Ability of Lactic Acid Bacteria to affect Escherichia coli O157:H7 biofilm formation.

CISNEROS, L.; SAAVEDRA, L.; YANTORNO, O.; FADDA S.

Paraná

Congreso; LIV Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular (SAIB).; 2018

SAIB

Ability of lactic acid bacteria to affect Escherichia coli O157:H7 biofilm formationCisneros, L, Saavedra, L, Yantorno, O, Fadda, SCentro de Referencia para Lactobacilos (CERELA-CONICET). Chacabuco 145. CP 4000. Tucumán, ArgentinaEnterohemorrhagic Escherichia coli (EHEC) is a human pathogen responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome worldwide. Cattle is the main reservoir, therefore fresh meat is considered vehicle of this pathogen. Besides of its different virulence factors, EHEC has the ability to form biofilm on food contact surfaces. On the other hand, some lactic acid bacteria (LAB) can inhibit the growth of certain pathogens so its use as bioprotective agents is usually applied. The objective of this study was to evaluate the ability of five LAB strains to affect EHEC biofilm formation by means of exclusion assay. Also, to complete the molecular characterization of the studied pathogenic strain, the detection of biofilm related genes in E. coli NCTC12900 was assessed and corroborated by PCR. Five LAB strains were selected for their better ability to form biofilm at 10 °C on polystyrene microplates. Pathogenic cells were seeded on a 48h-biofilm of each LAB and incubated for 24 h at 10 °C. Total biofilm cells were collected and enumerated on selective agar media. Lactobacillus plantarum CRL 1075, was able to reduce the pathogen biofilm in one logarithmic unit without affecting its own biofilm viability. P. pentosaceus CRL 908 and CRL 2145 did not affect E. coli sessile cells but their own biofilm was affected differently. L. plantarum CRL 683 and CRL 1482 produced a decrease in the pathogen counts but their own biofilm was negatively affected. This study is a first approximation oriented to found biological solutions to mitigate E. coli biofilm on food surfaces by using bioprotective LAB cultures.