Listeria spp. contamination in a butcher shop environment and Listeria monocytogenes adhesion ability and sensitivity to food-contact surface sanitizers

This study evaluated the occurrence of L. monocytogenes in the processing environment of a butcher shop, and the in vitro adhesion capacity and sensitivity of isolates to two sanitizers: A (Mister MaxDG1, chlorine based) and B (B-Quart Sept, quaternary ammonium based). Of the total of 40 samples, 75% were positive for Listeria spp. and 22.5% for L. monocytogenes. 20 isolates were from serogroup 1/2c or 3c, with positive results for all tested virulence genes. All isolates presented adhesion potential. The evaluated sanitizers had the potential to inhibit isolates growth and adhesion, and removed formed biofilms. After evaluation, the sanitizers were adopted by the butcher shop in its sanitation routine, being effective against L. monocytogenes. Collected data allowed identification of adhesion potential by L. monocytogenes and the effectiveness of the tested sanitizers to control contamination by this pathogen. Practical applicationsThe presented study shows the adhesion potential of L. monocytogenes, as well as the resistance of isolates to chlorine and quaternary ammonium based sanitizers, relevant to food facilities cleaning. Finally, we demonstrated the effects of chlorine and quaternary ammonium sanitizers activity on L. monocytogenes biofilm, leading further procedures to avoid adhesion.