LAUSR

Abstract Biofilms characterize sessile form that allows bacterial maintenance under hostile conditions. Salmonella represents an important foodborne zoonotic agent, capable of forming biofilms on diverse surfaces. The emergence of Salmonella Minnesota in the Brazilian poultry production expresses the need for more specific knowledge related to its maintenance in the environment and consequent food contamination, as well as control measures. Our approach combines the analysis of genetic determinants linked to biofilm formation and the phenotypic study of biomass on different surfaces, together with the determination of the effect of chemical agents on the control of sessile structure. It also evaluates the genetic similarity profile of 29 S. Minnesota strains isolated from food and environmental samples in two full-cycle poultry industries from 2009 to 2014. Genetic analysis showed low heterogeneity with the identification of six clonal groups, three clusters with homology greater than 80% and seven distinct genotypes. It was compatible with the presence of important genes in biofilm formation, with 28/29 (97.0%) presenting adrA and csgD and 27 (93.0%) presenting the luxS gene. Allied to this, 19/29 of the strains (66.0%) presented biomass that varied the intensity in weak (9/19–47.0%), moderate (6/19–32.0%) and strong (4/19–21.0%), with characteristic ultrastructure of a mature biofilm. Sodium hypochlorite showed greater efficiency in the control of sessile cells, even after incubation process. The study shows the presence of biofilm-producing S. Minnesota characterizing the problem of persistence in broiler slaughterhouses and indicates as a control strategy the use of sodium hypochlorite in an appropriate manner.