Biology of foodborne pathogens on produce.

This chapter reviews the attachment to and localization of human pathogens on the surfaces of plants. It first describes the physicochemical environment of plant surfaces to which bacteria must attach to survive and proliferate. It then summarizes the major known mechanisms of attachment of bacteria to plants, with special reference to the similarities between the cell surface moieties of plant-associated bacteria and those of human pathogens. The chapter discusses the research that has been conducted on the localization of human pathogenic bacteria on plant surfaces. It presents experimental evidence for the internalization of human pathogens in plants, as well as for their persistence on and in field-grown crops. More recently, research has begun to document the ability of foodborne pathogens to persist once attached to plant surfaces. The chapter presents some of the most relevant findings regarding the persistence of human pathogens on plants, supporting the hypothesis that preharvest bacterial attachment and subsequent survival may result in the consumption of contaminated produce. It further emphasizes the need to understand in greater detail the mechanisms by which foodborne pathogens attach to plant tissues and the ecology of these bacteria in the plant-soil environment. In contrast, the ability of foodborne pathogens to attach to plant surfaces has only begun to be characterized chemically and molecularly.