Inhibitory activity of Lactobacillus plantarum P17630 against Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae

BACKGROUND: The antimicrobial properties associated with lactic acid bacteria having probiotic activities have been confirmed by numerous studies. The urinary and urogenital tracts are often subjected to bacterial infections caused for about 80% by Escherichia coli, and for 20% by other bacteria including Proteus mirabilis and Klebsiella pneumoniae. The excessive use of antibiotics to eradicate these infections has contributed enormously to the development of antibiotic resistances. Therefore, the use of probiotics represents not only an important alternative but also an ethical and sustainable choice. METHODS: This study evaluated the antibacterial activity of the probiotic LAB Lactobacillus plantarum P17630 against Escherichia coli, Proteus mirabilis and Klebsiella pneumoniae by means of the agar spot method and the agar plug diffusion test. RESULTS: Lactobacillus plantarum P17630 showed strong inhibitory activity against various strains of Escherichia coli with inhibition halos ranging between 3.80 cm and 5.09 cm, strong inhibitory activity against Klebsiella pneumoniae and intermediate against Proteus mirabilis, with average inhibition halos of 3.98 cm and 1.20 cm, respectively. CONCLUSIONS: These results confirmed the antimicrobial activity of Lactobacillus plantarum P17630 against Escherichia coli and its antibacterial activity against other bacteria implicated in urinary tract infections and vaginal infection, suggesting its wider therapeutic use in this field.