Status quo, routes of entry and influence of storage conditions
Adulteration of foods with human pathogenic bacteria is a persistent food safety risk. Foodborne bacterial disease in Germany involves mainly cases of campylobacteriosis, with high infection levels being documented in Germany as well as in other European countries. Most of the cases of campylobacteriosis or salmonellosis have a zoonotic origin. Little information is available on the presence of human pathogenic bacteria in fresh produce. Against this background, the Department of Microbiology and Biotechnology and the Department of Safety and Quality of Fruit and Vegetables work together closely in an inter-departmental project that aims to monitor the prevalence of human pathogens in fresh plant products such as carrots, tomatoes, cucumbers, herbs, green and mixed salads. This is especially important as these products are often consumed in unprocessed and raw form without appropriate inactivation of the microorganisms by a heat processing step. The studies serve to provide data on the incidence of relevant human pathogens in these food products in Germany. For this, samples of the above-mentioned products are investigated at regular intervals for the incidence and contamination levels of pathogens such as Listeria monocytogenes, Salmonella spp., Staphylococcus aureus, Bacillus cereus, as well as pathogenic Escherichia coli, including enterohaemorrhagic E. coli (EHEC) strains. For this, molecular biological methods such as multiplex PCR or quantitative PCR protocols are developed and applied together with classical microbiological cultivation techniques in order to detect, isolate and characterize pathogens from fresh produce. The influence of storage conditions on the growth of human pathogens in vegetal products will be assessed in challenge experiments. The use of bacteriophages as biocontrol tool to combat human pathogens in vegetal products is a specific decontamination strategy that will be investigated in this project. This project is partly funded by the QS-Science Funds. Project duration: 1 year (May 2016 until April 2017).
