Trichomoniasis and its treatment

Vaginal Tritrichomonas foetus infection in mice as an in vivo model for drug development against Trichomonas vaginalis

Trichomonas vaginalis is the causative agent of the common sexually transmitted disease, trichomoniasis, which affects more than a hundred million people worldwide. Metronidazole and tinidazole, agents belonging to the 5-nitroheterocyclic class of antimicrobials, are most often used to treat infection, but increased resistance has been reported and adverse effects of these drugs can be significant. Consequently, an urgent need exists for the development of novel drug entities against trichomoniasis. Critical for antimicrobial drug development is the demonstration of in vivo efficacy. Murine models of vaginal T. vaginalis infection are unreliable for unknown reasons. Meanwhile, murine infections with the related bovine pathogen, Tritrichomonas foetus, tend to be more robust, although susceptibility to different antimicrobials might differ from T. vaginalis. Here, we explored the utility of T. foetus infection as a surrogate model for drug development against T. vaginalis. Four different T. foetus strains caused robust vaginal infection in young mice, while none of four diverse T. vaginalis strains did. Comparison of drug susceptibility profiles revealed that T. foetus and T. vaginalis were similarly susceptible to a range of 5-nitroheterocyclic and gold(I) compounds. By comparison, proteasome inhibitors were 10- to 15-fold less active against T. foetus than T. vaginalis, although one of the proteasome inhibitors, bortezomib, had low micromolar activity or better against multiple strains of both trichomonads. Different strains of T. foetus were used to demonstrate the utility of the murine vaginal infection models for in vivo efficacy testing, including for bortezomib and a gold(I) compound. The differences in susceptibility to proteasome inhibitors may be partially explained by differences in the proteasome subunit sequences between the two trichomonads, although the functional relevance of the proteasome was similar in both organisms. These findings indicate that T. foetus can serve as a reliable surrogate model for T. vaginalis in vitro and in murine infections in vivo, but caution must be exercised for specific drug classes with targets, such as the proteasome, that may display genetic divergence between the trichomonads.

Updates on Sexually Transmitted Urethro-cystitis

Purpose of Review

We performed recent literature review with the aim to address the updates in diagnosis and management of sexually transmitted urethro-cystitis.

Recent Findings

There are multiple, recently published studies that collectively lead to an organized stepwise plan for diagnosis and management of sexually transmitted urethro-cystitis.

Summary

Sexually transmitted urethro-cystitis is a common health condition that can be managed efficiently if the appropriate steps are taken in diagnosis and management.

Characterizing the Fused TvG6PD::6PGL Protein from the Protozoan Trichomonas vaginalis, and Effects of the NADP+ Molecule on Enzyme Stability

This report describes a functional and structural analysis of fused glucose-6-phosphate dehydrogenase dehydrogenase-phosphogluconolactonase protein from the protozoan Trichomonas vaginalis (T. vaginalis). The glucose-6-phosphate dehydrogenase (g6pd) gene from T. vaginalis was isolated by PCR and the sequence of the product showed that is fused with 6pgl gene. The fused Tvg6pd::6pgl gene was cloned and overexpressed in a heterologous system. The recombinant protein was purified by affinity chromatography, and the oligomeric state of the TvG6PD::6PGL protein was found as tetramer, with an optimal pH of 8.0. The kinetic parameters for the G6PD domain were determined using glucose-6-phosphate (G6P) and nicotinamide adenine dinucleotide phosphate (NADP+) as substrates. Biochemical assays as the effects of temperature, susceptibility to trypsin digestion, and analysis of hydrochloride of guanidine on protein stability in the presence or absence of NADP+ were performed. These results revealed that the protein becomes more stable in the presence of the NADP+. In addition, we determined the dissociation constant for the binding (Kd) of NADP+ in the protein and suggests the possible structural site in the fused TvG6PD::6PGL protein. Finally, computational modeling studies were performed to obtain an approximation of the structure of TvG6PD::6PGL. The generated model showed differences with the GlG6PD::6PGL protein (even more so with human G6PD) despite both being fused.

Management of Urethritis: Is It Still the Time for Empirical Antibiotic Treatments?

CONTEXT

Urethritis prevalence in Europe changed in the last years due to both the increase of migratory streams from North Africa and the more frequent exposition of males to relevant risk factors. Owing to these reasons, urethritis treatment should be optimized by accurate microbiological investigations to avoid the risk of persistence, recurrence, or reinfection.

OBJECTIVE

The aim of this systematic review is to optimize the treatments for urethritis and investigate the applicability of nucleic acid amplification test (NAAT) as the primary microbiological investigation.

EVIDENCE ACQUISITION

A literature search in Medline, Cochrane, and Google Scholar databases was conducted up to June 2018. Subject headings were selected as follows: Urethritis OR gonococcal urethritis OR non-gonococcal urethritis AND Antibiotics OR Recurrence. A total of 528 abstracts were identified and selected. Finally, 12 full-text articles were selected for a qualitative synthesis. The Preferred Reported Items for Systematic Reviews and Meta-Analyses statement was used to perform an accurate research checklist and report.

EVIDENCE SYNTHESIS

Empirical treatments are no more recommended, although a broad spectrum of antibiotic therapy may be initiated while awaiting the results from pathogens' microbiological characterization. First-line treatment for gonococcal urethritis consists of a single dose of ceftriaxone/azithromycin combined therapy. Specific therapies should be initiated for nongonococcal urethritis according to each single pathogen involved in the infection process. Owing to this reason, NAAT is mandatory in the clinical approach to the disease, although the Gram stain of urethral discharge or smear remains applicable for some less frequent nongonococcal urethritis. Moreover, the urethritis "modern view" also includes noninfectious etiologies that occurred after traumas or injection of irritating compounds. Sexual abstinence of at least 7 d should be observed from the start of treatment to avoid reinfection, while sexual partners should evenly be treated.

CONCLUSIONS

The treatment of urethritis implies accurate determination of pathogens involved in the infection process by NAAT with subsequent appropriate antibiotic therapy, thus avoiding the risk of antibiotic resistance and overuse of antibiotics indicated for empirical treatments. The population exposed to relevant risk factors should be adequately informed about the increased risk of developing infections and motivated toward the intensive use of condoms during sexual intercourses.

PATIENT SUMMARY

Urethritis is a sexually transmitted disease generally characterized by urethral discharge or other symptoms such as itching, tingling, and apparent difficulties in having a regular urinary flow. Microbiological investigations are mandatory to obtain satisfactory results from the treatment. Multiple antibiotic treatments are often necessary due to the high risk of multiple pathogens responsible for the disease. Similarly, sexual partners should be investigated and treated in the same way. Several risk factors such as immunodeficiency, multiple sexual partners, homo- and bisexuality, and alcohol abuse may be related to the disease. In these cases, the use of condom is strongly recommended.

Membrane localization of a Myb3 transcription factor regulated by a TvCyP1 cyclophilin in the parasitic protozoan Trichomonas vaginalis

In Trichomonas vaginalis, a TvCyP1 cyclophilin was previously demonstrated to regulate the nuclear translocation of Myb1 and Myb3, which respectively repress and activate transcription of an adhesion protein ap65-1 gene. In the present study, TvCyP1 was found to bind to Myb3 at sites spanning ⁵⁴ Gly-Pro⁵⁵ and ⁷² Gly-Pro⁷³ with differential affinities. When Gly⁵⁴ and Gly⁷² in Myb3 were both mutated, the mutant protein was restrained on outer membranes of hydrogenosomes and some cytoplasmic vesicles. In the purified Myb3 protein complex, a high molecular weight Myb3-interacting protein (Myb3IP_hmw ) and a 72-kDa heat shock protein (TvHSP72) were identified and characterized, with direct binding of Myb3 to Myb3IP_hmw and TvHSP72 confirmed in vitro. When cell lysates were fractionated by the differential and gradient centrifugations, TvCyP1 and Myb3 were always associated with membrane fractions enriched with Myb3IP_hmw and Myb1, as well as hydrogenosomes and V_Myb organelle fractions. Mutations of Gly⁵⁴ and/or Gly⁷² resulted in membrane redistribution of Myb3 and the aberrant assembly of the Myb3 protein complex. Consistent with these findings, the involvement of TvCyP1 in membrane distribution of Myb3, and dissociation of Myb3 from TvCyP1 protein complex were demonstrated, with direct interactions between TvCyP1 and Myb3IP_hmw and that between TvCyP1 and TvHSP72, confirmed in vitro. These observations suggest that TvCyP1 directly binds to Myb3 and some of its interacting proteins to mediate serial conformational switches of Myb3 for its transition from the membrane compartments toward the nucleus.

Strategies for Prevention and Treatment of Trichomonas vaginalis Infections

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

Eicosapentaenoic Acid Modulates Trichomonas vaginalis Activity

Trichomonas vaginalis is a sexually transmitted parasite and, while it is often asymptomatic in males, the parasite is associated with disease in both sexes. Metronidazole is an effective treatment for trichomoniasis, but resistant strains have evolved and, thus, it has become necessary to investigate other possible therapies. In this study, we examined the effects of native and oxidized forms of the sodium salts of eicosapentaenoic, docosahexaenoic, and arachidonic acids on T. vaginalis activity. Eicosapentaenoic acid was the most toxic with 190 and 380 μM causing approximately 90% cell death in Casu2 and ATCC 50142 strains, respectively. In contrast, oxidized eicosapentaenoic acid was the least toxic, requiring > 3 mM to inhibit activity, while low levels (10 μM) were associated with increased parasite density. Mass spectrometric analysis of oxidized eicosapentaenoic acid revealed C20 products containing one to six additional oxygen atoms and various degrees of bond saturation. These results indicate that eicosapentaenoic acid has different effects on T. vaginalis survival, depending on whether it is present in the native or oxidized form. A better understanding of lipid metabolism in T. vaginalis may facilitate the design of synthetic fatty acids that are effective for the treatment of metronidazole-resistant T. vaginalis.

Trichomonas vaginalis: Clinical relevance, pathogenicity and diagnosis

Trichomonas vaginalis is the etiological agent of trichomoniasis, the most prevalent non-viral sexually transmitted disease worldwide. Trichomoniasis is a widespread, global health concern and occurring at an increasing rate. Infections of the female genital tract can cause a range of symptoms, including vaginitis and cervicitis, while infections in males are generally asymptomatic. The relatively mild symptoms, and lack of evidence for any serious sequelae, have historically led to this disease being under diagnosed, and under researched. However, growing evidence that T. vaginalis infection is associated with other disease states with high morbidity in both men and women has increased the efforts to diagnose and treat patients harboring this parasite. The pathology of trichomoniasis results from damage to the host epithelia, caused by a variety of processes during infection and recent work has highlighted the complex interactions between the parasite and host, commensal microbiome and accompanying symbionts. The commercial release of a number of nucleic acid amplification tests (NAATs) has added to the available diagnostic options. Immunoassay based Point of Care testing is currently available, and a recent initial evaluation of a NAAT Point of Care system has given promising results, which would enable testing and treatment in a single visit.

Effect of Nigella sativa alcoholic extract and oil, as well as Phaseolus vulgaris (kidney bean) lectin on the ultrastructure of Trichomonas vaginalis trophozoites

Trichomonas vaginalis is a parasitic protozoan that is the aetiological agent of trichomoniasis, the most common non-viral sexually transmitted disease worldwide. Currently, the compound of choice for the treatment of T. vaginalis infections is metronidazole, however, it has many side effects and an increase in metronidazole-resistant trichomoniasis has been observed. Medicinal plants could be a source of new antiprotozoal drugs with high activity, low toxicity and lower price. The present work was carried out to investigate the therapeutic potential of Nigella sativa alcoholic extract and oil, as well as Phaseolus vulgaris (kidney bean) lectin and their in vitro activity on the ultrastructure of T. vaginalis trophozoites in comparison to metronidazole, as detected by transmission electron microscope. Both N. sativa oil and P. vulgaris lectin showed high toxic effect as evidenced by severe cell damage with cytoplasmic and nuclear destruction, while the effect of N. sativa alcoholic extract was moderate. Therefore, these two extracts could offer an effective, cheaper and more safe alternative for metronidazole in treatment of trichomoniasis.

Signal transduction triggered by iron to induce the nuclear importation of a Myb3 transcription factor in the parasitic protozoan Trichomonas vaginalis

Iron was previously shown to induce rapid nuclear translocation of a Myb3 transcription factor in the protozoan parasite, Trichomonas vaginalis. In the present study, iron was found to induce a transient increase in cellular cAMP, followed by the nuclear influx of Myb3, whereas the latter was also induced by 8-bromo-cyclic AMP. Iron-inducible cAMP production and nuclear influx of Myb3 were inhibited by suramin and SQ22536, respective inhibitors of the Gα subunit of heterotrimeric G proteins and adenylyl cyclases. In contrast, the nuclear influx of Myb3 induced by iron or 8-bromo-cAMP was delayed or inhibited, respectively, by H89, the inhibitor of protein kinase A. Using liquid chromatography-coupled tandem mass spectrometry, Thr(156) and Lys(143) in Myb3 were found to be phosphorylated and ubiquitinated, respectively. These modifications were induced by iron and inhibited by H89, as shown by immunoprecipitation-coupled Western blotting. Iron-inducible ubiquitination and nuclear influx were aborted in T156A and K143R, but T156D was constitutively ubiquitinated and persistently localized to the nucleus. Myb3 was phosphorylated in vitro by the catalytic subunit of a T. vaginalis protein kinase A, TvPKAc. A transient interaction between TvPKAc and Myb3 and the phosphorylation of both proteins were induced in the parasite shortly after iron or 8-bromo-cAMP treatment. Together, these observations suggest that iron may induce production of cAMP and activation of TvPKAc, which then induces the phosphorylation of Myb3 and subsequent ubiquitination for accelerated nuclear influx. It is conceivable that iron probably exerts a much broader impact on the physiology of the parasite than previously thought to encounter environmental changes.

Unexpected properties of NADP-dependent secondary alcohol dehydrogenase (ADH-1) in Trichomonas vaginalis and other microaerophilic parasites

•

Trichomonas vaginalis NADPH-dependent alcohol dehydrogenase-1 (ADH-1) reduces acetaldehyde and acetone, and oxidizes 2-propanol.

•

In addition to its canonical function, a strong reducing background activity was observed.

•

All reactions catalyzed by ADH-1 are strongly inhibited by CoA.

•

These observations also apply for the parasites Entamoeba histolytica and Tritrichomonas foetus, but not for Giardia lamblia which lacks ADH-1.

Our previous observation that NADP-dependent secondary alcohol dehydrogenase (ADH-1) is down-regulated in metronidazole-resistant Trichomonas vaginalis isolates prompted us to further characterise the enzyme. In addition to its canonical enzyme activity as a secondary alcohol dehydrogenase, a pronounced, so far unknown, background NADPH-oxidising activity in absence of any added substrate was observed when the recombinant enzyme or T. vaginalis extract were used. This activity was strongly enhanced at low oxygen concentrations. Unexpectedly, all functions of ADH-1 were efficiently inhibited by coenzyme A which is a cofactor of a number of key enzymes in T. vaginalis metabolism, i.e. pyruvate:ferredoxin oxidoreductase (PFOR). These observations could be extended to Entamoeba histolytica and Tritrichomonas foetus, both of which have a homologue of ADH-1, but not to Giardia lamblia which lacks an NADP-dependent secondary alcohol dehydrogenase.

Although we could not identify the substrate of the observed background activity, we propose that ADH-1 functions as a major sink for NADPH in microaerophilic parasites at low oxygen tension.

Host-parasite interaction: parasite-derived and -induced proteases that degrade human extracellular matrix

Parasitic protozoa are among the most important pathogens worldwide. Diseases such as malaria, leishmaniasis, amoebiasis, giardiasis, trichomoniasis, and trypanosomiasis affect millions of people. Humans are constantly threatened by infections caused by these pathogens. Parasites engage a plethora of surface and secreted molecules to attach to and enter mammalian cells. The secretion of lytic enzymes by parasites into host organs mediates critical interactions because of the invasion and destruction of interstitial tissues, enabling parasite migration to other sites within the hosts. Extracellular matrix is a complex, cross-linked structure that holds cells together in an organized assembly and that forms the basement membrane lining (basal lamina). The extracellular matrix represents a major barrier to parasites. Therefore, the evolution of mechanisms for connective-tissue degradation may be of great importance for parasite survival. Recent advances have been achieved in our understanding of the biochemistry and molecular biology of proteases from parasitic protozoa. The focus of this paper is to discuss the role of protozoan parasitic proteases in the degradation of host ECM proteins and the participation of these molecules as virulence factors. We divide the paper into two sections, extracellular and intracellular protozoa.

What would we do without metronidazole?

Metronidazole is a treatment of choice for several types of infections, but coexisting conditions or concomitant medications may preclude its use. Although tinidazole, a newer nitroimidazole, may be an option in cases where drug interactions make the use of metronidazole inadvisable, similar absolute contraindications exist. In situations where nitroimidazole use is contraindicated or inadvisable, clinicians may have difficulty deciding on efficacious treatment options. For the treatment of trichomoniasis, alternatives include furazolidone, clotrimazole, nonoxynol-9 or paromomycin. Alternatives for bacterial vaginosis include clindamycin topically or systemically. For giardiasis, alternative options include paromomycin, nitazoxanide or the antihelminthic benzimidazoles. Alternatives for Clostridium difficile are varied, including oral vancomycin, nitazoxanide and rifaximin. Although options are limited, alternative therapies for treatment of patients with absolute contraindications to the nitroimidazole antibiotics are available.

Down-regulation of flavin reductase and alcohol dehydrogenase-1 (ADH1) in metronidazole-resistant isolates of Trichomonas vaginalis

The microaerophilic parasite Trichomonas vaginalis is a causative agent of painful vaginitis or urethritis, termed trichomoniasis, and can also cause preterm delivery or stillbirth. Treatment of trichomoniasis is almost exclusively based on the nitroimidazole drugs metronidazole and tinidazole. Metronidazole resistance in T. vaginalis does occur and is often associated with treatment failure. In most cases, metronidazole-resistant isolates remain susceptible to tinidazole, but cross resistance between the two closely related drugs can be a problem. In this study we measured activities of thioredoxin reductase and flavin reductase in four metronidazole-susceptible and five metronidazole-resistant isolates. These enzyme activities had been previously found to be downregulated in T. vaginalis with high-level metronidazole resistance induced in the laboratory. Further, we aimed at identifying factors causing metronidazole resistance and compared the protein expression profiles of all nine isolates by application of two-dimensional gel electrophoresis (2DE). Thioredoxin reductase activity was nearly equal in all strains assayed but flavin reductase activity was clearly down-regulated, or even absent, in metronidazole-resistant strains. Since flavin reductase has been shown to reduce oxygen to hydrogen peroxide, its down-regulation could significantly contribute to the impairment of oxygen scavenging as reported by others for metronidazole-resistant strains. Analysis by 2DE revealed down-regulation of alcohol dehydrogenase 1 (ADH1) in strains with reduced sensitivity to metronidazole, an enzyme that could be involved in detoxification of intracellular acetaldehyde.

Diagnosis of vaginal discharge by wet mount microscopy: a simple and underrated method

Vaginal discharge is highly variable in quality and quantity among different individuals, and even in the same individual during different periods of life. Vaginal discharge is most commonly caused by infection with sexually transmitted organisms or increased colonization by different facultative pathogenic microorganisms (i.e., Gardnerella vaginalis). Noninfectious causes of vaginal discharge are quite rare (10% noninfectious as compared to 90% infectious causes). Most common in women with a vaginal infection is bacterial vaginosis (40%-50% of cases), followed by vulvovaginal candidosis (20%-25%), and then trichomoniasis (15%-20%). If infection is suspected as the primary cause, a sample of the vaginal discharge should be taken and examined microscopically. When evaluating vaginal secretions by phase-contrast wet mount microscopy, knowledge of what is normal versus abnormal is very important. Knowledge of the sensitivity and specificity of wet mount microscopy in different clinical settings is also important.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians

LEARNING OBJECTIVES

After completing this CME activity, physicians should be better able to evaluate lifetime changes in vaginal secretions, characterize the physiological and pathological appearance of vaginal discharge, assess the clinical practicality and usefulness of wet mount microscopy and use wet mount microscopy to diagnose bacterial vaginosis and other common vaginal infections.

Murine models of vaginal trichomonad infections

Trichomonas vaginalis and Tritrichomonas foetus cause common sexually transmitted infections in humans and cattle, respectively. Mouse models of trichomoniasis are important for pathogenic and therapeutic studies. Here, we compared murine genital infections with T. vaginalis and T. foetus. Persistent vaginal infection with T. foetus was established with 100 parasites but T. vaginalis infection required doses of 10(6), perhaps because of greater susceptibility to killing by mouse vaginal polymorphonuclear leukocytes. Infection with T. vaginalis persisted longest after combined treatment of mice with estrogen and dexamethasone, whereas infection was only short-lived when mice were given estrogen or dexamethasone alone, co-infected with Lactobacillus acidophilus, and/or pretreated with antibiotics. Infection rates were similar with metronidazole-resistant (MR) and metronidazole-sensitive (MS) T. vaginalis. High dose but not low dose metronidazole treatment controlled infection with MS better than MR T. vaginalis. These murine models will be valuable for investigating the pathogenesis and treatment of trichomoniasis.

Refractory Trichomoniasis in HIV-positive and HIV-negative Subjects

Trichomonas vaginalis, a common pathogen, remains widely unknown to the public. Its clinical consequences include upper genital tract infection, increased risk of preterm delivery, and increased risk of HIV transmission. Diagnostic tests, especially in men, have historically had low sensitivity, but the recent development of rapid, reliable point-of-care testing is a step toward improved detection. Reliable treatments for trichomoniasis are limited to the nitroimidazoles, and options for cases with either hypersensitivity or resistance remain limited. In select resistant cases, alternatives, most notably paromomycin, may play a role. A complex interaction exists between T. vaginalis and HIV, whereby women with trichomoniasis are at increased risk for HIV and vice versa. It is hoped that diagnosis and treatment of trichomoniasis in women at high risk for HIV may help to lower the incidence of both infections.

Trichomonas vaginalis infection among women in a low prevalence setting

Objectives: Trichomonas vaginalis has become rare in Australian cities but remains endemic in some remote regions. We describe the prevalence and associations of infection among women attending an urban Australian sexual health clinic. Methods: A retrospective case control study was conducted with women diagnosed with T. vaginalis at Sydney Sexual Health Centre between January 1992 and December 2006. Proforma medical records for all women were reviewed to extract demographic, behavioural and diagnostic variables using a predefined data collection instrument. Results: Over the 15-year period, 123 cases of T. vaginalis were diagnosed, with a prevalence of 0.40%. Factors independently associated with infection were older age, vaginitis symptoms (adjusted odds ratio (AOR) 6.47; 95% confidence interval (CI), 3.29–12.7), sex with a partner from outside Australia (AOR 2.33; 95% CI, 1.18–4.62), a concurrent (AOR 3.65; 95% CI, 1.23–10.8) or past (AOR 2.67; 95% CI, 1.28–5.57) sexually transmissible infection, injecting drugs (AOR 7.27; 95% CI, 1.43–36.8), and never having had a Papanicolaou smear (AOR 7.22; 95% CI, 2.81–18.9). Conclusions: T. vaginalis infection was rare in women attending our urban clinic. Rarity, combined with an association with sex outside Australia, points to imported infections accounting for a large proportion of T. vaginalis infections in an urban population. The association with never having had cervical cancer screening, along with injecting drug use, likely reflects an increased prevalence in those with reduced access to health services or poor health seeking behaviours.

The tropical brown alga Lobophora variegata: a source of antiprotozoal compounds

Lobophora variegata, a brown alga collected from the coast of the Yucatan peninsula, Mexico, was studied for antiprotozoal activity against Giardia intestinalis, Entamoeba histolytica and Trichomonas vaginalis. The whole extract showed the highest activity against T. vaginalis, with an IC(50) value of 3.2 microg/mL. For the fractions, the best antiprotozoal activity was found in non-polar fractions. The chloroform fraction of the extract contained a major sulfoquinovosyldiacylglycerol (SQDG), identified as 1-O-palmitoyl-2-O-myristoyl-3-O-(6'''-sulfo-alpha-D-quinovopyranosyl)-glycerol (1), together with small amounts of 1,2-di-O-palmitoyl-3-O-(6'''-sulfo-alpha-D-quinovopyranosyl)-glycerol (2) and a new compound identified as 1-O-palmitoyl-2-O-oleoyl-3-O-(6'''-sulfo-alpha-D-quinovopyranosyl)-glycerol (3). Their structures were elucidated on the basis of chemical and enzymatic hydrolysis and careful analysis of FAB-MS and NMR spectroscopic data. This is the first report on the isolation of SQDGs from L. variegata. The mixture of 1-3 showed good activity against E. histolytica and moderate activity against T. vaginalis with IC(50s) of 3.9 and 8.0 microg/mL, respectively, however, the activity of 1-3 is not as effective as metronidazole. These results afford ground information for the potential use of the whole extract and fractions of this species in protozoal infections.

Trichomonas vaginalis vast BspA-like gene family: evidence for functional diversity from structural organisation and transcriptomics

Background

Trichomonas vaginalis is the most common non-viral human sexually transmitted pathogen and importantly, contributes to facilitating the spread of HIV. Yet very little is known about its surface and secreted proteins mediating interactions with, and permitting the invasion and colonisation of, the host mucosa. Initial annotations of T. vaginalis genome identified a plethora of candidate extracellular proteins.

Results

Data mining of the T. vaginalis genome identified 911 BspA-like entries (TvBspA) sharing TpLRR-like leucine-rich repeats, which represent the largest gene family encoding potential extracellular proteins for the pathogen. A broad range of microorganisms encoding BspA-like proteins was identified and these are mainly known to live on mucosal surfaces, among these T. vaginalis is endowed with the largest gene family. Over 190 TvBspA proteins with inferred transmembrane domains were characterised by a considerable structural diversity between their TpLRR and other types of repetitive sequences and two subfamilies possessed distinct classic sorting signal motifs for endocytosis. One TvBspA subfamily also shared a glycine-rich protein domain with proteins from Clostridium difficile pathogenic strains and C. difficile phages. Consistent with the hypothesis that TvBspA protein structural diversity implies diverse roles, we demonstrated for several TvBspA genes differential expression at the transcript level in different growth conditions. Identified variants of repetitive segments between several TvBspA paralogues and orthologues from two clinical isolates were also consistent with TpLRR and other repetitive sequences to be functionally important. For one TvBspA protein cell surface expression and antibody responses by both female and male T. vaginalis infected patients were also demonstrated.

Conclusions

The biased mucosal habitat for microbial species encoding BspA-like proteins, the characterisation of a vast structural diversity for the TvBspA proteins, differential expression of a subset of TvBspA genes and the cellular localisation and immunological data for one TvBspA; all point to the importance of the TvBspA proteins to various aspects of T. vaginalis pathobiology at the host-pathogen interface.

Detecting and treating common sexually transmitted diseases

In the UK, many sexually transmitted infections (STIs) are best managed in conjunction with an appropriate specialist, for example, a genitourinary medicine practitioner or a Microbiologist. In most of the world, however, gynaecologists routinely manage STIs in women. This article focuses on the most important infections in women, and those in which management is changing. It also addresses the current status, and new developments around the syndrome of pelvic inflammatory disease (PID), which essentially is an STI.

Horizontal gene transfer in eukaryotic parasites: a case study of Entamoeba histolytica and Trichomonas vaginalis

Over the past few years it has become apparent that horizontal gene transfer (HGT) has played an important role in the evolution of pathogenic prokaryotes. What is less clear is the exact role that HGT has played in shaping the metabolism of eukaryotic organisms. The main problems are the reliable inference of HGT on a genomic scale as well as the functional assignment of genes in these poorly studied organisms. We have screened the completed genomes of the protists Entamoeba histolytica and Trichomonas vaginalis for cases of HGT from prokaryotes. Using a fast primary screen followed by a conservative phylogenetic approach, we found 68 and 153 recent cases of HGT in the respective organisms. The majority of transferred genes that fall into functional categories code for enzymes involved in metabolism. We found a broad range of prokaryotic lineages represented among the donors, but organisms that share similar environmental niches with E. histolytica and T. vaginalis, such as the gut and the vaginal mucosa, dominate.

Evaluation of selected tropical seaweeds for in vitro anti-trichomonal activity

ETHNOPHARMACOLOGICAL RELEVANCE

Human parasitic infections are a serious problem in tropical and sub-tropical developing countries. Trichomoniasis, responsible for the annual infection of 180 million people, is a common sexually transmitted disease caused by the protozoan Trichomonas vaginalis. Traditionally seaweeds have been used in folk medicine by coastal people in Asia and the Caribbean to treat parasitic infections and are a valuable source of novel anti-trichomonals.

AIM OF THE STUDY

In our search for therapeutical alternatives to anti-protozoal chemotherapy, we collected a selection of 25 tropical seaweeds (12 Rhodophyta, 5 Phaeophyta and 8 Chlorophyta) from the coast of Yucatan (Mexico) in order to undertake ethnopharmacological and chemotaxonomic investigations.

MATERIALS AND METHODS

Organic algal extracts were tested for their anti-trichomonal properties on the growth inhibition of Trichomonas vaginalis. The cytotoxicity of seaweed extracts on mammal cell lines was also assessed.

RESULTS

The results indicated that 44% of the seaweeds studied had high to moderate anti-trichomonal activity. Lobophora variegata and Udotea conglutinata showed the maximal anti-trichomonal activity with IC(50) values of 1.39 and 1.66microg/ml, respectively, with good selectivity.

CONCLUSIONS

Lobophora variegata and Udotea conglutinata demonstrated promising anti-trichomonal potential and have been selected for further bio-guided fractionation and isolation of active anti-trichomonal compounds.

Evaluation of the OSOM Trichomonas rapid test versus wet preparation examination for detection of Trichomonas vaginalis vaginitis in specimens from women with a low prevalence of infection

The OSOM Trichomonas rapid test (OSOM Trich) was compared to the wet preparation examination (WP) for the detection of Trichomonas vaginalis vaginitis in women with a low prevalence of infection. A total of 19/1,009 (2%) women had T. vaginalis infection. OSOM Trich had very good performance, with sensitivity, specificity, efficiency, positive predictive value, and negative predictive value of 94.7, 100, 99.9, 100, and 99.9%, respectively. The implementation of OSOM Trich would decrease labor costs.

Management of trichomonas vaginalis in women with suspected metronidazole hypersensitivity

BACKGROUND/OBJECTIVE

Standard treatment for Trichomonas vaginalis is metronidazole or tinidazole. Hypersensitivity to these drugs has been documented but is poorly understood. Desensitization is an option described in limited reports of women with hypersensitivity to nitroimidazoles. The purpose of this analysis is to improve documentation of management for trichomonas infections among women with metronidazole hypersensitivity.

STUDY DESIGN

Clinicians who consulted Centers for Disease Control and Prevention concerning patients with suspected hypersensitivity to metronidazole were provided with treatment options and asked to report outcomes.

RESULTS

From September 2003-September 2006, complete information was obtained for 59 women. The most common reactions were urticaria (47%) and facial edema (11%). Fifteen of these women (25.4%) were treated with metronidazole desensitization and all had eradication of their infection. Seventeen women (28.8%) were treated with alternative intravaginal drugs, which were less successful; 5 of 17 infections (29.4%) were eradicated.

CONCLUSION

Metronidazole desensitization was effective in the management of women with nitroimidazole hypersensitivity.

Definition and classification of abnormal vaginal flora

Studying the vaginal microflora is not only fascinating, with many discoveries to be made, it is also a very practical way to help women get rid of bothersome and sometimes dangerous infections. Gram-stained vaginal preparations, Pap smears, specific cultures, and nucleic acid detection techniques can be used to diagnose the constituents of the vaginal flora, but in trained hands office-based microscopy of a fresh vaginal smear, preferably using a x400 magnification phase-contrast microscope, allows almost every diagnosis and combination of diagnoses imaginable. In this chapter I will address the pros and cons of the tools that are in use to study vaginal flora, and discuss the different types of bacterial flora and the difficulties encountered in reaching the correct diagnosis of pathological conditions. The 'intermediate flora' is addressed separately, and a new entity--'aerobic vaginitis'--is discussed. Future research should focus on the interaction between infecting microorganisms and host defence mechanisms, as both together generate the pathogenicity of these conditions.