Use of phage applications to combat MRSA at the sow-piglet interface to reduce exposure of staff and contamination of the environment
The main risk factor for human carriage of livestock associated methicillin-resistant Staphylococcus aureus is direct contact with colonized animals or contaminated environmental materials, along with airborne exposure. Sows are at the top of the pig production pyramid, when colonized, constitute a permanent source of MRSA further down the production pyramid. An all-in all-out strategy with efficient cleaning and disinfection is economically not feasible in pig breeding units. This study aims at breaking the cycle through successfully raising MRSA-negative piglets from positive sows to reduce the infection pressure in the production chain and the associated human and environmental exposure. Interventions will be applied to reduce MRSA directly on the mother-offspring interface by using farm-specific phage-cocktails sow-piglet interface. MRSA reduction will be studied through repeated sampling of sows and piglets. Likewise, the impact of the phage treatment on the microbiome dynamics and specifically on MRSA in animals, their environment and in bioaerosols including the exposure of farm staff will be investigated by meta-omics-approaches. The impact of the phage application on the prevalence of MRSA in breeding pigs, herds receiving breeding pigs and the effect on the colonisation of farm staff and public health will be investigated by modelling. Phage application is expected support “one health” by reducing MRSA in the animal population and consequently reducing exposure of farm staff and environmental contamination.
- Bernd-Alois Tenhagen, German Federal Institute for Risk Assessment, Germany (Coordinator)
- Udo Jäckel, Federal Institute for Occupational Safety and Health, Germany (Partner)
- Thomas Rosendal, National Veterinary Insitute (SVA), Sweden (Partner)
- Kyrre Kausrud, The Norwegian Veterinary Institute, Norway (Partner)
- Annemarie Käsbohrer, University of Veterinary Medicine, Austria (Observer)
This project addresses the issue of occupational and environmental exposure to livestock-associated MRSA in pig farms. Using bacterial phages, we will try to reduce the transmission of MRSA from sows to their piglets during the nursing phase. Specific phage cocktails will be designed using several phages to control MRSA on the skin of sows and in their environment. This is done to produce MRSA negative piglets in herds despite having positive sows. A reduction of MRSA in the piglets is expected to contribute to the reduction of MRSA in the whole pig production pyramid. This in turn will reduce the exposure of people working on pig farms and at slaughterhouses to this kind of MRSA. In regions with intensive pig husbandry, livestock associated MRSA may contribute substantially to the overall burden of MRSA in the hospital sector. We aim to reduce this burden. At the same time we will study potential side effects of the use of phages in pigs on the bacterial community living on pigs, in their environment and in aerosols found in pig stables. We will study changes to this community and will also study the persistence of the bacterial phages in the bacterial community and the environment. Finally we will model the effect of the use of the phages on the transmission of the resistant bacteria within the herds, between herds and to the public health system.