LACTIC ACID BACTERIA AGAINST PATHOGENIC MICROBES

Background: Lactic acid bacteria (LAB) have become an attractive option of modern medical practice. Recently, attention has been paid to their health-promoting properties. Of particular importance are their probiotic properties and specially the ability to compete with pathogens in vivo. Aim: To determine the antagonistic activity of 46 LAB strains against antibiotic-resistant and other outpatient bacterial strains. Methods: Different standard protocols conform to the international rules for the data collection on antimicrobial susceptibility and on metabolic activity were applied. Results: Our hypothesis was that LAB microbiota from complex ecosystems is able to express a broad spectrum of activity. Thus, 12 vaginal lactobacilli and 34 food-originated lactobacilli, lactococci and enterococci were studied. The production of organic acids is clearly involved in antagonistic activity of these bacteria in vitro. Eight out of the tested isolates were active against Staphylococcus aureus MRSA. The inhibitory activity of two vaginal and four food-originated strains was protease-sensitive and independent of the presence of lactic acid and H2O2. Conclusion: These results are encouraging and prompt further research of the active LAB strains and their possible application to overcome the problem with increasing multi-drug resistance in clinical practice.