Escherichia coli producing CMY-2 β-lactamase in bovine mastitis milk

J Food Prot. 2012 Jan;75(1):137-8. doi: 10.4315/0362-028X.JFP-11-320.


An Escherichia coli isolate producing the CMY-2 β-lactamase was found in the milk of a cow with recurrent subclinical mastitis. The isolate was resistant to the antibiotics commonly used for intramammary mastitis treatment, such as penicillins, cephalosporins, β-lactam/β-lactamase inhibitor combinations, aminoglycosides, tetracyclines, and sulfonamides. This is the first report of a plasmid-mediated AmpC-producing Enterobacteriaceae in bovine milk.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins
  • Cattle
  • Escherichia coli / drug effects*
  • Escherichia coli / enzymology*
  • Female
  • Humans
  • Mastitis, Bovine / microbiology
  • Microbial Sensitivity Tests
  • Milk / enzymology
  • Milk / microbiology*
  • Prevalence
  • beta-Lactam Resistance
  • beta-Lactamases / biosynthesis*


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • beta-lactamase CMY-2
  • AmpC beta-lactamases
  • beta-Lactamases