common non-viral sexually transmitted infection (STI) in the world caused by Trichomonas vaginalis. Failures in the treatment with the 5-nitroimidazole class including parasite resistance to metronidazole elicit new alternatives. Marine natural products are sources of several relevant molecules, presenting a variety of metabolites with numerous biological activities. In this work, we evaluated the anti-T. vaginalis activity of fungi associated with marine invertebrates by mass spectrometry-based metabolomics approaches. After screening of six marine fungi, extract from Penicillium citrinum FMPV 15 has shown to be 100% active against T. vaginalis, and the gel permeation column on Sephadex LH-20® yielded twelve organic fractions which five showed to be active. Metabolomics and statistical analyses were performed with all the samples (extract and fractions), and several compounds were suggested to be related to the activity. These components include citrinin, dicitrinin C, citreoisocoumarin, dihydrocitrinone, decarboxycitrinin, penicitrinone C, and others. The minimum inhibitory concentration (MIC) value of anti-T. vaginalis activity of citrinin was 200 µM. The marine fungi metabolites show potential as new alternatives to overcome drug resistance in T. vaginalis infections.

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.

Metronidazole-loaded nanoparticulate thermoreversible gel for gynecologic infection of Trichomonas vaginalis

OBJECTIVE

Trichomoniasis is a common sexually-transmitted disease that is associated with increased perinatal morbidity and human immunodeficiency virus (HIV) transmission. This study aimed to develop a Metronidazole-loaded nanoparticulate thermoreversible gel for gynecological infection of Trichomonas vaginalis (T. vaginalis).

METHODS

The optimized nanoparticulate formulation was used in thermoreversible gel and characterized for physico-chemical properties, antiparasitic activity, and in vivo efficacy in the BALB/c mouse model.

RESULT

A nearly threefold rise in antiparasitic activity of the optimized formulation was observed as compared to that of regular gel. Formulation F5 successfully cured the trichomoniasis within 3 days, while regular gel and pure Metronidazole (MTDZ) failed to cure this infection (P<0.05).

CONCLUSION

The present investigation confirms the ability of thermoreversible gel containing nanoparticulate metronidazole againstthe infection by T. vaginalis. The developed gel could be an alternative to the existing drug delivery system for the treatment of trichomoniasis.

Detection of metronidazole resistance in Trichomonas vaginalis using uncultured vaginal swabs

Trichomonas vaginalis (T. vaginalis) is the most prevalent sexually transmitted infection (STI) globally. Metronidazole is the drug of choice for treating T. vaginalis infections although metronidazole-resistant T. vaginalis has been reported in clinical isolates. The purpose of this study was to determine the presence of mutations in nitroreductase genes associated with metronidazole resistance in vaginal swabs testing positive for T. vaginalis. This study included 385 human immunodeficiency virus (HIV)-positive pregnant women. Vaginal swabs were collected from consenting pregnant women and used for the detection of T. vaginalis using the TaqMan assay. From the vaginal swabs, nitroreductase genes ntr4 and ntr6 containing mutations associated with metronidazole resistance were amplified using a quantitative polymerase chain reaction (PCR) assay. To validate the PCR assay, T. vaginalis cultured isolates with known metronidazole resistance profiles were used as controls in the mutation detection assays. The prevalence of T. vaginalis in the study population was 12.2% (47/385). Mutations associated with resistance to metronidazole were detected in more than 40% of the samples tested, i.e. 21/47 (45%) and 24/47 (51%) for ntr4 and ntr6, respectively. A total of 19 samples (40%) carried mutations for both ntr4 and ntr6 genes associated with metronidazole resistance. The validation assays showed a positive correlation between phenotypic and genotypic resistance profiles. This study found a high prevalence of mutations associated with metronidazole resistance. This is concerning since metronidazole is currently used in the syndromic management of STIs in South Africa. Molecular-based assays for monitoring metronidazole resistance profiles using nitroreductase genes may serve as a feasible method for antimicrobial surveillance studies for T. vaginalis.

CYT387, a JAK-Specific Inhibitor Impedes Osteoclast Activity and Oophorectomy-Induced Osteoporosis via Modulating RANKL and ROS Signaling Pathways

Osteoclasts are of hematopoietic lineage and have the ability to degrade mineralized bone tissues. Abnormalities in osteoclastic activity under certain pathological conditions are common in bone diseases such as osteoporosis, osteosclerosis, and arthritis. Although many kinds of drugs are currently used to treat osteoporosis, they have obvious adverse reactions and limitations. CYT387 is a new small-molecule Janus kinase (JAK) inhibitor involved in hematopoiesis, immune modulation, fertility, lactation, and embryonic development. However, it has remained unclear whether CYT387 functionally impacts osteoclast formation. Our study demonstrated through osteoclast formation assay in vitro, that the use of CYT387 is a potential drug candidate for treating osteoclast-associated bone disease. The effects of CYT387 on osteoclast formation, bone resorption, NFATc1 activation, and especially intracellular ROS levels were investigated in vitro. Further, we examined the preclinical prospects of CYT387 using an oophorectomy (OVX) mouse model of osteoporosis with its anti-osteoclast activity in vivo. On the whole, this study shows that CYT387 holds promise for treating osteoclast-related bone illnesses including osteoporosis.

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

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

Kinetic and Molecular Docking Studies to Determine the Effect of Inhibitors on the Activity and Structure of Fused G6PD::6PGL Protein from Trichomonas vaginalis

Trichomoniasis is a sexually transmitted disease with a high incidence worldwide, affecting 270 million people. Despite the existence of a catalog of available drugs to combat this infection, their extensive use promotes the appearance of resistant Trichomonas vaginalis (T. vaginalis), and some side effects in treated people, which are reasons why it is necessary to find new alternatives to combat this infection. In this study, we investigated the impact of an in-house library comprising 55 compounds on the activity of the fused T. vaginalis G6PD::6PGL (TvG6PD::6PGL) protein, a protein mediating the first reaction step of the pentose phosphate pathway (PPP), a crucial pathway involved in the parasite's energy production. We found four compounds: JMM-3, CNZ-3, CNZ-17, and MCC-7, which inhibited the TvG6PD::6PGL protein by more than 50%. Furthermore, we determined the IC₅₀, the inactivation constants, and the type of inhibition. Our results showed that these inhibitors induced catalytic function loss of the TvG6PD::6PGL enzyme by altering its secondary and tertiary structures. Finally, molecular docking was performed for the best inhibitors, JMM-3 and MCC-7. All our findings demonstrate the potential role of these selected hit compounds as TvG6PD::6PGL enzyme selective inhibitors.

Prevalence and spatial heterogeneity of Trichomonas vaginalis infection among the female population and association with climate in Guangxi Zhuang autonomous region, Southern China

BACKGROUND

Two cervical cancer screening (CCS) projects have been ongoing for years in Guangxi Zhuang autonomous region (Guangxi), and some Trichomonas vaginalis infection (TVI) cases have been found as an opportunistic finding. This study aimed to identify the high-risk population and expound the spatial epidemiological features of TVI in Guangxi.

METHODS

This study was based on CCS from 2012 to 2019. Adjusted odds ratio (AOR), and spatial analyses were used to identify the high-risk subgroups, as well as to depict the spatial epidemiological feature and its relationship with meteorological factors.

RESULTS

The infection rate of TVI was 0.38% in 873,880 samples. Significant association with a high risk of TVI was found in the following: females aged 40-49 years (aOR=4.464; 95% CI, 3.359-5.932; p<0.001), aged 50-59 years (aOR=3.169; 95% CI, 2.370-4.237; p<0.001), from urban (aOR=1.577; 95% CI, 1.471-1.691; p<0.001), from minority areas (aOR=1.183; 95% CI, 1.060-1.320; p=0.003), areas with GPD <41,500 CNY (aOR=1.191; 95% CI, 1.106-1.282; p<0.001), and inland areas (aOR=1.520; 95% CI, 1.339-1.726; p<0.001). Counties with higher infection rate were concentrated in northwest Guangxi's mountainous area (Z-score=3.9656, p<0.001), in the upper reaches of the Hongshui River and Yu River, and with a significant spatial autocorrelation (Moran's I=0.581, p=0.002). Spatial error model showed significantly negative regressions among temperature (B=-0.295, p=0.002), annual temperature range (B=-0.295, p=0.002), and TVI spatial distribution.

CONCLUSION

The spatial clustering and disparity of TVI in northwest Guangxi warrant further study, and meteorological conditions may play an important role in TVI in northwest Guangxi.

Lupeol acetate isolated from Chrysophyllum cainito L. fruit as a template for the synthesis of N-alkyl-arylsulfonamide derivatives and their synergistic effects with metronidazole against Trichomonas vaginalis

Pentacyclic triterpenes are found in a great variety of natural products and constitute an organic template for the development of new derivative compounds with therapeutic applications. In the present work, lupeol acetate isolated from Chrysophyllum cainito L. fruit was used as a template for the synthesis of novel N-alkyl-arylsulfonamide derivatives, and their synergistic effects with metronidazole against strains of Trichomonas vaginalis were tested. A library of 18 derivatives was synthesized. Ten compounds exhibited an IC₅₀ < 100 μM against a metronidazole-sensitive strain of T. vaginalis. Only seven of these compounds (12, 15, 18-22) also showed activity against metronidazole-resistant strains. The compounds 20 (N-cyclohexyl-p-chlorobenzenesulfonamidolupeol acetate) and 22 (N-cyclohexyl-p-nitrobenzenesulfonamidolupeol acetate) exhibited a similar IC₅₀ against both susceptible and resistant T. vaginalis strains and enhanced the efficacy of metronidazole in a partial and total synergistic way, respectively. These data provided evidence of the trichomonicidal effect of N-alkyl-arylsulfonamide derivatives of lupeol acetate, representing highly promising novel antiparasitic agents.

Antiparasitic Effects of Sulfated Polysaccharides from Marine Hydrobionts

This review presents materials characterizing sulfated polysaccharides (SPS) of marine hydrobionts (algae and invertebrates) as potential means for the prevention and treatment of protozoa and helminthiasis. The authors have summarized the literature on the pathogenetic targets of protozoa on the host cells and on the antiparasitic potential of polysaccharides from red, brown and green algae as well as certain marine invertebrates. Information about the mechanisms of action of these unique compounds in diseases caused by protozoa has also been summarized. SPS is distinguished by high antiparasitic activity, good solubility and an almost complete absence of toxicity. In the long term, this allows for the consideration of these compounds as effective and attractive candidates on which to base drugs, biologically active food additives and functional food products with antiparasitic activity.

Vaginal pH Value for Clinical Diagnosis and Treatment of Common Vaginitis

In modern society, 75% of all women worldwide have had vaginitis at least once in their lives. The vagina has a dynamic microbial ecosystem with varying vaginal pH levels. An imbalance in that ecosystem can alter the vaginal pH and tip the scale to the point of causing issues, such as vaginitis, that require medical attention. Although vaginitis is not an incurable disease, it causes discomfort and pain that disrupt women's daily lives. The most common causes of vaginitis include bacterial vaginosis, trichomoniasis, and vulvovaginal candidiasis. In this review, we discuss the causes, diagnostic methods, and symptoms of different types of vaginitis, the relationship of vaginitis to the prevalence of other diseases, issues associated with recurrent vaginitis and the immune system, and a variety of effective available treatments. In our article, we summarize the relationship of pH with the vaginal ecosystem, discuss the associated factors of vaginal pH, and finally introduce the different available vaginal pH self-test products.

A review on Trichomonas vaginalis infections in women from Africa

Background

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

Aim

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

Method

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

Results

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

Conclusion

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

A reassessment of the role of oxygen scavenging enzymes in the emergence of metronidazole resistance in trichomonads

Trichomonads are an order of parasitic protists which infect a wide range of hosts. The human parasite Trichomonas vaginalis and the bovine parasite Tritrichomonas foetus which also infects cats and swine are of considerable medical and veterinary importance, respectively. Since trichomonads are microaerophiles/anaerobes they are susceptible to 5-nitroimidazoles such as metronidazole. 5-nitroimidazoles are exclusively toxic to microaerophilic/anaerobic organisms because reduction, i.e. activation, of the drug can only occur in a highly reductive environment. 5-nitroimidazoles have remained a reliable treatment option throughout the last decades but drug resistance can be a problem. Clinical resistance to 5-nitroimidazoles has been studied in more detail in T. vaginalis and has been ascribed to defective oxygen scavenging mechanisms which lead to higher intracellular oxygen concentrations and, consequently, to less drug being reduced. Two enzymes, flavin reductase (FR) and NADH oxidase have been suggested to be the major oxygen scavenging enzymes in T. vaginalis. The loss, or at least an impairment of FR which reduces oxygen to hydrogen peroxide, has been proposed as the central mechanism that enables the emergence of 5-nitroimidazole resistance. In this study we explored if T. foetus also encodes a homolog of FR and if it is, likewise, involved in resistance. T. foetus was indeed found to express a FR but it was only weakly active as compared to the T. vaginalis homolog. Further, activity of FR in T. foetus was unchanged in metronidazole-resistant cell lines, ruling out that it has a role in metronidazole resistance. Finally, we measured oxygen scavenging rates in metronidazole-sensitive and -resistant cell lines and found that NADH oxidase and FR are not the major oxygen scavenging enzymes in trichomonads and that oxygen scavenging is possibly a consequence, rather than a cause of metronidazole resistance.

Global prevalence of Trichomonas vaginalis among female sex workers: a systematic review and meta-analysis

Trichomoniasis is a sexually transmitted infection (STI), caused by the protozoan parasite, Trichomonas vaginalis. Female sex workers are intensely affected by the infection, since they have frequent direct physical contact. The current systematic review and meta-analysis represents the global prevalence of T. vaginalis in female sex workers. Five databases (Science Direct, Scopus, PubMed, Web of Science, and Google Scholar) were explored for literatures that published from July 1985 to June 2020. Totally, 85 studies (54,515 participants) from 46 countries met the inclusion criteria. The global pooled prevalence of T. vaginalis was 16% (95% CI 13-19%). The estimated pooled prevalence based on methods including wet mount, culture, and molecular techniques was 15% (95% CI 12-19%), 16% (95% CI 10-24%), and 22% (95% CI 13-32%), respectively. Moreover, the infection was most prevalent at the mean age of 30-36 (20%, 95% CI 11-30%). Regarding the World Health Organization (WHO) regions, the highest pooled prevalence was estimated to be in the African region (23%, 95% CI 7-46%). In addition, we indicated that countries with low-income level have the highest pooled prevalence (23%, 95% CI 14-34%). Our results revealed that the worldwide prevalence of T. vaginalis was significant in female sex workers. Therefore, considering a precise strategy such as a health education program with regard to safe intercourse is needed to increase knowledge and prevent T. vaginalis infection in sex workers.

Deazapurine Nucleoside Analogues for the Treatment of Trichomonas vaginalis

Trichomoniasis is the most common nonviral sexually transmitted disease in humans, but treatment options are limited. Here, we report a resorufin-based drug sensitivity assay for high-throughput microplate-based screening under hypoxic conditions. A 5203-compound enamine kinase library and several specialized compound series were tested for the inhibition of Trichomonas growth at 10 μM with Z' values of >0.5. Hits were rescreened in serial dilution to establish an IC₅₀ concentration. A series of 7-substituted 7-deazaadenosine analogues emerged as highly potent anti-T. vaginalis agents, with EC₅₀ values in the low double digit nanomolar range. These analogues exhibited excellent selectivity indices. Follow-up medicinal chemistry efforts identified an optimal ribofuranose and C7 substituent. Several nucleosides rapidly cleared cultures of T. vaginalis at a concentrations of just 2 × EC₅₀. Preliminary in vivo evaluation in a murine trichomoniasis model (Tritrichomonas foetus) revealed promising activity upon topical administration, validating purine nucleoside analogues as a new class of antitrichomonal agents.

Distribution of genotypes in relation to metronidazole susceptibility patterns in Trichomonas vaginalis isolated from South African pregnant women

Reports on metronidazole resistance of Trichomonas vaginalis strains have been on the increase. This study investigated the in vitro metronidazole resistance patterns in T. vaginalis isolates obtained from South African pregnant women and the genotypes of these isolates. This study included 362 pregnant women recruited from a hospital in Durban, South Africa. The women provided self-collected vaginal swabs for the detection of T. vaginalis by culture in Diamonds media. Cultured isolates were then subjected to anaerobic susceptibility assays to metronidazole. For the genotyping assays, the actin gene was digested by HindII, MseI, and RsaI. The banding patterns obtained after digestion was used to determine the genotypes. A total of 21/362 (5.8%) pregnant women tested positive for T. vaginalis infection. Of the 21 T. vaginalis isolates tested for metronidazole susceptibility, 9.5% (2/21) had a minimum inhibitory concentration (MIC) of 4 μg/ml (resistant), 38.1% (8/21) had a MIC of 2 μg/ml (intermediate), and 52.4% (11/21) had a MIC ≤ 1 μg/ml (susceptible). The dominant genotype that was identified across the isolates was genotype G. There was no correlation between genotype harboured and metronidazole susceptibility patterns. In this study, resistance to metronidazole was observed in clinical isolates of T. vaginalis. This study did not find a correlation between genotype harboured and metronidazole susceptibility patterns. Despite the lack of association, our study provides data on an area of research that is currently lacking in our setting.

Trichomonas vaginalis infection impairs anion secretion in vaginal epithelium

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

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

TriTOX: A novel Trichomonas vaginalis assay platform for high-throughput screening of compound libraries

Trichomonas vaginalis is a neglected urogenital parasitic protist that causes 170 million cases of trichomoniasis annually, making it the most prevalent non-viral, sexually transmitted disease. Trichomoniasis treatment relies on nitroheterocyclics, such as metronidazole. However, with increasing drug-resistance, there is an urgent need for novel anti-trichomonals. Little progress has been made to translate anti-trichomonal research into commercialised therapeutics, and the absence of a standardised compound-screening platform is the immediate stumbling block for drug-discovery. Herein, we describe a simple, cost-effective growth assay for T. vaginalis and the related Tritrichomonas foetus. Tracking changes in pH were a valid indicator of trichomonad growth (T. vaginalis and T. foetus), allowing development of a miniaturised, chromogenic growth assay based on the phenol red indicator in 96- and 384-well microtiter plate formats. The outputs of this assay can be quantitatively and qualitatively assessed, with consistent dynamic ranges based on Z' values of 0.741 and 0.870 across medium- and high-throughput formats, respectively. We applied this high-throughput format within the largest pure-compound microbial metabolite screen (812 compounds) for T. vaginalis and identified 43 hit compounds. We compared these identified compounds to mammalian cell lines, and highlighted extensive overlaps between anti-trichomonal and anti-tumour activity. Lastly, observing nanomolar inhibition of T. vaginalis by fumagillin, and noting this compound has reported activity in other protists, we performed in silico analyses of the interaction of fumagillin with its molecular target methionine aminopeptidase 2 for T. vaginalis, Giardia lamblia and Entamoeba histolytica, highlighting potential for fumagillin as a broad-spectrum anti-protistal against microaerophilic protists. Together, this new platform will accelerate drug-discovery efforts, underpin drug-resistance screening in trichomonads, and contributing to a growing body of evidence highlighting the potential of microbial natural products as novel anti-protistals.

Recent Advances in Nanosystems and Strategies for Vaginal Delivery of Antimicrobials

Vaginal infections such as bacterial vaginosis (BV), chlamydia, gonorrhea, genital herpes, candidiasis, and trichomoniasis affect millions of women each year. They are caused by an overgrowth of microorganisms, generally sexually transmitted, which in turn can be favored by alterations in the vaginal flora. Conventional treatments of these infections consist in systemic or local antimicrobial therapies. However, in the attempt to reduce adverse effects and to contrast microbial resistance and infection recurrences, many efforts have been devoted to the development of vaginal systems for the local delivery of antimicrobials. Several topical dosage forms such as aerosols, lotions, suppositories, tablets, gels, and creams have been proposed, although they are sometimes ineffective due to their poor penetration and rapid removal from the vaginal canal. For these reasons, the development of innovative drug delivery systems, able to remain in situ and release active agents for a prolonged period, is becoming more and more important. Among all, nanosystems such as liposomes, nanoparticles (NPs), and micelles with tunable surface properties, but also thermogelling nanocomposites, could be exploited to improve local drug delivery, biodistribution, retention, and uptake in vulvovaginal tissues. The aim of this review is to provide a survey of the variety of nanoplatforms developed for the vaginal delivery of antimicrobial agents. A concise summary of the most common vaginal infections and of the conventional therapies is also provided.

Anti-Trichomonas vaginalis Effect of Methanolic Extracts of Sambucus nigra in Comparison with Metronidazole

Background: Trichomoniasis is the most common non-viral sexually transmitted disease caused by a flagellated protozoan living in the genitourinary tract, which infects both men and women. Metronidazole is the treatment of choice for trichomoniasis. Researchers are seeking an alternative to metronidazole because of its inevitable side effects and toxicity. Objectives: This study aimed to evaluate the effect of the methanolic extract of Sambucus nigra against Trichomonas vaginalis in vitro. Methods: Plants were collected from different areas of Mazandaran Province, northern Iran. Fruits were separated, shade-dried, milled, and their methanolic extract was prepared in concentrations of 100, 200, 400, and 800 µg/mL. Parasites were obtained from patients referring to different health centers of Mazandaran province, cultured in Dorset medium, and incubated at 37°C. The effects were evaluated and compared to a control group. The data were analyzed by SPSS 18 using the ANOVA test. Results: The exposure time and concentration of the extracts had a direct effect on anti-parasitic activity so that increasing extract concentration and incubation time heightened the anti-trichomoniasis effects. The concentrations of 400 and 800 µg/ml of the plant had 100% efficacy after 72 and 48 hours, respectively. Conclusions: It can be concluded from our results that the methanolic extract of S. nigra has a remarkable ability to destroy T. vaginalis and it can be considered an effective drug against T. vaginalis with further studies in human and animal models.

Adherence of Trichomonas vaginalis to SiHa Cells is Inhibited by Diphenyleneiodonium

Microbial adhesion is critical for parasitic infection and colonization of host cells. To study the host–parasite interaction in vitro, we established a flow cytometry-based assay to measure the adherence of Trichomonas vaginalis to epithelial cell line SiHa. SiHa cells and T. vaginalis were detected as clearly separated, quantifiable populations by flow cytometry. We found that T. vaginalis attached to SiHa cells as early as 30 min after infection and the binding remained stable up to several hours, allowing for analysis of drug treatment efficacy. Importantly, NADPH oxidase inhibitor DPI treatment induced the detachment of T. vaginalis from SiHa cells in a dose-dependent manner without affecting host cell viability. Thus, this study may provide an understanding for the potential development of therapies against T. vaginalis and other parasite infections.

Anti-trichomonad activities of different compounds from foods, marine products, and medicinal plants: a review

Human trichomoniasis, caused by the pathogenic parasitic protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease that contributes to reproductive morbidity in affected women and possibly to prostate cancer in men. Tritrichomonas foetus strains cause the disease trichomoniasis in farm animals (cattle, bulls, pigs) and diarrhea in domestic animals (cats and dogs). Because some T. vaginalis strains have become resistant to the widely used drug metronidazole, there is a need to develop alternative treatments, based on safe natural products that have the potential to replace and/or enhance the activity of lower doses of metronidazole. To help meet this need, this overview collates and interprets worldwide reported studies on the efficacy of structurally different classes of food, marine, and medicinal plant extracts and some of their bioactive pure compounds against T. vaginalis and T. foetus in vitro and in infected mice and women. Active food extracts include potato peels and their glycoalkaloids α-chaconine and α-solanine, caffeic and chlorogenic acids, and quercetin; the tomato glycoalkaloid α-tomatine; theaflavin-rich black tea extracts and bioactive theaflavins; plant essential oils and their compounds (+)-α-bisabolol and eugenol; the grape skin compound resveratrol; the kidney bean lectin, marine extracts from algae, seaweeds, and fungi and compounds that are derived from fungi; medicinal extracts and about 30 isolated pure compounds. Also covered are the inactivation of drug-resistant T. vaginalis and T. foetus strains by sensitized light; anti-trichomonad effects in mice and women; beneficial effects of probiotics in women; and mechanisms that govern cell death. The summarized findings will hopefully stimulate additional research, including molecular-mechanism-guided inactivations and human clinical studies, that will help ameliorate adverse effects of pathogenic protozoa.

A systematic review of the literature on mechanisms of 5-nitroimidazole resistance in Trichomonas vaginalis

BACKGROUND

Trichomonas vaginalis is the most common non-viral sexually transmitted infection. 5-Nitroimidazoles [metronidazole (MTZ) and tinidazole (TDZ)] are FDA-approved treatments. To better understand treatment failure, we conducted a systematic review on mechanisms of 5-nitroimidazole resistance.

METHODS

PubMed, ScienceDirect and EMBASE databases were searched using keywords Trichomonas vaginalis, trichomoniasis, 5-nitroimidazole, metronidazole, tinidazole and drug resistance. Non-English language articles and articles on other treatments were excluded.

RESULTS

The search yielded 606 articles, of which 550 were excluded, leaving 58 articles. Trichomonas vaginalis resistance varies and is higher with MTZ (2.2-9.6%) than TDZ (0-2%). Resistance can be aerobic or anaerobic and is relative rather than absolute. Differential expression of enzymes involved in trichomonad energy production and antioxidant defenses affects 5-nitroimidazole drug activation; reduced expression of pyruvate:ferredoxin oxidoreductase, ferredoxin, nitroreductase, hydrogenase, thioredoxin reductase and flavin reductase are implicated in drug resistance. Trichomonas vaginalis infection with Mycoplasma hominis or T. vaginalis virus has also been associated with resistance. Trichomonas vaginalis has two genotypes, with greater resistance seen in type 2 (vs type 1) populations.

DISCUSSION

5-Nitroimidazole resistance results from differential expression of enzymes involved in energy production or antioxidant defenses, along with genetic mutations in the T. vaginalis genome. Alternative treatments outside of the 5-nitroimidazole class are needed.

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

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

Phytochemical Compositions and Biological Activities of Essential Oils from the Leaves, Rhizomes and Whole Plant of Hornstedtia bella Škorničk

The rapid emergence of drug-resistant strains and novel viruses have motivated the search for new anti-infectious agents. In this study, the chemical compositions and cytotoxicity, as well as the antibacterial, antifungal, antitrichomonas, and antiviral activities of essential oils from the leaves, rhizomes, and whole plant of Hornstedtia bella were investigated. The GC/MS analysis showed that β-pinene, E-β-caryophyllene, and α-humulene were found at high concentrations in the essential oils. The essential oils exhibited (i) inhibition against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis with minimum inhibitory concentrations (MIC) and minimum lethal concentration (MLC) values from 1 to 4% (v/v); (ii) MIC and MLC values from 2 to 16% (v/v) in Candida tropicalis and Candida parapsilosis; (iii) MIC and MLC values from 4 to 16% in Enterococcus faecalis; and (iv) MIC and MLC values from 8 to greater than or equal to 16% (v/v) in the remaining strains, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Candida albicans, and Candida glabrata. In antitrichomonas activity, the leaves and whole-plant oils of Hornstedtia bella possessed IC₅₀, IC₉₀, and MLC values of 0.008%, 0.016%, and 0.03% (v/v), respectively, whilst those of rhizomes oil had in turn, 0.004%, 0.008%, and 0.016% (v/v).Besides, the leaf oil showed a weak cytotoxicity against Vero 76 and MRC-5; meanwhile, rhizomes and whole-plant oils did not exert any toxic effects on cell monolayers. Finally, these oils were not active against EV-A71.

Molecular epidemiology and socio-demographic risk factors of sexually transmitted infections among women in Lebanon

BACKGROUND

Sexually transmitted infections (STIs) cause a major public health problem that affect both men and women in developing and developed countries. The aim of the study was to estimate the prevalence of 11 STIs among women who voluntarily participated in the study, while seeking gynecological checkup. The existence of an association between the presence of pathogens and symptoms and various sociodemographic risk factors was assessed.

METHODS

A total of 505 vaginal and cervical specimens were collected from women above 18 years of age, with or without symptoms related to gynecological infections. Nucleic acid was extracted and samples were tested by real-time PCR for the following pathogens: Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, Ureaplasma urealyticum, Urealplasma parvum, Trichomonas vaginalis, Mycoplasma hominis, Mycoplasma girerdii, Gardnerella vaginalis, Candida albicans and Human Papillomavirus (HPV). Positive HPV samples underwent genotyping using a microarray system.

RESULTS

Of the 505 samples, 312 (62%) were screened positive for at least one pathogen. Of these, 36% were positive for Gardnerella vaginalis, 35% for Ureaplasma parvum, 8% for Candida albicans, 6.7% for HPV, 4.6% for Ureaplasma urealyticum, 3.6% for Mycoplasma hominis, 2% for Trichomonas vaginalis, 0.8% for Chlamydia trachomatis, 0.4% for Mycoplasma girerdii, 0.2% for Mycoplasma genitalium and 0.2% for Neisseria gonorrhoeae. Lack of symptoms was reported in 187 women (37%), among whom 61% were infected. Thirty-four samples were HPV positive, with 17 high risk HPV genotypes (HR-HPV); the highest rates being recorded for types 16 (38%), 18 (21%) and 51 (18%). Out of the 34 HPV positives, 29 participants had HR-HPV. Association with various risk factors were reported.

CONCLUSIONS

This is the first study that presents data about the presence of STIs among women in Lebanon and the MENA region by simultaneous detection of 11 pathogens. In the absence of systematic STI surveillance in Lebanon, concurrent screening for HPV and PAP smear is warranted.

Prevalence of Trichomonas vaginalis Infection Among US Males, 2013-2016

Background

Trichomoniasis results from adhesion of Trichomonas vaginalis to the mucous membrane of the urethra or vagina. It has been estimated to have a higher incidence rate than both gonorrhea and chlamydia combined. Although females can experience both clinical symptoms and obstetrical complications, male infections are largely asymptomatic and often unreported. We aim to estimate the prevalence of trichomoniasis in US males using the National Health and Nutrition Examination Survey (NHANES) database.

Methods

The NHANES database was queried for all men aged 18-59 years during the years 2013-2016. During these years, the survey included urine testing for trichomoniasis using transcription-mediated amplification. Information was also obtained regarding patient demographics and other sexually transmitted infections.

Results

Overall, 0.49% of men aged 18-59 years tested positive for trichomoniasis. The highest rate was seen in black men (3.6%). There was no significant association with trichomoniasis and age. Higher rates of infection were seen in smokers, those with herpes simplex virus type 2 (HSV-2) infection, men who had sex at an early age, those with less condom usage, and those with more lifetime sexual partners.

Conclusion

The rates of trichomonas infection in US males are lower than in women. Infections are strongly associated with black males, HSV-2 infection, and other factors known to increase rates of sexually transmitted infection. This information may be helpful for counseling, screening, and management of patients.

Prevalence and risk factors for Trichomonas vaginalis infection in pregnant women in South Africa

There are insufficient data on the prevalence of Trichomonas vaginalis infection in pregnant women in South Africa. The present study aims to determine the prevalence of T. vaginalis (TV) in pregnant women and identify the risk factors associated with this infection in pregnancy. This was a cross-sectional study which included 362 pregnant women attending the antenatal clinic at the King Edward VIII Hospital in Durban, South Africa. A self-collected vaginal swab was provided by the enrolled women for laboratory diagnosis by real-time polymerase chain reaction. The protozoan load was determined as the logarithm of gene copies per milliliter. The prevalence of TV infection was 12.9% and 59.6% of the women who tested positive were asymptomatic ( p =  0.011). Women who presented with abnormal vaginal discharge had a 4.6 times likelihood of testing positive for TV infection (odds ratio 4.62; 95% confidence interval 1.83 to 11.70; p =  0.001). TV infection was high amongst pregnant women. Therefore, routine testing for this sexually transmitted infection is encouraged for proper management.

Trichomonas vaginalis Motility Is Blocked by Drug-Free Thermosensitive Hydrogel

Trichomonas vaginalis motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize T. vaginalis was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from x, y coordinates during time. Major results are that T. vaginalis exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest T. vaginalis specimen moves with a velocity of 19 μm/s. Observation of T. vaginalis movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of T. vaginalis were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent T. vaginalis attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.

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.

Composite thermoresponsive hydrogel with auranofin-loaded nanoparticles for topical treatment of vaginal trichomonad infection

Trichomonas vaginalis is responsible for the most common non-viral sexually-transmitted disease worldwide. Standard treatment is with oral nitro-heterocyclic compounds, metronidazole or tinidazole, but resistance to these drugs is emerging and adverse effects can be problematic. Topical treatment offers potential benefits for increasing local drug concentrations and efficacy, while reducing systemic drug exposure, but no topical strategies are currently approved for trichomoniasis. The anti-rheumatic drug, auranofin (AF), was recently discovered to have significant trichomonacidal activity, but has a long plasma half-life and significant adverse effects. Here, we used this drug as a model to develop a novel topical formulation composed of AF-loaded nanoparticles (NP) embedded in a thermoresponsive hydrogel for intravaginal administration. The AF-NP composite gel showed sustained drug release for at least 12 h, and underwent sol-gel transition with increased viscoelasticity within a minute. Intravaginal administration in mice showed excellent NP retention for >6 h and markedly increased local AF levels, but reduced plasma and liver levels compared to oral treatment with a much higher dose. Furthermore, intravaginal AF-NP gel greatly outperformed oral AF in eliminating vaginal trichomonad infection in mice, while causing no systemic or local toxicity. These results show the potential of the AF-NP hydrogel formulation for effective topical therapy of vaginal infections.

Mitochondrial dynamics in parasitic protists

The shape and number of mitochondria respond to the metabolic needs during the cell cycle of the eukaryotic cell. In the best-studied model systems of animals and fungi, the cells contain many mitochondria, each carrying its own nucleoid. The organelles, however, mostly exist as a dynamic network, which undergoes constant cycles of division and fusion. These mitochondrial dynamics are driven by intricate protein machineries centered around dynamin-related proteins (DRPs). Here, we review recent advances on the dynamics of mitochondria and mitochondrion-related organelles (MROs) of parasitic protists. In contrast to animals and fungi, many parasitic protists from groups of Apicomplexa or Kinetoplastida carry only a single mitochondrion with a single nucleoid. In these groups, mitochondrial division is strictly coupled to the cell cycle, and the morphology of the organelle responds to the cell differentiation during the parasite life cycle. On the other hand, anaerobic parasitic protists such as Giardia, Entamoeba, and Trichomonas contain multiple MROs that have lost their organellar genomes. We discuss the function of DRPs, the occurrence of mitochondrial fusion, and mitophagy in the parasitic protists from the perspective of eukaryote evolution.