Annette Nygaard Jensen
Senior Researcher
DTU National Food Institute
Research Group for Food Microbiology and Hygiene
Henrik Dams Allé
Building 204 Room 229
2800 Kgs. Lyngby
Danmark
Insects Flies Microbial Food Safety Detection of pathogens Organic Farming Transmission of pathogens
My research focuses on transmission and control of food borne pathogenic bacteria in primary production and means to enhance food safety in food production chains. There has been an increased interest in rearing insects for feed and food, and it is important to assess microbiological safety issues related to this new live-stock production form. In the inVALUABLE project about establishment of mealworm production in DK, experimental studies were investigating the concentration of Salmonella and Bacillus in mealworms following contamination of their feeding substrate. A special focus is to investigate the risk associated with recirculation of organic side-streams currently banned as feeding substrate for insects in EU. This is aimed at providing the knowledge base required to initiate regulatory changes to allow exploitation of low-value organic residues as feeding substrate for insects. If such changes can be made without comprising food safety, it could help to promote circular bioeconomy and recover valuable resources back into the food chain. There is great interest in being able to provide non-chemical, animal-friendly ways to reduce the incidence of pathogens in livestock, especially in organic farming. I have been working with experimental field trials assessing the pathogen reducing effect of various feed interventions. For example, feeding young calves with milk fermented by selected lactic acid bacteria with the capacity to hamper the virulence of pathogens like Salmonella Dublin and enterotoxigenic Escherichia coli (CalfCare). For broilers, assessment of the Campylobacter reducing effect of various feed supplements accepted for use also in organic farming (SafeChicken). Also, the prebiotic effect of chicory and lupin supplemented feedstuff for organic pigs via stimulation of the growth of special fermenting bacteria in their gut, expected to benefit the health of pigs and their ability to withstand pathogen infections (QEMP). Another intervention option for Campylobacter in chickens is to reduce the level of bacteria on the chicken carcasses during slaughter using IceGun technology, i.e. spraying with slurry ice to increase the cooling speed (ChillBact and SafeChicken). Moreover, houseflies have been found to play a role in transmission of Campylobacter to chicken flocks, but knowledge on Campylobacter survival in flies was lacking. A fly infection model has therefore been used for investigating Campylobacter survival in flies, incl. genes important for survival (CamChain). Further research projects investigated whether organic pig production with restricted consumption of antibiotics results in less resistant bacteria in organic pork across four European countries, and if the utilization of livestock manure for fertilizing organic vegetables constitutes a higher risk for fresh produce being contaminated with zoonotic pathogens.