Background: For biotechnological application, selected lactic acid bacteria strains belonging to the genera Lactobacillus (Lb) are proposed as an alternative to the antibiotics for the prevention and treatment of urogenital tract infections.
Objectives: Isolating and selecting vaginal lactobacilli strains for probiotic use based on their technological and probiotic aptitudes.
Materials and methods: The vaginal isolates were examined for their essential characteristics as the potential probiotic such as low pH tolerance, bile-salt and simulated human intestinal fluid (SIF) resistance, adhesion to the vaginal epithelial cells (VECs), aggregation and coaggregation, surface hydrophobicity, antimicrobial activity, acid production, antibiotic resistance, and resistance to spermicides. The best strain was identified by PCR.
Results: From 70 lactobacilli isolates and according to the 16 rDNA sequences, isolates B6 and B10 showed the closest homology (99%) to the Lb. gasseri and Lb. plantarum respectively. They produced hydrogen peroxide (H2O2), tolerant to acid, bile, simulated human intestinal fluid, present a strong adhesion, highest percentages of aggregation, and antibacterial activity. These strains are resistant to the spermicide and actively acidify the growth medium.
Conclusions: Strains Lb. plantarum B10 and Lb. gasseri B6 have a strong potential probiotic confirming their value as a tool for prevention against urinary and vaginal infections.
Keywords: Adherence; Aggregation; In vitro; Lactobacilli; PCR; Vaginal tract.