A survey of antimicrobial usage on dairy farms and waste milk feeding practices in England and Wales

摘要

In recent years, bacteria have emerged with resistance to extended-spectrum cephalosporin antibiotics. These antibiotics are widely used as first line treatments in human medicine. Resistance is mainly conferred by the production of extended-spectrumbeta-lactamases (ESBLs), such as cefotaximases (CTX-M), which are enzymes able to degrade and inactivate a wide range of cephalosporin antibiotics. Most ESBL-producing bacteria isolated from cattle in England and Wales have been enteric Escherichia colifrom dairy calves. The use of cephalosporins in that age group of cattle is usually limited to the injection of individual animals and this is not common practice. However, calves are often fed waste milk collected from cows treated with antibiotics that may select for, and possibly contain, resistant organisms.