Bacterial vaginosis, Atopobium vaginae and nifuratel

Abstract

As bacterial vaginosis (BV) is a potential cause of obstetric complications and gynecological disorders, there is substantial interest in establishing the most effective treatment. Standard treatment - metronidazole or clindamycin, by either vaginal or oral route � is followed by relapses in about 30% of cases, within a month from treatment completion. This inability to prevent recurrences reflects our lack of knowledge on the origins of BV. Atopobium vaginae has been recently reported to be associated with BV in around 80% of the cases and might be involved in the therapeutic failures. This review looks at the potential benefits of nifuratel against A. vaginae compared to the standard treatments with metronidazole and clindamycin. In vitro, nifuratel is able to inhibit the growth of A. vaginae, with a MIC range of 0.125-1 μg/mL; it is active against G. vaginalis and does not affect lactobacilli. Metronidazole is active against A. vaginae only at very high concentrations (8-256 μg/mL); it is partially active against G. vaginalis and also has no effect on lactobacilli. Clindamycin acts against A. vaginae with an MIC lower than 0.125 μg/mL and is active on G. vaginalis but it also affects lactobacilli, altering the vaginal environment. These observations suggest that nifuratel is probably the most valid therapeutic agent for BV treatment.

Fig. (1)

A) Grey-white colonies of A. vaginae after 48h culture in anaerobic conditions. B) Gram staining shows Gram-positive bacteria, with A. vaginae visible as single cells, in pairs or short chains. Geissdorfer et al. 2003 [41].

Fig. (2)

These microscopy images (A,B,C) show an unbroken Gardnerella vaginalis biofilm completely coating the vaginal epithelium. The lower panels show the same microscopic field (Ca) in dark-red fluorescence and (Cb) in orange fluorescence. Lactobacilli, interwoven with G. vaginalis in the film, only account for 5% of the bacterial population. Swidsinki et al. 2005 [7].

Fig. (3)

Microscopic images of the biofilm during and after treatment with metronidazole. A) Bacterial biofilm (x 400) in a patient at the third day of metronidazole therapy. The film is thin. B) Bacterial biofilm (x 400) in the same patient on day 35. The film has reformed almost completely. Swidsinki et al. 2008 [9].

Fig. (4)

Activity of nifuratel, metronidazole and clindamycin on lactobacilli, Gardnerella vaginalis and Atopobium vaginae.