Bovine Staphylococcus aureus: diagnostic properties of specific media

Res Vet Sci. 2013 Aug;95(1):38-44. doi: 10.1016/j.rvsc.2013.02.023. Epub 2013 Mar 30.

Abstract

As accurate discrimination between Staphylococcus (S.) aureus and NSA (non-S. aureus staphylococci) involved in bovine mastitis is essential in terms of clinical prognosis and outcome, the aim of this study was to reevaluate the classical bacteriological procedures to identify these agents. Various media and the coagulase tube test were investigated using 116 strains of S. aureus and 115 of NSA, all isolated from cows with spontaneous intramammary infections (IMI). Furthermore, 25 NSA reference strains were analyzed. The study demonstrated that a few media were appropriate for differentiating S. aureus from NSA, provided that the staphylococci were isolated from bovine IMI. Evaluation of hemolysis further revealed that double or incomplete hemolysis are specific for S. aureus and are, therefore, a decisive diagnostic criterion. For strains showing complete hemolysis, maximal discrimination between S. aureus and NSA was observed by subculturing them on CHROMagar Staph. aureus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Colony Count, Microbial / veterinary
  • Culture Media
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Female
  • Mastitis, Bovine / diagnosis
  • Mastitis, Bovine / microbiology*
  • Milk / microbiology
  • Polymerase Chain Reaction / veterinary
  • Sensitivity and Specificity
  • Staphylococcal Infections / diagnosis
  • Staphylococcal Infections / microbiology
  • Staphylococcal Infections / veterinary*
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / isolation & purification*

Substances

  • Culture Media
  • DNA, Bacterial