Food processing as a risk factor for antimicrobial resistance spread along the food chain

Farms and food industries rely to a large extent on the use of biocides as disinfectants and other antimicrobial agents and preservatives with antimicrobial properties in order to provide food of high microbiological quality and safe for consumers. However, in the last decades it has become apparent that long-term sub-lethal exposure to these antimicrobial agents can exert a selective pressure leading to the emergence and spread of microbial strains with a reduced susceptibility to the used antimicrobials, which can persistently colonize food-processing environments and recurrently contaminate food. In addition, it may induce resistance to unrelated and clinically relevant antibiotics, in a phenomenon known as cross-resistance. This review aims to provide insights on how antimicrobial resistance emergence and spread can be affected by certain food processing activities and to discuss recent research focused on different pathways through which biocides and other antimicrobials could co-select for bacteria resistant to clinically relevant antibiotics.