The Growth Inhibition Effect on the Causative Bacteria of Bacterial Vaginosis by Bacterial Strains Isolated from the Vagina of a Healthy Woman

ABSTRACT

Two Gram-positive rod strains isolated from the healthy vagina of a woman were tested for the possibility as probiotics. One strain was identified as Steroidobacter denitrificans (YH1) and the other as Lactobacillus crispatus (YH2) by 16S rRNA partial sequencing. The Casman agar and Man-Rogosa-Sharpe (MRS) agar were mixed in same quantity, supplemented with 5% human rbc lysate (CMB agar). The Wilkins-Chalgren agar and MRS agar were mixed in same quantity (WCM agar). Gardnerella vaginalis was cultured in Casman broth, supplemented with 5% human rbc lysate and 1,000 x-diluted with normal saline. Bacteroides fragilis, Mobiluncus mulieris and Peptostreptococcus asaccharolyticus were cultured in Wilkins-Chalgren anaerobe broth and 2,000x-diluted. S. denitrificans YH1 and L. crispatus YH2 were cultured in MRS broth anaerobically and 100x-diluted. The diluted suspensions of B. fragilis, M. mulieris and P. asaccharolyticus were inoculated on WCM agar and G. vaginalis on CMB agar by cotton swabs. Ten microl aliquots of YH1 and YH2 were inoculated on the center of WCM agar and CMB agar. The growth inhibition zone diameters of B. fragilis, G. vaginalis, M. mulieris and P. asaccharolyticus by YH1 were 35 mm, 35 mm, 25 mm and 60 mm. The inhibition diameters by YH2 were 25 mm, 30 mm, 20 mm and 40 mm, respectively. These results implicate that S. denitrificans YH1 can be the stronger probiotics for the treatment of bacterial vaginosis than L. crispatus, compared inhibition zone diameters by YH1 and YH2.