P1-160 Investigation of Virulence Potential and Antimicrobial Resistance of Bacteriocinogenic Lactic Acid Bacteria Obtained from Homemade Cheese

Monday, August 1, 2016
America's Center - St. Louis
Valeria Quintana Cavicchioli, Universidade Federal do Parana, Palotina, Brazil
Anderson Carlos Camargo, Universidade Federal de Viçosa, Viçosa, Brazil
Svetoslav Todorov, Universidade Federal de Viçosa, Viçosa, Brazil
Luís Augusto Nero, Universidade Federal de Viçosa, Viçosa, Brazil
Introduction: Bacteriocinogenic strains are interesting as starter cultures to improve the safety and quality of the food products. However, to be safely applied, the strains must be free of risk to consumers. In this way, investigating the safety of isolates with bacteriocinogenic potential is important to ensure the human health.

Purpose: The aim of this study was to verify the presence of virulence factors, biogenic amines production, antimicrobial resistance and the presence of encoding genes of such virulence factors.

Methods: E. hirae ST65ACC and P. pentosaceus ST57ACC isolated from homemade cheese made with raw milk were subjected to PCR reactions to identify 52 genes related to antimicrobial resistance and virulence activity. Phenotypic methods were also used to identify biogenic amine production (tyramine, histamine, putrescine and cadaverine), virulence factors (gelatinase, hemolysis, lipase, DNAse,) and resistance to 12 antimicrobials (ampicillin, penicillin G, oxacillin, clindamycin, erythromycin, gentamicin, imipenem, rifampicin, chloramphenicol, tetracycline, trimethoprim/sulfamethoxazole, and vancomycin).

Results: The tested isolates presented distinct combinations of antimicrobial resistance genes, but not necessarily the expression of such factors. For P. pentosaceus ST57ACC, eight genes were present, related to resistance to aminoglycosides, erythromycin and vancomycin, while in phenotypic tests, such isolate was resistant to vancomycin, oxacillin and trimethoprim/sulfamethoxazole. For E. hirae ST65ACC, only five genes, related to resistance to tetracycline, vancomycin and streptogramin were positive, and also phenotypic resistant to vancomycin, oxacillin and trimethoprim/sulfamethoxazole. None of the isolates presented production of biogenic amine and the virulence factors phenotypic tested.

Significance: Obtained results indicated the relevance of identifying virulence-related genes in bacteriocinogenic strains, demanding care in their usage as starter cultures or biopreservatives due to the possibility of horizontal gene transfer to other bacteria in food systems. Acknowledgments: CAPES, CNPq and FAPEMIG.