Biofilmes de Salmonella Minnesota: formação, influência da superfície, inibição por agentes químicos e importância do período entre tratamentos

Abstract

The main cause of human infection with Salmonella spp. is the ingestion of contaminated food of animal origin, with emphasis on poultry meat and its derivatives. Among the most isolated paratyphoid Salmonella in Brazil, the serovar Minnesota has been noted for its high prevalence in chicken samples. However, little is known about the real importance of this serovar in public health, and to date, there are few reports of this serotype as responsible for outbreaks of human salmonellosis worldwide. Biofilm represents an important source of food contamination that may be present at various points in the chicken meat processing chain, and thus may be one of the causes of S. Minnesota's perpetuation in slaughter plants. The dissertation was divided in three chapters, the first referring to the general considerations of the topics covered in the other chapters. The second chapter investigated 29 strains of S. Minnesota isolated in the production chain of two poultry industries with complete production cycle during the period from 2009 to 2014. In the strains were determined the ability to form biofilms, the presence of specific genes related to these communities and the dissemination of strains through genetic similarity. In the third chapter, three of the 29 S. Minnesota strains were selected considering their phylogenetically distinction in molecular typing and in the traditional biofilm classification. In these, the formation of biofilms in materials commonly used in industry, such as polypropylene, polyurethane and stainless steel, were evaluated before and after treatment with sanitizing agents: 1% sodium hypochlorite and 0.8% peracetic acid, and to determine if after these treatments in a favorable environment, there is recovery of the viable microorganism.