Emerging antimicrobial resistance in the food chain: Epidemiology and preventive measures against ESBL producing E. coli

Antimicrobial resistance is recognized as one of the most important global health challenges. WHO has defined cephalosporins, quinolones and macrolides as critically important antimicrobial agents. Resistance to antimicrobial agents is increasing among ba cteria from livestock. Especially, ESBL (extended spectrum betalactamase) producing bacteria, expressing resistance to cephalosporins, have emerged among livestock. Poultry seems to be associated with the highest frequencies of ESBL. Food contaminated wit h resistant bacteria may play an important role in human acquisition of resistant bacteria. It should therefore be an overall goal to keep the level of resistant bacteria in production animals and through the meat processing chain at the lowest possible l evel. In addition, resistant bacteria represent therapeutic challenges for treatment of bacterial infections in poultry. The resistance situation among bacteria from Norwegian livestock is good, representing positive marked advantages for Norwegian agricu ltural products. However, recent surveys have documented a considerable prevalence of ESBL positive E.coli in broilers. The poultry production in Norway is depending on import of breeding animals, this may have contributed to the introduction of resistant bacteria. The project will investigate critical points and risk factors for introduction and dissemination of ESBL positive E.coli in Norwegian poultry production. Furthermore it will be investigated if successful clones or resistance plasmids are dissem inated, and if certain bacterial fitness properties are associated with them. The role of disinfectants along and other environmental processing factors on resistance development and persistence will be studied. This knowledge is necessary to give recomme ndations regarding the risk of acquisition of resistant bacteria through the food chain which will contribute to a stabilization of the favorable resistance situation in Norwegian livestock animals and food supply.