Bacterias patógenas lesionadas: metodologías de detección en alimentos

Microorganisms surviving some food processing and preservation conditions are sometimes injured and cannot be detected by conventional techniques or they need time to recover, but they must be considered viable. To study the viability of such injured microorganisms, several techniques have to be combined to detect the nonculturable organisms. Tha main objective of this project is to develop an appropriate method to count and identify sublethally injured microorganisms in foods. For this purpose, it will be studied the survival of Salmonella Enteritidis, Escherichia coli O157:H7 and Listeria monocytogenes inoculated into buffer solution and refrigerated ready-to-eat meals. It will be also identified which manufacture preservation processes (acid conditions, heat and hydrostatic pressure treatment) and storage conditions (cold, vaccuum and modified atmospheres) lead to development of populations of nonculturable injured microorganisms.