foods Review Bacterial Biofilms and Their Implications in Pathogenesis and Food Safety Xingjian Bai 1, Cindy H. Nakatsu 2,3 and Arun K. Bhunia 1,3,4,* 1 Molecular Food Microbiology Laboratory, Department of Food Science, Purdue University, West Lafayette, IN 47907, USA;
[email protected] 2 Department of Agronomy, Purdue University, West Lafayette, IN 47907, USA;
[email protected] 3 Purdue Institute of Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN 47907, USA 4 Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA * Correspondence:
[email protected]; Tel.: +1-(765)-494-5443 Abstract: Biofilm formation is an integral part of the microbial life cycle in nature. In food processing environments, bacterial transmissions occur primarily through raw or undercooked foods and by cross-contamination during unsanitary food preparation practices. Foodborne pathogens form biofilms as a survival strategy in various unfavorable environments, which also become a frequent source of recurrent contamination and outbreaks of foodborne illness. Instead of focusing on bacterial biofilm formation and their pathogenicity individually, this review discusses on a molecular level how these two physiological processes are connected in several common foodborne pathogens such as Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica and Escherichia coli. In addition, biofilm formation by Pseudomonas aeruginosa is discussed because it aids the persistence of many foodborne pathogens forming polymicrobial biofilms on food contact surfaces, thus significantly elevating food safety and public health concerns. Furthermore, in-depth analyses of several bacterial Citation: Bai, X.; Nakatsu, C.H.; molecules with dual functions in biofilm formation and pathogenicity are highlighted. Bhunia, A.K.