The clinical spectrum ofTrichomonas vaginalisinfection and challenges to management

The Past, Present, and Future in the Diagnosis of a Neglected Sexually Transmitted Infection: Trichomoniasis

More than one million curable sexually transmitted infections occur every day. Trichomonas vaginalis is one of the main infections responsible for these epidemiological data; however, the diagnosis of this protozoan is still mainly based on microscopic and culture identification. The commercialization of immunological tests and the development of molecular techniques have improved the sensitivity of classical methods. Nevertheless, the fact that trichomoniasis is a neglected parasitic infection hinders the development of novel techniques and their implementation in routine diagnosis. This review article shows the different methods developed to identify T. vaginalis in population and the difficulties in diagnosing male and asymptomatic patients. The importance of including this parasite in routine gynecological screening, especially in pregnant women, and the importance of considering T. vaginalis as an indicator of high-risk sexual behavior are also discussed.

Shifting from Ammonium to Phosphonium Salts: A Promising Strategy to Develop Next-Generation Weapons against Biofilms

Since they are difficult and sometimes impossible to treat, infections sustained by multidrug-resistant (MDR) pathogens, emerging especially in nosocomial environments, are an increasing global public health concern, translating into high mortality and healthcare costs. In addition to having acquired intrinsic abilities to resist available antibiotic treatments, MDR bacteria can transmit genetic material encoding for resistance to non-mutated bacteria, thus strongly decreasing the number of available effective antibiotics. Moreover, several pathogens develop resistance by forming biofilms (BFs), a safe and antibiotic-resistant home for microorganisms. BFs are made of well-organized bacterial communities, encased and protected in a self-produced extracellular polymeric matrix, which impedes antibiotics' ability to reach bacteria, thus causing them to lose efficacy. By adhering to living or abiotic surfaces in healthcare settings, especially in intensive care units where immunocompromised older patients with several comorbidities are hospitalized BFs cause the onset of difficult-to-eradicate infections. In this context, recent studies have demonstrated that quaternary ammonium compounds (QACs), acting as membrane disruptors and initially with a low tendency to develop resistance, have demonstrated anti-BF potentialities. However, a paucity of innovation in this space has driven the emergence of QAC resistance. More recently, quaternary phosphonium salts (QPSs), including tri-phenyl alkyl phosphonium derivatives, achievable by easy one-step reactions and well known as intermediates of the Wittig reaction, have shown promising anti-BF effects in vitro. Here, after an overview of pathogen resistance, BFs, and QACs, we have reviewed the QPSs developed and assayed to this end, so far. Finally, the synthetic strategies used to prepare QPSs have also been provided and discussed to spur the synthesis of novel compounds of this class. We think that the extension of the knowledge about these materials by this review could be a successful approach to finding effective weapons for treating chronic infections and device-associated diseases sustained by BF-producing MDR bacteria.

Essential Oils and Terpenic Compounds as Potential Hits for Drugs against Amitochondriate Protists

The human anaerobic or microaerophilic protists Giardia duodenalis, Entamoeba histolytica, and Trichomonas vaginalis are classified as amitochondriate parasites, a group of unicellular organisms that lack canonical mitochondria organelles. These microorganisms suffered adaptations to survive in hostile microenvironments and together represent an increasing threat to public health in developing countries. Nevertheless, the current therapeutic drugs to manage the infections are scarce and often cause several side effects. Furthermore, refractory cases associated with the emergence of parasitic resistance are concerns that guide the search for new pharmacological targets and treatment alternatives. Herein, essential oils and terpenic compounds with activity against amitochondriate parasites with clinical relevance are summarized and insights into possible mechanisms of action are made. This review aims to contribute with future perspectives for research with these natural products as potential alternatives for the acquisition of new molecules for the treatment of amitochondriate protists.

Is There Any Relationship between Trichomonas vaginalis Infection and Male Urethritis Risk? A Systematic Review and Meta-Analysis

Background. Male urethritis is one of the most common genital tract syndromes. Though the number of patients with urethritis is increasing worldwide, the cause of many cases of non-gonococcal urethritis (NGU) is still unknown. Objectives. This study aimed to delineate the association between Trichomonas vaginalis (T. vaginalis) infection and male urethritis. Methods. The literature was searched in PubMed, Scopus, and Web of Science databases using the search terms “urethritis,” “Trichomonas vaginalis,” “trichomoniasis,” and “male urethritis” up to February 2020. Overall risk difference(RD) was applied to assess the relationship between T. vaginalis infection and male urethritis. Results. In total, seven articles were included in this systematic review and meta-analysis study. Our meta-analysis involved the review of case-control studies, including 2,242 urethritis cases and 929 individuals as controls. Among subjects examined for trichomoniasis, in the case group, 211 males were infected, and in the control group, 32 individuals were infected. The overall risk difference (RD) was 0.06, and the total reported $p$ value was 0.00001. Although the result of our meta-analysis was not significant, it was shown that the risk of urethritis is 0.06 more in trichomoniasis patients than in the non-exposed group. Conclusion. Findings from the included papers showed that trichomoniasis is not a risk factor for male urethritis. Although trichomoniasis alone is not the main cause of urethritis, it can be considered one of the risk factors in male urethritis. Therefore, in the future, it is necessary to perform further studies to clarify the detailed association between T. vaginalis infection and urethritis risk in male patients.

Sexually Transmitted Infections Treatment Guidelines, 2021

These guidelines for the treatment of persons who have or are at risk for sexually transmitted infections (STIs) were updated by CDC after consultation with professionals knowledgeable in the field of STIs who met in Atlanta, Georgia, June 11-14, 2019. The information in this report updates the 2015 guidelines. These guidelines discuss 1) updated recommendations for treatment of Neisseria gonorrhoeae, Chlamydia trachomatis, and Trichomonas vaginalis; 2) addition of metronidazole to the recommended treatment regimen for pelvic inflammatory disease; 3) alternative treatment options for bacterial vaginosis; 4) management of Mycoplasma genitalium; 5) human papillomavirus vaccine recommendations and counseling messages; 6) expanded risk factors for syphilis testing among pregnant women; 7) one-time testing for hepatitis C infection; 8) evaluation of men who have sex with men after sexual assault; and 9) two-step testing for serologic diagnosis of genital herpes simplex virus. Physicians and other health care providers can use these guidelines to assist in prevention and treatment of STIs.

Role of Vaginal Microbiota Dysbiosis in Gynecological Diseases and the Potential Interventions

Vaginal microbiota dysbiosis, characterized by the loss of Lactobacillus dominance and increase of microbial diversity, is closely related to gynecological diseases; thus, intervention on microbiota composition is significant and promising in the treatment of gynecological diseases. Currently, antibiotics and/or probiotics are the mainstay of treatment, which show favorable therapeutic effects but also bring problems such as drug resistance and high recurrence. In this review, we discuss the role of vaginal microbiota dysbiosis in various gynecological infectious and non-infectious diseases, as well as the current and potential interventions.

Promising Anti-Protozoan Activities of Propolis (Bee Glue) as Natural Product: A Review

PURPOSE

Propolis (bee glue) is a resinous mixture of different plant exudates that possesses a wide range of biological and antimicrobial activities and has been used as a food supplement and in complementary medicine for centuries. Some researchers have proposed that propolis could be a potential curative compound against microbial agents such as protozoan parasitic infections by different and occasionally unknown mechanisms due to the immunoregulatory function and antioxidant capacity of this natural product.

METHODS

In this review, we concentrate on in vitro and in vivo anti-protozoan activities of propolis extracts/fractions in the published literature.

RESULTS

In Leishmania, propolis inhibits the proliferation of promastigotes and produces an anti-inflammatory effect via the inhibition of nitric oxide (NO) production. In addition, it increases macrophage activation, TLR-2, TNF-α, IL-4, IL-17 production, and downregulation of IL-12. In Plasmodium and Trypanosoma, propolis inhibits the parasitemia, improving anemia and increasing the IFN-γ, TNF-α, and GM-CSF cytokines levels, most likely due to its strong immunomodulatory activity. Moreover, propolis extract arrests proliferation of T. cruzi, because it has aromatic acids and flavonoids. In toxoplasmosis, propolis increases the specific IgM and IgG titers via decreasing the serum IFN-γ, IL-1, and IL-6 cytokines levels in the rats infected with T. gondii. In Cryptosporidium and Giardia, it decreases oocysts shedding due to phytochemical constituents, particularly phenolic compounds, and increases the number of goblet cells. Propolis inhibits the growth of Blastocystis, possibly by apoptotic mechanisms like metronidazole. Unfortunately, the mechanism action of propolis' anti-Trichomonas and anti-Acanthamoeba is not well-known yet.

CONCLUSION

Reviewing the related literature could highlight promising antimicrobial activities of propolis against intracellular and extracellular protozoan parasites; this could shed light on the exploration of more effective drugs for the treatment of protozoan parasitic infections in the near future.

Metronidazole-resistant trichomoniasis: Two Canadian cases

Metronidazole-resistant trichomoniasis is a health burden for patients, and limited access to susceptibility testing and treatment is a challenge for Canadian clinicians. These cases emphasize the burden of metronidazole resistance in our population. Herein we describe two cases of metronidazole-resistant trichomoniasis. In one case, a patient underwent five courses of therapy to treat a persistent Trichomonas vaginalis infection. International culture and susceptibility testing revealed resistance to metronidazole and susceptibility to tinidazole. The patient was subsequently lost to follow-up. In another case, a patient was treated with six courses of therapy before their infection had cleared. International culture and susceptibility testing indicated resistance to metronidazole and intermediate resistance to tinidazole. In both cases, metronidazole treatment, either alone or in addition to another therapy, was attempted an average of 3.5 times in escalating dose regimens before switching to tinidazole. Tinidazole proved to be an effective second-line therapy when tolerated by the patient. Until susceptibility testing is available in Canada, clinicians should be aware of access to international susceptibility testing of T. vaginalis to appropriately identify metronidazole-resistant cases and make timely and informed decisions regarding treatment.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

Recent advances in the epidemiology, diagnosis, and management of Trichomonas vaginalis infection

Trichomonas vaginalis is the most common, curable non-viral sexually transmitted infection (STI) worldwide. Despite this burden of disease, it is not currently a reportable disease in the United States. Recent advances in the epidemiology, diagnosis, and management of T. vaginalis infection are described in this article. This includes updated global and U.S. prevalence data in women and men as well as recent epidemiological data in HIV-infected individuals and pregnant women. Advances in molecular diagnostics are also reviewed, as are data from recent clinical trials regarding the treatment of trichomonas in women.

Prevalence and cervical organism burden among Louisiana women with Trichomonas vaginalis infections

Trichomonas vaginalis is the most common curable sexually transmitted infection (STI) worldwide. Although predominately asymptomatic, the disease spectrum of trichomoniasis in women is characterized primarily by signs and symptoms of vaginitis, including purulent discharge and localized vulvar pruritus and erythema. Several FDA-cleared nucleic acid amplification tests (NAATs) are available for the diagnosis of T. vaginalis infections, but laboratory developed tests (LDTs) are widely utilized and cost-effective solutions in both the research and clinical diagnostic settings. LDT diagnosis of T. vaginalis is particularly appealing since it can be performed using remnant specimens collected for other STI testing. Using a LDT implemented as part of this study, T. vaginalis was detected in 7% of participating Louisiana women (14/199). The mean T. vaginalis organism burden was 1.0x10⁶ ± 4.5x10⁵ organisms per mL of ThinPrep PreservCyt. Using DNA eluates obtained after HPV testing on the cobas 4800 system, the T. vaginalis LDT was characterized by excellent intra- and interassay reproducibility (coefficient of variation values all <3.5%). Compared with two commercially available NAATs from TIB MOLBIOL, the sensitivity and specificity of the LDT was 92.9 and 99.5%, respectively. Collectively, this study details the diagnostic and quantitative utility of a LDT for T. vaginalis. When applied in the clinical research setting, we confirmed the high prevalence of T. vaginalis, but also observed extraordinarily high organism burdens in the cervix. These findings highlight the unique host-pathogen relationship of T. vaginalis with lower reproductive tract tissues, and substantiate the need for continued investigation of this highly prevalent STI.

Chlorinated metronidazole as a promising alternative for treating trichomoniasis

Trichomoniasis is the most common non-viral, sexually transmitted infection affecting humans worldwide. The main treatment for trichomoniasis is metronidazole (MTZ). However, adverse effects and reports of resistance have stimulated the development of therapeutic alternatives. The ease of manipulation of the side chains of MTZ coupled with its safety makes this molecule attractive for the development of new drugs. In this context, we evaluated the activity of the chlorinated MTZ derivative, MTZ-Cl, on sensitive and resistant strains of Trichomonas vaginalis. MTZ-Cl presented a remarkable activity against both sensitive and resistant strains. In vitro and in vivo toxicity assays indicated that the new molecule is safe for future clinical trials. Furthermore, we noticed different rates of free radical production between the sensitive and resistant strains. MTZ-Cl induced a higher release of nitric oxide (NO, ~ 9000 a.u.) by both sensitive and resistant strains. However, the sensitive strain produced a greater amount of H₂O₂ (~ 1,800,000 a.u.) and superoxide radicals (~ 350,000 a.u.) in the presence of MTZ. In the resistant strain, production of these radicals was more prominent when MTZ-Cl was used. Collectively, these results suggest that NO is an important molecule in the trichomonacidal activity against resistant and sensitive strains, suggesting an alternative pathway for MTZ-Cl activation. We highlight the high trichomonacidal potential of MTZ-Cl, improving the effectiveness of treatment and reducing side effects. In addition, MTZ-Cl is derived from a well-established drug on the world market that presents low toxicity to human cells, suggesting its safety to proceed with future clinical trials.

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

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

Primary health clinic toilet/bathroom surface swab sampling can indicate community profile of sexually transmitted infections

BACKGROUND

The microbiome of built environment surfaces is impacted by the presence of humans. In this study, we tested the hypothesis that analysis of surface swabs from clinic toilet/bathroom yields results correlated with sexually transmitted infection (STI) notifications from corresponding human populations. We extended a previously reported study in which surfaces in toilet/bathroom facilities in primary health clinics in the Australian Northern Territory (NT) were swabbed then tested for nucleic acid from the STI agents Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis. This was in the context of assessing the potential for such nucleic acid to contaminate specimens collected in such facilities. STIs are notifiable in the NT, thus allowing comparison of swab and notification data.

METHODS

An assumption in the design was that while absolute built environment loads of STI nucleic acids will be a function of patient traffic density and facility cleaning protocols, the relative loads of STI nucleic acids from different species will be largely unaffected by these processes. Another assumption was that the proportion of swabs testing positive for STIs provides a measure of surface contamination. Accordingly, "STI profiles" were calculated. These were the proportions that each of the three STIs of interest contributed to the summed STI positive swabs or notifications. Three comparisons were performed, using swab data from clinics in remote Indigenous communities, clinics in small-medium towns, and a single urban sexual health clinic. These data were compared with time and place-matched STI notifications.

RESULTS

There were significant correlations between swab and notifications data for the both the remote Indigenous and regional data. For the remote Indigenous clinics the p values ranged from 0.041 to 0.0089, depending on data transformation and p value inference method. Further, the swab data appeared to strongly indicate known higher relative prevalence of gonorrhoeae in central Australia than in northern Australia. Similarly, the regional clinics yielded p values from 0.0088-0.0022. In contrast, swab and notifications data from the sexual health clinic were not correlated.

DISCUSSION

Strong correlations between swab and notifications were observed. However, there was evidence for limitations of this approach. Despite the correlation observed with the regional clinics data, one clinic yielded zero positive swabs for C. trachomatis, although this STI constituted 25.1% of the corresponding notifications. This could be ascribed to stochastic effects. The lack of correlation observed for sexual health clinic data was also likely due to stochastic effects. It was concluded that toilet/bathroom surface swab sampling has considerable potential for public health surveillance. The approach may be applicable in situations other than primary health clinics, and for targets other than STIs.

Trichomoniasis immunity and the involvement of the purinergic signaling

Innate and adaptive immunity play a significant role in trichomoniasis, the most common non-viral sexually transmitted disease worldwide. In the urogenital tract, innate immunity is accomplished by a defense physical barrier constituted by epithelial cells, mucus, and acidic pH. During infection, immune cells, antimicrobial peptides, cytokines, chemokines, and adaptive immunity evolve in the reproductive tract, and a proinflammatory response is generated to eliminate the invading extracellular pathogen Trichomonas vaginalis. However, the parasite has developed complex evolutionary mechanisms to evade the host immune response through cysteine proteases, phenotypic variation, and molecular mimicry. The purinergic system constitutes a signaling cellular net where nucleotides and nucleosides, enzymes, purinoceptors and transporters are involved in almost all cells and tissues signaling pathways, especially in central and autonomic nervous systems, endocrine, respiratory, cardiac, reproductive, and immune systems, during physiological as well as pathological processes. The involvement of the purinergic system in T. vaginalis biology and infection has been demonstrated and this review highlights the participation of this signaling pathway in the parasite immune evasion strategies.

Trichomoniasis - are we giving the deserved attention to the most common non-viral sexually transmitted disease worldwide?

ETIOLOGY

Trichomonas vaginalis is the etiologic agent of trichomoniasis, the most common non-viral sexually transmitted disease (STD) in the world. Transmission: Trichomoniasis is transmitted by sexual intercourse and transmission via fomites is rare. Epidemiology, incidence and prevalence: The WHO estimates an incidence of 276 million new cases each year and prevalence of 187 million of infected individuals. However, the infection is not notifiable. Pathology/Symptomatology: The T. vaginalis infection results in a variety of clinical manifestations - in most cases the patients are asymptomatic, but some may develop signs typically associated to the disease. Importantly, the main issue concerning trichomoniasis is its relationship with serious health consequences such as cancer, adverse pregnancy outcomes, infertility, and HIV acquisition. Molecular mechanisms of infection: To achieve success in parasitism trichomonads develop a complex process against the host cells that includes dependent- and independent-contact mechanisms. This multifactorial pathogenesis includes molecules such as soluble factors, secreted proteinases, adhesins, lipophosphoglycan that culminate in cytoadherence and cytotoxicity against the host cells. Treatment and curability: The treatment with metronidazole or tinidazole is recommended; however, cure failures remain problematic due to noncompliance, reinfection and/or lack of treatment of sexual partners, inaccurate diagnosis, or drug resistance. Therefore, new therapeutic alternatives are urgently needed. Protection: Strategies for protection including sexual behavior, condom usage, and therapy have not contributed to the decrease on disease prevalence, pointing to the need for innovative approaches. Vaccine development has been hampered by the lack of long-lasting humoral immunity associated to the absence of good animal models.

Comparative analysis of syndromic and PCR-based diagnostic assay reveals misdiagnosis/ overtreatment for trichomoniasis based on subjective judgment in symptomatic patients

Background

Trichomoniasis, a sexually transmitted disease (STD), is caused by Trichomonas vaginalis in both men and women. Screening of trichomoniasis is problematic in resource challenged settings as currently available, inexpensive diagnostic methods are of low sensitivity and/or specificity. In India, National AIDS Control organization (NACO) recommended syndromic case management (SCM) for treatment. The objective of the present study was to compare the utility of the NACO-NACP III Algorithms for STI/RTI treatment used by clinicians with PCR based diagnosis.

Methods

Patients visiting Department of Obstetrics & Gynecology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi from January 2011 to June 2014 were enrolled in the study to compare the diagnostic efficiency of PCR-based assays against SCM. Based on SCM, patients (n = 820) were treated with antibiotics using pre-packed STI/RTI kits (sexually transmitted infection/reproductive tract infection; procured by National AIDS Control/State AIDS Control Society (NACO/SACS), Ministry of Health and Family Welfare, Govt of India.) under National AIDS Control Programme (NACP III) for syndromic case management (SCM). Ectocervical dry swab samples were also obtained from these patients and out of that 634 samples were tested by PCR. Total genomic DNA was extracted from these samples and used as template for PCR amplification using pfoB, gyrA and orf1 gene specific primers for diagnosis of T. vaginalis (TV), Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) respectively.

Results

Out of 6000 patients who visited OPD, 820 (14 %) female patients reported vaginal discharge and were recommended antibiotic treatment for one or more pathogens namely, TV, CT, NG and Candida or for co-infection. On the basis of signs & symptoms and NACO guidelines, the following distribution of various infections was observed: TV (46 %), CT (20 %), coinfection with TV and CT (12 %), coinfection with CT and NG (11 %), coinfection with TV, CT and Candida (7 %) and coinfection with TV and NG (2 %). Others were infected with NG alone (1 %), coinfected with TV and Candida (0.4 %) and 0.3 % were coinfected with CT, NG and Candida. Based on PCR method, 110 (17 %) women tested positive for one or more of these three pathogens while 524 (83 %) women were negative for any of these three pathogens but could be positive for other STIs not tested in this study. Since all the patients (634) were given antibiotics, we estimate that the over-treatment was 85 % while 524 (83 %) patients were also misdiagnosed by SCM.

Conclusions

The over-treatment and inaccurate diagnosis of pathogens due to subjective judgment based on syndromic approach in symptomatic women is a large economic wastage and may also contribute towards increased resistance. The misdiagnosed patients will also serve as a reservoir for transmission of pathogens to their sexual partner.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-016-0133-x) contains supplementary material, which is available to authorized users.

Opportunities and pitfalls of molecular testing for detecting sexually transmitted pathogens

In the last 20 years, nucleic acid amplification tests (NAATs) have gradually replaced traditional methods for the detection of sexually transmitted infections. NAAT technology comes with some considerable benefits for diagnosis, including increased sensitivity, rapid result turnaround and suitability for high throughput screening of asymptomatic individuals using more-readily available specimens. However, the transition to NAAT has not come without its problems. False-negative and false-positive results have been reported owing to various technical issues. Furthermore, increased reliance on NAATs for diagnosis have created the need to develop NAAT-based methods to inform treatment, being an area that presents its own set of challenges. In this review article, we explore NAAT-based detection of Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium and Trichomonas vaginalis. In doing so, we consider the benefits and limitations of NAAT-based technology and highlight areas where further research and development is in need.

[Non-gonococcal infectious urethritis : pathogen spectrum and management]

For many years an increase in cases of urethritis has been observed in western Europe. In order to be able to combat this continuous rise, the perception of sexually transmitted diseases must be promoted, the clarification and screening must be intensified and therapy must be rapidly and correctly carried out. In addition to the commonest pathogens causing urethritis, namely chlamydia and gonococci, many other pathogenic microbes must be taken into consideration in the diagnostics. With respect to therapy, apart from the increasing resistance formation of Mycoplasma genitalium, the decreasing effectiveness of standard forms of treatment of other microbes must be emphasized. For chronic and recurrent urethritis in particular a broad clarification of the pathogen should be carried out to enable targeted treatment and also partner treatment. Priority must again be given to primary prevention.

The antimicrobial effect of boric acid on Trichomonas vaginalis

BACKGROUND

The treatment options for trichomoniasis are largely limited to nitroimidazole compounds (metronidazole and tinidazole). Few alternatives exist in cases of recalcitrant infections or in cases of nitroimidazole hypersensitivity. Recently, the intravaginal administration of boric acid has been advocated as an alternative treatment of trichomoniasis. However, no in vitro studies are available that directly assess the sensitivity of Trichomonas vaginalis to boric acid.

METHODS

We examined the sensitivity of common laboratory strains and recent clinical isolates of T. vaginalis to boric acid. The effect of increasing concentrations of boric acid on parasite growth and viability was determined, and a minimal lethal concentration was reported. The effect of pH on boric acid toxicity was assessed and compared with that of lactic and acetic acid.

RESULTS

Boric acid is microbicidal to T. vaginalis, and its antitrichomonal activity is independent of environmental acidification. Unlike acetic acid and lactic acid, boric acid exposure results in growth suppression and lethality over a wide range of pH (5-7) and under conditions that are normally permissible for growth in vitro.

CONCLUSIONS

The microbicidal effect of boric acid on T. vaginalis, coupled with its previous clinical use in treating vaginal candidiasis, supports the continued inclusion of boric acid in the therapeutic arsenal for treating trichomoniasis.

Trichomonas vaginalis origins, molecular pathobiology and clinical considerations

PURPOSE OF REVIEW

To integrate a selection of the most recent data on Trichomonas vaginalis origins, molecular cell biology and T. vaginalis interactions with the urogenital tract microbiota with trichomoniasis symptoms and clinical management.

RECENT FINDINGS

Transcriptomics and proteomics datasets are accumulating, facilitating the identification and prioritization of key target genes to study T. vaginalis pathobiology. Proteins involved in host sensing and cytoskeletal plasticity during T. vaginalis amoeboid transformation were identified. T. vaginalis was shown to secrete exosomes and a macrophage migration inhibitory factor-like protein that both influence host-parasite interactions. T. vaginalis co-infections with Mycoplasma species and viruses were shown to modulate the inflammatory responses, whereas T. vaginalis interactions with various Lactobacillus species inhibit parasite interactions with human cells. T. vaginalis infections were also shown to be associated with bacterial vaginosis. A broader range of health sequelae is also becoming apparent. Diagnostics for both women and men based on the molecular approaches are being refined, in particular for men.

SUMMARY

New developments in the molecular and cellular basis of T. vaginalis pathobiology combined with data on the urogenital tract microbiota and immunology have enriched our knowledge on human-microbe interactions that will contribute to increasing our capacity to prevent and treat T. vaginalis and other sexually transmitted infections.

Large two-centre study into the prevalence of Mycoplasma genitalium and Trichomonas vaginalis in the Netherlands

Mycoplasma genitalium and Trichomonas vaginalis are common sexually transmitted infections (STIs). In the Netherlands, testing for M. genitalium and T. vaginalis is not recommended for first-line STI screening. Recent reports about the increasing antimicrobial resistance in M. genitalium raise concern about the adequacy of current empirical treatment regimens. It is necessary to have insight in the prevalence of M. genitalium and T. vaginalis in order to evaluate current first-line STI screening and treatment protocols. During a five-month period, samples sent to two large medical microbiology diagnostic centres in the Netherlands for STI screening (Chlamydia trachomatis and Neisseria gonorrhoeae) were retrospectively tested for the prevalence of M. genitalium and T. vaginalis using the Diagenode S-DiaMGTV kit. A total of 1569 samples from 1188 unique patients (55.4% female) were tested. M. genitalium was the second most prevalent STI detected (4.5% of the patients), after C. trachomatis (8.3%). T. vaginalis was detected in 1.4% of the patients, comparable to the prevalence of N. gonorrhoeae (1.3%). Dual infections were only detected in a small number of patients (1.0%). Incorporation of M. genitalium into routine STI screening should be considered, because of its relatively high prevalence, the consequences of its detection for antibiotic treatment and because of the availability of easy-to-use molecular diagnostic tests. For T. vaginalis, routine screening may be considered, depending on local prevalence and (sub)population.

Natural and synthetic compound anti-Trichomonas vaginalis: an update review

Trichomonas vaginalis is a flagellate protozoan that causes trichomonosis, a sexually transmitted disease of worldwide importance. However, the infection has long received much less attention than other parasitic and sexually transmitted diseases. This negligence leads to poor diagnosis and underestimated prevalence values, and consequently, it has been associated to increasing acquisition and transmission of HIV, pregnancy outcomes, infertility, pelvic inflammatory disease, and cervical and prostate cancer. In view of increased resistance to drugs belonging to the nitroimidazole class, new treatment alternatives are urgently needed. Natural products provide an immeasurable wealth of active molecules, and a great number of new drugs have been originated from these compounds. In addition, new synthetic products or derivatives from old drugs also provide an alternative to treat trichomonosis. Albeit many studies have been performed with natural products against T. vaginalis, none of them progressed to clinical trials. Overall, inadequate financial investments are made, and no alternative treatment for trichomonosis has been discovered; meanwhile, hundreds of thousands of people will remain infected and suffering the serious consequences of this nonviral STD. Thus, it is highlighted that clinical trials for better understanding the potential in vitro are necessary and urgent in order to furnish a new therapeutic alternative for trichomonosis treatment. The current review attempts to give an overview on the potential of natural and synthetic products as antitrichomonal.

Trichomonas vaginalis as a cause of perinatal morbidity: a systematic review and meta-analysis

Trichomonas vaginalis is the most common curable sexually transmissible infection worldwide, with high rates in women of reproductive age. There have been inconsistent findings about the impact of infection and its treatment in pregnancy. We conducted a meta-analysis to determine the association between T. vaginalis and perinatal outcomes. Electronic databases were searched to May 2013. Included studies reported perinatal outcomes in women infected and uninfected with T. vaginalis. Meta-analysis calculated a pooled relative risk (RR) and 95% confidence interval (CI) using either a fixed- or random-effects model. Study bias was assessed using funnel plots. Of 178 articles identified, 11 studies met the inclusion criteria. The study populations, outcomes, and quality varied. T. vaginalis in pregnancy was associated with an increased risk of preterm birth (RR, 1.42; 95% CI, 1.15-1.75; 9 studies; n = 81,101; I = 62.7%), preterm premature rupture of membranes (RR, 1.41; 95% CI,1.10-1.82; 2 studies; n = 14,843; I = 0.0%) and small for gestational age infants (RR, 1.51; 95% CI,1.32-1.73; 2 studies; n = 14,843; I = 0.0%). Sensitivity analyses of studies that accounted for coinfection with other sexually transmissible infection found a slightly reduced RR of 1.34 for preterm birth (95% CI, 1.19-1.51; 6 studies; n = 72,077; I = 11.2%), and in studies where no treatment was confirmed, the RR was 1.83 (95% CI, 0.98-3.41; 3 studies; n = 1795; I = 22.3%). Our review provides strong evidence that T. vaginalis in pregnancy is associated with an increased risk of preterm birth. Based on fewer studies, there were also substantial increases in the risk of preterm premature rupture of membranes and small for gestational age infants. Further studies that address the current gaps in evidence on treatment effects in pregnancy are needed.

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.

Differential expression of lactic acid isomers, extracellular matrix metalloproteinase inducer, and matrix metalloproteinase-8 in vaginal fluid from women with vaginal disorders

OBJECTIVE

Do metabolites in vaginal samples vary between women with different vaginal disorders.

DESIGN

Cross-sectional study.

SETTING

Campinas, Brazil.

SAMPLE

Seventy-seven women (39.9%) with no vaginal disorder, 52 women (26.9%) with vulvovaginal candidiasis (VVC), 43 women (22.3%) with bacterial vaginosis (BV), and 21 women (10.9%) with cytolytic vaginosis (CTV).

METHOD

Concentrations of D- and L-lactic acid, extracellular matrix metalloproteinase inducer (EMMPRIN), and matrix metalloproteinase-8 (MMP-8), and the influence of Candida albicans on EMMPRIN production by cultured vaginal epithelial cells, were determined by enzyme-linked immunosorbent assay (ELISA). Associations were determined by the Mann-Whitney U-test and by Spearman's rank correlation test.

MAIN OUTCOME MEASURES

Metabolite levels and their correlation with diagnoses.

RESULTS

Vaginal concentrations of D- and L-lactic acid were reduced from control levels in BV (P < 0.0001); L-lactic acid levels were elevated in CTV (P = 0.0116). EMMPRIN and MMP-8 concentrations were elevated in VVC (P < 0.0001). EMMPRIN and L-lactic acid concentrations (P ≤ 0.008), but not EMMPRIN and D-lactic acid, were correlated in all groups. EMMPRIN also increased in proportion with the ratio of L- to D-lactic acid in controls and in women with BV (P ≤ 0.009). Concentrations of EMMPRIN and MMP-8 were correlated in controls and women with VVC (P ≤ 0.0002). Candida albicans induced EMMPRIN release from vaginal epithelial cells.

CONCLUSIONS

Vaginal secretions from women with BV are deficient in D- and L-lactic acid, women with VVC have elevated EMMPRIN and MMP-8 levels, and women with CTV have elevated L-lactic acid levels. These deviations may contribute to the clinical signs, symptoms, and sequelae that are characteristic of these disorders.

Multidrug resistance: an emerging crisis

The resistance among various microbial species (infectious agents) to different antimicrobial drugs has emerged as a cause of public health threat all over the world at a terrifying rate. Due to the pacing advent of new resistance mechanisms and decrease in efficiency of treating common infectious diseases, it results in failure of microbial response to standard treatment, leading to prolonged illness, higher expenditures for health care, and an immense risk of death. Almost all the capable infecting agents (e.g., bacteria, fungi, virus, and parasite) have employed high levels of multidrug resistance (MDR) with enhanced morbidity and mortality; thus, they are referred to as “super bugs.” Although the development of MDR is a natural phenomenon, the inappropriate use of antimicrobial drugs, inadequate sanitary conditions, inappropriate food-handling, and poor infection prevention and control practices contribute to emergence of and encourage the further spread of MDR. Considering the significance of MDR, this paper, emphasizes the problems associated with MDR and the need to understand its significance and mechanisms to combat microbial infections.

Development of a loop-mediated isothermal amplification assay for detection of Trichomonas vaginalis

A loop-mediated isothermal amplification (LAMP) assay targeting the 2-kbp repeated DNA species-specific sequence was developed for detection of Trichomonas vaginalis, the causative agent of trichomoniasis. The analytical sensitivity and specificity of the LAMP assay were evaluated using pooled genital swab and urine specimens, respectively, spiked with T. vaginalis trophozoites. Genital secretion and urine did not inhibit the detection of the parasite. The sensitivity of the LAMP was 10-1000 times higher than the PCR performed. The detection limit of LAMP was 1 trichomonad for both spiked genital swab and urine specimens. Also, LAMP did not exhibit cross-reactivity with closely-related trichomonads, Trichomonas tenax and Pentatrichomonas hominis, and other enteric and urogenital microorganisms, Entamoeba histolytica, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. This is the first report of a LAMP assay for the detection of T. vaginalis and has prospective application for rapid diagnosis and control of trichomoniasis.

Detection of Trichomonas vaginalis DNA by use of self-obtained vaginal swabs with the BD ProbeTec Qx assay on the BD Viper system

Trichomonas vaginalis is the most prevalent nonviral sexually transmitted infection worldwide, and improved diagnostic methods are critical for controlling this pathogen. Diagnostic assays that can be used in conjunction with routine chlamydia/gonorrhea nucleic acid-based screening are likely to have the most impact on disease control. Here we describe the performance of the new BD T. vaginalis Qx (TVQ) amplified DNA assay, which can be performed on the automated BD Viper system. We focus on data from vaginal swab samples, since this is the specimen type routinely used for traditional trichomonas testing and the recommended specimen type for chlamydia/gonorrhea screening. Vaginal swabs were obtained from women attending sexually transmitted disease or family planning clinics at 7 sites. Patient-collected vaginal swabs were tested by the TVQ assay, and the Aptima T. vaginalis (ATV) assay was performed using clinician-collected vaginal swabs. Additional clinician-collected vaginal swabs were used for the wet mount and culture methods. Analyses included comparisons versus the patient infection status (PIS) defined by positive results with the wet mount method or culture, direct comparisons assessed with κ scores, and latent class analysis (LCA) as an unbiased estimator of test accuracy. Data from 838 women, 116 of whom were infected with T. vaginalis, were analyzed. The TVQ assay sensitivity and specificity estimates based on the PIS were 98.3% and 99.0%, respectively. The TVQ assay was similar to the ATV assay (κ=0.938) in direct analysis. LCA estimated the TVQ sensitivity and specificity as 98.3 and 99.6%, respectively. The TVQ assay performed well using self-collected vaginal swabs, the optimal sample type, as recommended by the CDC for chlamydia/gonorrhea screening among women.