Abstract:

Objective: Multidrug-resistant bacteria generally use cell-to-cell communication that leads to biofilm formation as a resistance development mechanism. Some pathogenic bacteria can form biofilms through a mechanism called Quorum sensing (QS). QS inhibition is one of the effective approaches to prevent biofilm formation. Materials and Methods: 20 Lactic acid bacteria (LAB) previously associated with identification by 16S rRNA sequence analysis were used. Antibiofilm activities of metabolites of strains related to microplate based Antibiofilm method on Staphylococcus aureus ATCC 29213, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853. Chromobacterium violaceum ATCC 12472 was used as an indicator in the anti-QS activities of LAB. The study was also performed by ELISA test on the immunomodulatory effect of LAB human peripheral blood mononuclear cells. Results: All of the metabolites tested showed statistically significant antibiofilm activity on biofilms of pathogenic microorganisms. Although there was a difference between metabolites, Lactobacullus paracasei L2 and L20 strains had a high inhibitory effect on S. aureus (95.1%) and P. aeruginosa by 92.7%, respectively. L. plantarum L8 strain had 95.7% antibiofilm activity on E. coli. It was also determined that LAB has anti-QS activities in different concentrations. The immunomodulatory effect of LAB was found to produce higher IFN‐ γ than the controls, whereas IL-10 concentrations were lower. Conclusion: Bacteria use QS to regulate various sequences of functions, including virulence and biofilm formation. Therefore, using bacteria with strong probiotic properties as QS inhibitory agents seems to be a promising approach to reduce or suppress biofilm formation of pathogenic bacteria.

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