Antimicrobial resistance in<i>Staphylococcus aureus</i>,<i>Streptococcus uberis</i>and<i>Streptococcus dysgalactiae</i>from dairy cows with mastitis

Abstract

Resistance to penicillin was found in a quarter of S. aureus isolates, but in virtually no Streptococcus isolates; therefore microbial identification and sensitivity testing would be beneficial when assessing treatment options. The source of the isolates affected the estimated MIC, suggesting that selection of isolates for monitoring of resistance requires care and that use of routine submissions to commercial laboratories to assess antimicrobial resistance patterns may result in biased estimates of prevalence of resistance.