Response of Foodborne Bacteria to Acid Shock (pp. 35-70)
Authors: (Maria Leonor Faleiro, Universidade do Algarve, Portugal)
Abstract: The acid shock response of foodborne pathogens such as the Gram-negative E. coli O157:H7 and the Gram-positive Listeria monocytogenes deduced from in vitro studies is extraordinary and attempts to dissect the true impact of this ability have been made along the past years and the results of the studies showed the existence of several acid resistance systems (ARS). Among the known ARS, the glutamate-dependent system seems to be the most important and correspondently the most investigated. All together the identified ARS, until the present jointly act to protect cells from different acid shock conditions either inside or outside their hosts. Emerging foodborne pathogens, such as Cronobacter sakazakii require a more deep investigation on the identification of the ARS systems that support its survival in low pH foods. Foodborne pathogens are able to adhere even under low pH conditions and the entry into a viable but nonculturable (VBNC) state when the cells are exposed to an acidic environment may constitute a serious risk to food safety.