Profile

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.

Research areas

My research is focused on transmission of food borne pathogenic bacteria (salmonella, campylobacter and E. coli) in the primary production, particularly in organic farming systems.

There has been an increased interest in rearing of insects for feed and food and it is important to assess the food safety of this new live-stock production form. Not least if organic side-streams are to be exploited as feed substrate for the insects in order to increase the circular bioeconomy . Food safety is therefore in focus in relation to the participation in the inVALUABLE project about establishment of mealworm production in DK.

It is shown that houseflies play a role in transmission of campylobacter to chicken flocks, but knowledge on campylobacter survival in flies is lacking. A fly infection model is being used for investigating campylobacter survival in flies, incl. genes important for survival, as part of the EMIDA project CamChain.

Consumption of antibiotics in organic pig production is limited compared to conventional production but the question is whether this is also reflected in less resistant bacteria in organic pork. Especially considering that organic swine are often slaughtered on the same slaughter line as the conventional constituting a potential risk for contamination with resistant bacteria. The CORE Organic II Project SafeOrganic is investigation this across four European countries.

Relatively little is known about the bacterial infection risk associated with vegetables in Denmark, but in recent years outbreaks of disease with bacterial pathogens have been associated with consumption of fresh produce. I have participated in a joint European project with the aim to investigatethe potential infection risk associated with utilization of manure of livestock origin for fertilizing especially organic vegetables, where the use of chemical fertilizers is not allowed. This study involved detection of pathogens in field surveys as well as identification of special risk factors.

There is great interest in being able to provide non-chemical, animal-friendly ways to reduce the incidence of pathogens in pigs instead of conventional treatment, especially in organic farming. I have been working with experimental field trials assessing the bacterial infection risk associated with outdoor pig production systems and the potential beneficial effect of using alternative feedstuffs such as chicory and lupin. These fructan- and fiber-rich feedstuffs will usually stimulate the growth of special fermenting bacteria in the gut and the altered microbial gut microbiota is believed to help the animal to fight invading pathogens.

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