Bovine Lactoferrin can Decrease the In Vitro Biofilm Production and Show Synergy with Antibiotics Against Listeria and Escherichia coli Isolates

Background: Bovine Lactoferrin (bLf) has been reported as antimicrobial, antiviral, immunomodulatory and anticancer protein. Escherichia coli and Listeria spp. are food-borne bacteria that can produce illness in human being and mammals, the emergent antimicrobial drug resistance has been reported in these pathogens. Objective: The aim for this study was to evaluate the bLf effect on in vitro biofilm production and the synergic effect of antibiotics on E. coli and Listeria isolates. Methods: E. coli and Listeria specimens were isolated from bovine carcasses and slaughterhouses surfaces, respectively. Biofilm formation was analyzed with or without bLf, incubated for 48 h and spectrophotometry, cell viability was analyzed by colony-forming unit (CFU) and the synergistic effect of bLf with ampicillin, oxytetracycline, and streptomycin was evaluated through the fractional concentration index (FCI). Results: Our results show that a low bLf concentration (0.8 μM) can diminish the in vitro biofilm production in Listeria isolates; also improves the in vitro oxytetracycline and streptomycin activity against E. coli, and ampicillin activity against Listeria isolates. Conclusion: bLf can affect the biofilm production in Listeria isolates from slaughterhouses surfaces and shown synergic effect with ampicillin. Also has a synergic effect with oxytetracycline and streptomycin against E. coli isolates from bovine carcasses.