Efficacy of Rifaximin Vaginal Tablets in Treatment of Bacterial Vaginosis: a Molecular Characterization of the Vaginal Microbiota

Abstract

<jats:title>ABSTRACT</jats:title><jats:p>Bacterial vaginosis (BV) is a common vaginal disorder characterized by an alteration of the vaginal bacterial morphotypes, associated with sexually transmitted infections and adverse pregnancy outcomes. The purpose of the present study was to evaluate the impact of different doses of rifaximin vaginal tablets (100 mg/day for 5 days, 25 mg/day for 5 days, and 100 mg/day for 2 days) on the vaginal microbiota of 102 European patients with BV enrolled in a multicenter, double-blind, randomized, placebo-controlled study. An integrated molecular approach based on quantitative PCR (qPCR) and PCR-denaturing gradient gel electrophoresis (PCR-DGGE) was used to investigate the effects of vaginal tablets containing the antibiotic. An increase in members of the genus<jats:named-content xmlns:xlink="http://www.w3.org/1999/xlink" content-type="genus-species" xlink:type="simple">Lactobacillus</jats:named-content>and a decrease in the BV-related bacterial groups after the antibiotic treatment were demonstrated by qPCR. PCR-DGGE profiles confirmed the capability of rifaximin to modulate the composition of the vaginal microbial communities and to reduce their complexity. This molecular analysis supported the clinical observation that rifaximin at 25 mg/day for 5 days represents an effective treatment to be used in future pivotal studies for the treatment of BV.</jats:p>

Rifaximin Modulates the Vaginal Microbiome and Metabolome in Women Affected by Bacterial Vaginosis

“…The major differences from ineffective treatment were induced by 25 mg of rifaximin for 5 days, in agreement with the findings of Cruciani et al (12), who described this dosage as the best treatment regimen in terms of restoration of a healthy-like microbiota.…”

“…Demographic characteristics and sexual habits of these patients are reported in Table 1. The patients had previously been enrolled in a multicenter, double-blind, randomized, placebo-controlled study (EudraCT;2009-011826-32) performed to compare the efficacy of rifaximin vaginal tablets to that of the placebo for the treatment of BV (11,12). Diagnosis of BV was made using both Amsel's criteria and Nugent score at the screening visit (V1).…”

“…In common with the structural analogue rifampin and other members of the rifamycin class, it acts on the ␤ subunit of the bacterial RNA polymerase to inhibit RNA synthesis (9,10). Recently, the efficacy of rifaximin vaginal tablets in the treatment of BV was demonstrated by evaluating the rate of clinical remission (11) and the restoration of normal vaginal communities (12) and proteome profiles (13).…”

Development of a Microarray-Based Tool To Characterize Vaginal Bacterial Fluctuations and Application to a Novel Antibiotic Treatment for Bacterial Vaginosis

“…Total bacterial DNA was extracted from vaginal rinsings by using a DNeasy blood and tissue kit (Qiagen) as previously described (18).…”

“…The analysis of the clinical parameters (17), the molecular composition of vaginal communities (18), and the proteomic and metabolic profiles of vaginal fluids (19,20) revealed that treatment with 25 mg of rifaximin for 5 days can effectively counteract the alterations associated with the BV condition.…”