Formation and biocide tolerance of Salmonella biofilms

Nontyphoidal Salmonella (NTS) remains the leading cause of foodborne illness in industrialized countries. However, this threat to public and animal health is not wholly limited to food production and consumption, as nosocomial NTS infections in human and veterinary hospitals are also emerging. Beyond the immediate health threat, this observed rise in nosocomial NTS infections is alarming considering the global emergence, spread, and persistence of multidrug-resistant bacteria. Environmental persistence is consistently cited as a potential risk factor for salmonellosis. NTS has the ability to form biofilms, a collection of adherent cells surrounded by an extracellular polymeric substance (EPS) matrix, which may explain this environmental persistence. Cleaning and disinfection protocols are easy and practical procedures implemented to control infectious disease; however, biofilm formation can result in increased biocide tolerance, allowing pathogens to survive typical sanitation procedures. Further, many biocides have either been tested against planktonic cells only, a limited number of serotypes, or biofilms early in formation (24-48 h), and targeted research on mature biofilms is necessary to mitigate NTS. The goal of this research is to inform and guide the creation of a generic, laboratory-validated cleaning and disinfection protocol that will be applicable across multiple livestock industries, food processing facilities, and health care settings.