2011 - 2014
Riskfactors for antimicrobial resistance in enteric Escherichia coli from calves in dairy herds
In Sweden the situation with regard to antimicrobial resistance is more favorable than in most other countries. However, in dairy calves resistance to antimicrobials used in humans and animals is most common in generic E. coli of the intestinal flora. Also, multiresistance is common. Resistance is often transferable and bacteria of the intestinal flora thereby constitute a reservoir for resistance genes transferable to bacteria pathogenic to animals and humans. In a study in 300 dairy herds the correlation between resistance and use of antimicrobials is studied. The objective is to identify risk factors for resistance and to define measures to eliminate these factors. Examples of such measures are recommendations on how waste milk from cows treated with antimicrobials can be used for calves without selecting for resistance in bacteria of the intestinal flora. Reducing occurrence of resistance contributes to preserve antimicrobials efficacious for treatment of animals and humans.