Complexity of vaginal microflora as analyzed by PCR denaturing gradient gel electrophoresis in a patient with recurrent bacterial vaginosis.

OBJECTIVE: Gardnerella vaginalis has long been the most common pathogen associated with bacterial vaginosis (BV). We aimed to test our hypothesis that symptoms and signs of BV do not necessarily indicate colonization by this organism, and often will not respond to standard metronidazole or clindamycin treatment. METHODS: Using a relatively new molecular tool, PCR denaturing gradient gel electrophoresis (DGGE), the vaginal microflora of a woman with recalcitrant signs and symptoms of BV was investigated over a 6-week timeframe. RESULTS: The vagina was colonized by pathogenic enterobacteriaceae, staphylococci and Candida albicans. The detection of the yeast by PCR-DGGE is particularly novel and enhances the ability of this tool to examine the true nature of the vaginal microflora. The patient had not responded to antifungal treatment, antibiotic therapy targeted at anaerobic Gram-negative pathogens such as Gardnerella, nor daily oral probiotic intake of Lactobacillus rhamnosus GG. The failure to find the GG strain in the vagina indicated it did not reach the site, and the low counts of lactobacilli demonstrated that therapy with this probiotic did not appear to influence the vaginal flora. CONCLUSIONS: BV is not well understood in terms of its causative organisms, and further studies appear warranted using non-culture, molecular methods. Only when the identities of infecting organisms are confirmed can effective therapy be devized. Such therapy may include the use of probiotic lactobacilli, but only using strains which confer a benefit on the vagina of pre- and postmenopausal women.