Secnidazole: next-generation antimicrobial agent for bacterial vaginosis treatment

Novel 4-nitroimidazole analogues: synthesis, in vitro biological evaluation, in silico studies, and molecular dynamics simulation

A new series of 4-nitroimidazole bearing aryl piperazines 7-16, tetrazole 17 and 1,3,4-thiadiazole 18 derivatives was synthesized. All derivatives were screened for their anticancer activity against eight diverse human cancer cell lines (Capan-1, HCT-116, LN229, NCI-H460, DND-41, HL-60, K562, and Z138). Compound 17 proved the most potent compound of the series inhibiting proliferation of most of the selected human cancer cell lines with IC50 values in the low micromolar range. In addition, compound 11 exhibited IC50 values ranging 8.60-64.0 μM against a selection of cancer cell lines. These findings suggest that derivative 17 can potentially be a new lead compound for further development of novel antiproliferative agents. Additionally, 17-18 were assessed for their antibacterial and antituberculosis activity. Derivatives 17 and 18 were the most potent compounds of this series against both Staphylococcus aureus strain Wichita and a methicillin resistant strain of S. aureus (MRSA), as well as against Mycobacterium tuberculosis strain mc26230. The antiviral activity of 7-18 was also evaluated against diverse viruses, but no activity was detected. The docking study of compound 17 with putative protein targets in acute myeloid leukemia had been studied. Furthermore, the molecular dynamics simulation of 17 and 18 had been investigated.

Prodrugs as empowering tools in drug discovery and development: recent strategic applications of drug delivery solutions to mitigate challenges associated with lead compounds and drug candidates

The delivery of a drug to a specific organ or tissue at an efficacious concentration is the pharmacokinetic (PK) hallmark of promoting effective pharmacological action at a target site with an acceptable safety profile. Sub-optimal pharmaceutical or ADME profiles of drug candidates, which can often be a function of inherently poor physicochemical properties, pose significant challenges to drug discovery and development teams and may contribute to high compound attrition rates. Medicinal chemists have exploited prodrugs as an informed strategy to productively enhance the profiles of new chemical entities by optimizing the physicochemical, biopharmaceutical, and pharmacokinetic properties as well as selectively delivering a molecule to the site of action as a means of addressing a range of limitations. While discovery scientists have traditionally employed prodrugs to improve solubility and membrane permeability, the growing sophistication of prodrug technologies has enabled a significant expansion of their scope and applications as an empowering tool to mitigate a broad range of drug delivery challenges. Prodrugs have emerged as successful solutions to resolve non-linear exposure, inadequate exposure to support toxicological studies, pH-dependent absorption, high pill burden, formulation challenges, lack of feasibility of developing solid and liquid dosage forms, first-pass metabolism, high dosing frequency translating to reduced patient compliance and poor site-specific drug delivery. During the period 2012-2022, the US Food and Drug Administration (FDA) approved 50 prodrugs, which amounts to 13% of approved small molecule drugs, reflecting both the importance and success of implementing prodrug approaches in the pursuit of developing safe and effective drugs to address unmet medical needs.

Development of an anti-infective urinary catheter composed of polyvinyl alcohol/sodium alginate/methylcellulose/polyethylene glycol by using a pressure-assisted 3D-printing technique

Catheter-associated urinary tract infections (CAUTI) are a common complication associated with catheterization, leading to urosepsis, bacteriuria, and septicaemia. The present work focuses on 3D printing a urinary catheter with anti-infective properties using various concentrations of polyvinyl alcohol (PVA, e.g., 6-8 %), sodium alginate (NaAlg, e.g. 1-4 %), methylcellulose (MC, 5 %), polyethylene glycol (PEG, 5 %) impregnated with secnidazole, an antibiotic acting against Gram-negative bacteria. To produce suitable polymer ink for Pressure Assisted Microsyringe (PAM) 3D printing, the cross-linked between NaAlg and calcium chloride is necessary to prepare the catheter. The optimised catheter was found to have an outer diameter of 5 mm, an inner diameter of 3.5 mm, and a length of the catheter of 50 mm. The analysis by various methods confirms the successful incorporation of secnidazole in the 3D-printed catheter. A drug-loaded/coated catheter showed an initial drug release of 79 % following a sustained release to reach 100 % within 5 h. Weibull model fits well with the drug release data. The release models suggest the Quasi-Fickian diffusion mechanism from the system. Moreover, the secnidazole 3D printed catheter disrupted biofilms and suppressed all the Quorum sensing mediated virulence factors of two important keystone pathogens causing urinary tract infections.

Physicochemical considerations in the formulation development of silicone elastomer vaginal rings releasing 5-nitroimidazole drugs for the treatment of bacterial vaginosis

Bacterial vaginosis (BV) is a common dysbiosis of the human vaginal microbiota characterized by depletion of hydrogen peroxide and lactic acid-producing Lactobacillus bacteria and an overgrowth of certain facultative anaerobic bacteria. Although short-term cure rates following treatment with frontline antibiotics (most notably oral metronidazole (MNZ), clindamycin vaginal cream, and MNZ vaginal gel) are generally high, longer-term recurrence rates are an issue. The development of vaginal formulations offering continuous/sustained administration of antibiotic drugs over one or more weeks might prove useful in reducing recurrence. Here, we report the manufacture and preclinical testing of matrix-type vaginal rings offering sustained release of four 5-nitroimidazole antimicrobial drugs either being used clinically or having potential in treatment of BV - MNZ, tinidazole (TNZ), secnidazole (SNZ) and ornidazole (ONZ). All four drugs showed good compatibility with a medical-grade addition-cure silicone elastomer based upon thermal analysis experiments, and matrix-type rings containing 250 mg (3.125 %w/w) of each drug were successfully manufactured by reaction injection molding. 28-day in vitro drug release studies demonstrated root-time kinetics, with daily release rates of 25, 22, 9 and 6 mg/day½ for SNZ, ONZ, MNZ and TNZ, respectively. The rank order of drug release from rings correlated with the simple molecular permeability parameter S/V, where S is the measured drug solubility in silicone fluid and V is the drug molecular volume. The relative merits of SNZ and ONZ over MNZ (the current reference treatment) are discussed. The data support development of vaginal rings for sustained release of 5-nitroimidazole compounds for treatment of BV.

Identification of Trichomonas vaginalis 5-Nitroimidazole Resistance Targets

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

Secnidazole: a treatment for trichomoniasis in adolescents and adults

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

British Association for Sexual Health and HIV (BASHH) United Kingdom national guideline on the management of Trichomonas vaginalis 2021

The main objective of this guideline is to assist practitioners in managing individuals diagnosed with Trichomonas vaginalis (TV). It offers recommendations on the diagnostic tests, treatment regimens and health promotion principles needed for the effective management of TV. It covers the management of the initial presentation, as well as how to prevent transmission and future re-infection. It is aimed primarily at people aged 16 years or older presenting to health care professionals, working in departments offering specialist care in sexually transmitted infection (STI) management within the United Kingdom. However, the principles of the recommendations are applicable across all levels of STI care providers (N.B. non-specialist services may need to develop, where appropriate, local care pathways).

Diagnosis and Management of Trichomonas vaginalis: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines

Trichomonas vaginalis is likely the most prevalent nonviral sexually transmitted infection, affecting an estimated 3.7 million women and men in the United States. Health disparities are prominent in the epidemiology of trichomoniasis, as African Americans are >4 times more likely to be infected than persons of other races. Since publication of the 2015 Centers for Disease Control and Prevention sexually transmitted diseases treatment guidelines, additional data have bolstered the importance of T. vaginalis infection sequelae in women, including increased risk of human immunodeficiency virus (HIV) acquisition, cervical cancer, preterm birth, and other adverse pregnancy outcomes. Less is known about the clinical significance of infection in men. Newly available diagnostic methods, including point-of-care assays and multiple nucleic acid amplification tests, can be performed on a variety of genital specimens in women and men, including urine, allowing more accurate and convenient testing and screening of those at risk for infection. Repeat and persistent infections are common in women; thus, rescreening at 3 months after treatment is recommended. In vitro antibiotic resistance to 5-nitroimidazole in T. vaginalis remains low (4.3%) but should be monitored. High rates of T. vaginalis among sexual partners of infected persons suggest a role for expedited partner treatment. A randomized controlled trial in HIV-uninfected women demonstrated that multidose metronidazole 500 mg twice daily for 7 days reduced the proportion of women with Trichomonas infection at 1 month test of cure compared with women receiving single-dose therapy (2 g). The 2-g single-dose oral metronidazole regimen remains the preferred treatment in men.

Secnidazole for Trichomoniasis in Women and Men

INTRODUCTION

Secnidazole (SEC), newly FDA-approved for trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various infections. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other approved treatments for trichomoniasis in the U.S.-metronidazole and tinidazole-SEC has favorable pharmacokinetics, including a longer half-life, and a lower minimal lethal concentration against Trichomonas vaginalis.

OBJECTIVES

Provide an updated, comprehensive review of the literature evaluating SEC as a treatment for trichomoniasis in women and men.

METHODS

We conducted a search to identify existing research on SEC and trichomoniasis. On August 6, 2021, we searched MEDLINE using the terms "secnidazole" and "trichomon.*" We excluded reviews, editorials, case reports, and small case series.

RESULTS

We identified 29 articles; 14 of which were included: 5 reported in vitro pharmacologic data on SEC, 6 were observational studies, and 4 were controlled clinical trials (1 observational study also reported in vitro pharmacologic data). Six studies reported data on women only, 1 on men only, and 3 on women and men. These studies showed that SEC-as a single dose or 3-day course-had comparable efficacy to multi-dose metronidazole for treating trichomoniasis in women and men, was generally well tolerated by patients, and had a favorable pharmacokinetic profile. A single 2-g dose of SEC also led to a microbiologic cure rate of 92.2% in the first randomized, double-blind, placebo-controlled study of trichomonas-infected US-based women.

CONCLUSION

SEC is an efficacious and safe treatment for women and men with trichomoniasis. Single-dose administration makes it a favorable treatment option for patients, especially in cases where adherence to other multi-dose treatment regimens could be problematic. Christina A. Muzny and Olivia T. Van Gerwen. Secnidazole for Trichomoniasis in Women and Men. Sex Med Rev 2022;10:255-262.

A Comparison of Single-Dose Versus Multidose Metronidazole by Select Clinical Factors for the Treatment of Trichomonas vaginalis in Women

BACKGROUND

In a randomized controlled trial of 2 g (single-dose) metronidazole (MTZ) versus 500 mg twice daily for 7 days (multidose) for Trichomonas vaginalis treatment, multidose was superior. We examined if the effect was similar by select clinical factors to determine if treatment recommendations could be targeted.

METHODS

The primary outcome was T. vaginalis repeat infection at test-of-cure (TOC) 4 weeks after completion of therapy. Analyses were stratified by T. vaginalis history, baseline genital symptoms, and concurrent diagnosis of bacterial vaginosis (BV) per Nugent score at baseline.

RESULTS

Women who returned for TOC (n = 540) were included. At baseline, 52.9% had a self-reported history of T. vaginalis; 79.3%, genital symptoms; 5.8%, a gonorrhea diagnosis; and 47.5%, BV. During follow-up, 97.4% took all MTZ as instructed and 34.5% had interval condomless sex with a baseline partner. At TOC, 14.8% tested positive for T. vaginalis. In stratified analysis, women randomized to single-dose MTZ had a higher rate of TOC T. vaginalis positivity than those randomized to multidose if they were symptomatic at baseline (21.4% vs. 10.8%, P = 0.003) or had a reported history of T. vaginalis (24.1% vs. 12.6%, P = 0.01). Test-of-cure T. vaginalis positivity was higher for women receiving a single dose (18.9%) versus multidose (10.8%), irrespective of baseline BV status (P > 0.06). In multivariable analysis, only a history of T. vaginalis and single-dose MTZ were independently associated with a positive TOC for T. vaginalis.

CONCLUSIONS

Although multidose MTZ is recommended for all women with T. vaginalis, it is especially important for women with a T. vaginalis history and, given high posttreatment infection rates, a TOC should be performed.

Biology-oriented drug synthesis and evaluation of secnidazole esters as novel enzyme ınhibitors

The identification of novel compounds that can inhibit physiologically and metabolically important drug targets or enzymes has prime importance in medicinal chemistry. With this aim, a range of secnidazole esters 1-30 were synthesized under the heading of biology-oriented drug synthesis by the 1,1'-carbonyldiimidazole-mediated coupling reaction between secnidazole and varyingly benzoic acid derivatives. All compounds were screened for inhibitory activity against human carbonic anhydrase (hCA) I and II, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glucosidase. The results indicate that all the synthesized compounds showed potent inhibitory activities against all targets, as compared to the standard inhibitors, revealed by IC₅₀ values. K_i values of the secnidazole derivatives 1-30 for hCA I, hCA II, AChE, BChE, and α-glucosidase enzymes were obtained in the ranges of 47.37-190.74, 44.38-198.21, 12.14-68.37, 8.04-61.53, and 7.78-45.91 nM, respectively. To assess the enzyme-ligand interactions, the optimized most active compounds 2, 3, 8, 9, 14, 17, and 23 were subjected to molecular docking studies with modeled AChE, BChE, hCA I, hCA II, and α-glucosidase enzymes, where several important and key interactions were monitored with amino acid residues of each target enzyme.

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.

Efficacy and Safety of Single Oral Dosing of Secnidazole for Trichomoniasis in Women: Results of a Phase 3, Randomized, Double-Blind, Placebo-Controlled, Delayed-Treatment Study

Background

Trichomonas vaginalis is the most prevalent nonviral sexually transmitted infection. We evaluated the efficacy and safety of secnidazole vs placebo in women with trichomoniasis.

Methods

Women with trichomoniasis, confirmed by a positive T. vaginalis culture, were randomized to single-dose oral secnidazole 2 g or placebo. The primary endpoint was microbiological test of cure (TOC) by culture 6–12 days after dosing. At the TOC visit, participants were given the opposite treatment. They were followed for resolution of infection afterward and offered treatment at subsequent visits, if needed. Fifty patients per group (N = 100) provided approximately 95% power to detect a statistically significant difference between treatment groups.

Results

Between April 2019 and March 2020, 147 women enrolled at 10 sites in the United States. The modified intention-to-treat (mITT) population included 131 randomized patients (secnidazole, n = 64; placebo, n = 67). Cure rates were significantly higher in the secnidazole vs placebo group for the mITT population (92.2% [95% confidence interval {CI}: 82.7%–97.4%] vs 1.5% [95% CI: .0%–8.0%]) and for the per-protocol population (94.9% [95% CI: 85.9%–98.9%] vs 1.7% [95% CI: .0%–8.9%]). Cure rates were 100% (4/4) in women with human immunodeficiency virus (HIV) and 95.2% (20/21) in women with bacterial vaginosis (BV). Secnidazole was generally well tolerated. The most frequently reported treatment-emergent adverse events (TEAEs) were vulvovaginal candidiasis and nausea (each 2.7%). No serious TEAEs were observed.

Conclusions

A single oral 2 g dose of secnidazole was associated with significantly higher microbiological cure rates vs placebo, supporting a role for secnidazole in treating women with trichomoniasis, including those with HIV and/or BV.

Clinical Trials Registration

NCT03935217.

Treatment of Male Sexual Partners of Women With Bacterial Vaginosis: A Randomized, Double-Blind, Placebo-Controlled Trial

BACKGROUND

We aimed to determine if treatment of male sexual partners of women with recurrent bacterial vaginosis (BV) with oral metronidazole 2×/day for 7 days (ie, multidose metronidazole) significantly decreased BV recurrence rates in the female.

METHODS

This was a multicenter, 2-arm, double-blind, placebo-controlled study. Women with recurrent BV and current diagnosis of BV by Amsel and Nugent were enrolled. Multidose metronidazole for 7 days was dispensed to women. Male partners were randomized to placebo versus multidose metronidazole for 7 days and asked to refrain from unprotected sex for 14 days. Female follow-up visits were conducted at day 21 and 8 and 16 weeks. Male follow-up visits occurred at days 14-21. BV cure was defined as 0-2 Amsel criteria and Nugent score 0-6 in the female partner with the primary endpoint at 16 weeks.

RESULTS

214 couples were enrolled. In the intent-to-treat population, there was no significant difference between treatment arms for the primary outcome. BV treatment failure occurred in 81% and 80% of women in the metronidazole and placebo arms through the third follow-up visit, respectively (P > .999). However, women whose male partners adhered to study medication were less likely to fail treatment (adjusted relative risk, .85; 95% CI, .73-.99; P = .035). This finding persisted in post hoc comparisons in the metronidazole arm.

CONCLUSIONS

Overall, this study did not find that male partner treatment with multidose metronidazole significantly reduces BV recurrence in female partners, although women whose partners adhered to multidose metronidazole were less likely to fail treatment.

CLINICAL TRIALS REGISTRATION

(NCT02209519).

The Female Vaginal Microbiome in Health and Bacterial Vaginosis

The vaginal microbiome is an intricate and dynamic microecosystem that constantly undergoes fluctuations during the female menstrual cycle and the woman’s entire life. A healthy vaginal microbiome is dominated by Lactobacillus which produce various antimicrobial compounds. Bacterial vaginosis (BV) is characterized by the loss or sharp decline in the total number of Lactobacillus and a corresponding marked increase in the concentration of anaerobic microbes. BV is a highly prevalent disorder of the vaginal microbiota among women of reproductive age globally. BV is confirmed to be associated with adverse gynecologic and obstetric outcomes, such as sexually transmitted infections, pelvic inflammatory disease, and preterm birth. Gardnerella vaginalis is the most common microorganism identified from BV. It is the predominant microbe in polymicrobial biofilms that could shelter G. vaginalis and other BV-associated microbes from adverse host environments. Many efforts have been made to increase our understanding of the vaginal microbiome in health and BV. Thus, improved novel and accurate diagnosis and therapeutic strategies for BV have been developed. This review covers the features of vaginal microbiome, BV, BV-associated diseases, and various strategies of diagnosis and treatment of BV, with an emphasis on recent research progresses.

Asymptomatic Bacterial Vaginosis: To Treat or Not to Treat?

Purpose of Review

The purpose of this review is to summarize current evidence for and against the treatment of asymptomatic bacterial vaginosis (BV) in women.

Recent Findings

Asymptomatic BV is common although its pathogenesis remains incompletely understood. In favor of treating asymptomatic BV is the large body of data supporting that it is sexually transmitted. Along these lines and similar to other STIs, treatment of BV, regardless of symptom status, should be considered to reduce adverse outcomes of infection (i.e. adverse birth outcomes, infertility, post-gynecologic surgery infections, etc.) and prevent further sexual transmission of BV pathogen(s) to sexual partners. One study has found that treatment of women with asymptomatic BV led to a significant reduction in incident chlamydial infections over a 6 month follow-up period, compared to observation-only women. Additionally, some women with asymptomatic BV actually have symptomatic BV but do not recognize these symptoms as an infection. Nevertheless, limitations of the trial regarding treatment of asymptomatic BV as well as the 2020 United States Preventative Task Force recommendation against screening and treatment of asymptomatic BV in pregnant women dampen enthusiasm for recommending treatment in this setting.

Summary

Treatment of asymptomatic BV remains controversial. Additional studies are needed to further investigate the pathogenesis of BV, which will directly influence advances in its diagnosis, treatment, and prevention.

Probiotic intervention as a potential therapeutic for managing gestational disorders and improving pregnancy outcomes

Recent molecular investigations have significantly developed our knowledge of the characteristics of the reproductive microbiome and their associations with host responses to provide an ideal milieu for the development of the embryo during the peri-implantation period and throughout pregnancy as well as to provide a successful in vitro fertilization and appropriate reproductive outcomes. In this context, the establishment of microbial homeostasis in the female reproductive tract, in various physiological periods, is a substantial challenge, which appears the application of probiotics can facilitate the achievement of this goal. So that, currently, probiotics due to its safe and natural features can be considered as a novel biotherapeutic approach. In this review, we comprehensively discuss the bacterial, fungal, and viral diversity detected in the reproductive tract, and their associations with the establishment of dysbiosis/eubiosis conditions as well as we present the significant outcomes on probiotic intervention as an efficient biotherapeutic strategy for management of gestational disorders and improve pregnancy outcomes.

Bacterial vaginosis: Standard treatments and alternative strategies

Bacterial vaginosis (BV) affects many women and has a high influence on their self-esteem, being associated with huge discomfort and changes in the routines, especially the sexual life. International guidelines recommend the administration of metronidazole, clindamycin or tinidazole orally or intravaginally as the standard treatment. However, the treatment with these antibiotics is associated with high levels of failure and recurrence rates. These may be associated with antibiotic resistance, the inability to eradicate the polymicrobial biofilms, and failure to reestablish acidic pH and the lactobacillus-dominated commensal flora. Therefore, it is emergent to study alternative strategies to replace or to be combined with standard therapies in order to prevent and treat BV more efficiently. Alternative strategies may include antimicrobial substances (other antimicrobials, antiseptics and natural compounds) or substances that aim to reestablish the physiologic vaginal environment (probiotics, prebiotics and acidifying agents) while improving the local immunity response. Besides, the development of formulation strategies and new dosage forms and drug delivery systems can improve treatment efficacy and overcome some limitations associated with conventional products.

High Global Burden and Costs of Bacterial Vaginosis: A Systematic Review and Meta-Analysis

BACKGROUND

Bacterial vaginosis (BV) is the most common vaginal infection among women of reproductive age and is associated with important adverse health outcomes. Estimates of the burden of BV and associated costs are needed to inform research priorities.

METHODS

We conducted a systematic review and meta-analysis of global BV prevalence among reproductive-aged women in the general population. We searched PubMed and Embase and used random effects models to estimate BV prevalence by global regions. We estimated the direct medical costs of treating symptomatic BV. Assuming a causal relationship, we also estimated the potential costs of BV-associated preterm births and human immunodeficiency virus cases in the United States.

RESULTS

General population prevalence of BV is high globally, ranging from 23% to 29% across regions (Europe and Central Asia, 23%; East Asia and Pacific, 24%; Latin America and Caribbean, 24%; Middle East and North Africa, 25%; sub-Saharan Africa, 25%; North America, 27%; South Asia, 29%). Within North America, black and Hispanic women have significantly higher (33% and 31%, respectively) prevalence compared with other racial groups (white, 23%; Asian, 11%; P < 0.01). The estimated annual global economic burden of treating symptomatic BV is US $4.8 (95% confidence interval, $3.7-$6.1) billion. The US economic burden of BV is nearly tripled when including costs of BV-associated preterm births and human immunodeficiency virus cases.

CONCLUSIONS

The BV prevalence is high globally, with a concomitant high economic burden and marked racial disparities in prevalence. Research to determine the etiology of BV and corresponding prevention and sustainable treatment strategies are urgently needed to reduce the burden of BV among women. Additionally, the exceptionally high cost of BV-associated sequelae highlights the need for research to understand potential causal linkages between BV and adverse health outcomes.

Triethylphosphinegold(I) Complexes with Secnidazole-Derived Thiosemicarbazones: Cytotoxic Activity against HCT-116 Colorectal Cancer Cells under Hypoxia Conditions

Triethylphosphinegold(I) complexes [Au(HL1)P(CH₂CH₃)₃]PF₆ (1), [Au(HL2)P(CH₂CH₃)₃]PF₆ (2), and [Au(HL3)P(CH₂CH₃)₃]PF₆ (3) were obtained with (E)-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)hydrazinecarbothioamide (HL1), (E)-N-methyl-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)hydrazinecarbothioamide (HL2), and (E)-2-(1-(2-methyl-5-nitro-1H-imidazol-1-yl)propan-2-ylidene)-N-phenylhydrazinecarbothioamide (HL3). All compounds were assayed for their cytotoxic activities against HCT-116 colorectal carcinoma cells under normoxia and hypoxia conditions and against nonmalignant HEK-293 human embryonic kidney cells under normoxia conditions. The thiosemicarbazone ligands HL1-HL3 were inactive against HCT-116 cells under hypoxia but while HL3 was inactive, HL1 and HL2 proved to be cytotoxic to both cell lineages under normoxia conditions. Complexes (1-3) and the triethylphosphinegod(I) precursor proved to be active against both cell lineages in normoxia as well as in hypoxia. While 1 and 3 revealed to be active against HEK-293 and HCT-116 cells, being approximately as active against HCT-116 cells in normoxia as under hypoxia, complex (2) proved to be more active against HCT-116 cells under hypoxia than under normoxia conditions, and more active against HCT-116 cells than against the nonmalignant HEK-293 cells, with the selectivity index, calculated as SI = IC_50HEK-293/IC_{50HCT-116hypoxia}, equal to 3.7, similar to the value obtained for the control drug tirapazamine (tirapazamine (TPZ), SI = 4). Although the compounds showed distinct cytotoxic activities, the electrochemical behaviors of HL1-HL3 were very similar, as were the behaviors of complexes (1-3). Complex (2) deserves special interest since it was significantly more active under hypoxia than under normoxia conditions. Hence, in this case, selective reduction of the nitro group in a low oxygen pressure environment, resulting in toxic reactive oxygen species (ROS) and damage to DNA or other biomolecules, might operate, while for the remaining compounds, other modes of action probably occur.

Secnidazole for treatment of bacterial vaginosis: a systematic review

Background

Bacterial vaginosis (BV) is one of the common vaginal infections among childbearing women. The usual treatment for BV is metronidazole; hence 30% of women have recurrence within 60 to 90 days after treatment. There are some studies which assessed the effect of secnidazole on BV. The aim of this systematic review was to investigate the effectiveness of secnidazole for treatment of BV.

Methods

The Cochrane Library, MEDLINE (PubMed), Scopus, and Web of Science (all databases from inception till October 28, 2018) were searched. Primary outcomes were clinical cure rate and microbiologic cure rate and the secondary outcomes were adverse events. Data was extracted from eligible studies by two review authors individually and analyzed by RevMan 5.3.

Results

Our search found six trials involving 1528 participants. Treatment with 2 g secnidazole could significantly reduce the risk of BV in patients with three or less episodes of BV in the last year by OR: 7.54 (95% CI, 3.89–14.60, p < 0.00001) and in patients with four or more episodes of BV in the last year (OR: 4.74, 95% CI: 1.51–14.84, p = 0.0.008). Secnidazole (2 g) could significantly increase the microbiologic cure rate in women with 3 or less episodes of BV in the last year (OR: 7.63, 95% CI: 2.30–25.33, p = 0.0009) but not in the women with 4 or more episodes of BV in the last year (OR: 20.17, 95% CI: 1.06–382.45, p = 0.05). The clinical cure rate, microbiological effect and the therapeutic cure rate of 2 g secnidazole was significantly more than that of 1 g secnidazole.

The results showed that the clinical cure rate of 2 g secnidazole was not different from the following medications: metronidazole (500 mg bid for 5 days), secnidazole plus vaginal metronidazole, 2 g single dose of oral metronidazole and 2 g secnidazole plus vaginal ornidazole.

Conclusion

This review showed that 2 g and 1 g secnidazole were better than placebo, however, 2 g secnidazole was more effective than 1 g. Secnidazole 2 g was not different from metronidazole (500 mg bid for 5 days), or from secnidazole plus vaginal metronidazole, or 2 g single dose of oral metronidazole or from 2 g secnidazole plus vaginal ornidazole.

Cervicovaginal microbiota, women's health, and reproductive outcomes

The human microbiome project has shown a remarkable diversity of microbial ecology within the human body. The vaginal microbiota is unique in that in many women it is most often dominated by Lactobacillus species. However, in some women it lacks Lactobacillus spp. and is comprised of a wide array of strict and facultative anaerobes, a state that broadly correlates with increased risk for infection, disease, and poor reproductive and obstetric outcomes. Interestingly, the level of protection against infection can also vary by species and strains of Lactobacillus, and some species although dominant are not always optimal. This factors into the risk of contracting sexually transmitted infections and possibly influences the occurrence of resultant adverse reproductive outcomes such as tubal factor infertility. The composition and function of the vaginal microbiota appear to play an important role in pregnancy and fertility treatment outcomes and future research in this field will shed further translational mechanistic understanding onto the interplay of the vaginal microbiota with women's health and reproduction.