In Vitro Activity of Nifuratel on Vaginal Bacteria: Could It Be a Good Candidate for the Treatment of Bacterial Vaginosis?

Abstract

Bacterial vaginosis is characterized by a shift of the physiological flora to a diverse spectrum of bacteria, where Gardnerella vaginalis and Atopobium vaginae are the most important markers. In this study, the antimicrobial activity of nifuratel against G. vaginalis, A. vaginae, and lactobacilli was compared with that of the two currently used antibiotics metronidazole and clindamycin. Results suggest that nifuratel has a better spectrum of activity, being highly active against G. vaginalis and A. vaginae without affecting lactobacilli.The microbial flora of the vagina contains high concentrations of a composite population of bacteria (11,21). It is dominated mainly by lactobacilli that maintain an acidic pH by H 2 O 2 and lactic acid production (14). Alterations in this ecosystem can lead to bacterial vaginosis (BV) and Candida vaginitis, which account for 90% of vaginal infections (10).BV is a polymicrobial syndrome characterized by alteration of the vaginal flora, where the normally occurring Lactobacillus species are overgrown by endogenous bacteria (24). In particular, high concentrations of Gardnerella vaginalis and Atopobium vaginae have been shown to be important microbiological markers (1,18,27). The association between the presence of A. vaginae and BV has been highlighted only recently (8), thanks to its detection by molecular techniques. Although its exact role is not yet fully understood, the association between A. vaginae and BV is well established (1,17,18,27), as is its involvement, together with G. vaginalis, in the biofilm present on the vaginal epithelium during BV (25).The therapies of choice for BV are systemic or topical metronidazole and clindamycin. Previous studies reported cure rates of 70 to 96% for both antibiotics, with recurrence rates of 49 to 66%, following 7 days of therapy (2, 13, 16).Inadequate diagnosis (23), pharmacologic resistance (20), and persistence of an adherent bacterial biofilm after treatment (26) seem to be the main reasons for failures of BV treatment and eradication, as well as the presence of a complex microbial population with putative resistance to antimicrobials.Nifuratel is a nitrofuran derivative with strong activity against Trichomonas vaginalis (4, 7) and a broad spectrum of antibacterial action (7,19,22). The purpose of this study was to investigate the potential of nifuratel in the treatment of BV and compare it with metronidazole and clindamycin against G. vaginalis, A. vaginae, and lactobacilli.The bacterial strains tested were both clinical isolates and reference strains. Clinical isolates from vaginal swabs (provided by Maditest, Vevey, Switzerland) were grown and identified following standard protocols. In addition, Lactobacillus strains were identified by DNA amplification and sequencing Stock solutions of nifuratel (Polichem, Lugano-Pazzallo, Switzerland) and metronidazole (Sigma-Aldrich, Munich, Germany) were prepared in dimethyl sulfoxide (DMSO; SigmaAldrich) to a concentration of 51.2 mg/ml. Clindamycin (SigmaAldrich) was dissolved in water t...

Multiplex PCR detection of problematic pathogens of clinically heterogeneous bacterial vaginosis in Bulgarian women

“…Only nifuratel and rifaximin have shown strong in vitro activity against the resistant and problematic etiological agents A. vaginae, G. vaginalis, and Mobiluncus spp. without nonbeneficial effects on lactobacilli (12,33,34). New studies have presented data that demonstrate that the known antibiotic therapy alone is not a viable option for the eradication of the BV-related bacteria in biofilm; rather, combinations of antimicrobial drugs, disinfectants, and probiotics are more useful (18,(35)(36)(37)(38).…”

The Addition of Vitamin C Vaginal Tablets to Oral Metronidazole and its Effect on the Treatment and Recurrence of Bacterial Vaginosis: A Randomized Triple-Blind Clinical Trial

“…Anaerobic bacteria will not be able to grow within pH 3.8-4.5 (28). Use of antibiotics for BV treatment would lead to anaerobic bacteria resistance, treatment failure, and recurrence of BV within a few weeks (30). Use of vitamin C vaginal, as an extra treatment plays an important role in keeping down the pH.…”

Current views on vaginal microbiota and its impact on pregnancy outcomes

“…Клиндамицин имеет более широкий, по сравнению с метронидазолом, спектр анти-бактериальной активности. При исследовании реактивности клиндамицина в отношении основ ных ассоциированных с БВ бактерий была продемонстрирована их высокая чувстви-тельность к данному препарату [57]. Показано, что не все штаммы A. vaginae резистентны к ме-тронидазолу.…”

“…Показано, что не все штаммы A. vaginae резистентны к ме-тронидазолу. G. Togni et al (2011) исследовали чувствительность A. vaginae к метронидазолу и клиндамицину и установили, что чувстви-тельность к метронидазолу существенно варьи-ровала, в то время как клиндамицин ингибиро-вал рост всех исследуемых штаммов в низких концентрациях [57].…”