The determination of antimicrobial and antibiofilm activities of foodborne lactic acid bacteria against Enterobacter cloacae isolates

The aim of this study was to investigate the antimicrobial and antibiofilm activities of 10 different lactic acid bacteria (LAB) strains isolated from local food sources of animal origin against 4 Enterobacter cloacae isolates obtained from clinical cases and determine their adhesion potentials to intestinal epithelial cells. In this study, all Enterobacter cloacae isolates (P3, P4, P5, P7) identified with the BD Phoenix automation system were detected to form biofilm with both Congo red agar and Microtiter plate methods. Amoxicillin-clavulanate, cefuroxime, and ampicillin resistance was determined in all isolates. It was determined that LAB strains producing exopolysaccharide (EPS) were able to colonize intestinal epithelial cells. It is noteworthy that LAB extracts were effective to inhibit the biofilm formation of P3Ec, which had higher antibiotic resistance than those of other isolates. Antimicrobial effect of LAB extracts on Enterobacter cloacae were also detected by both agar disc diffusion and well diffusion tests. In this study, all of the isolated LAB strains (especially L. lactis, L. fermentum, and L. casei) are good candidates for controlling Enterobacter cloacae biofilm formation. These findings indicate that L. lactis, L. fermentum, and L. casei can potentially be developed as novel antibiofilm agents.