title: Bovine Staphylococcus aureus: diagnostic properties of specific media.
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.
authors.affiliation: Clinic for Ruminants, Department of Clinical Veterinary Medicine, Vetsuisse-Faculty, University of Berne, Bremgartenstrasse 109a, P.O. Box 8466, 3001 Berne, Switzerland. hans.graber@vetsuisse.unibe.ch
authors.forename: H U
authors.initials: HU
authors.lastname: Graber
authors.forename: S
authors.initials: S
authors.lastname: Pfister
authors.forename: P
authors.initials: P
authors.lastname: Burgener
authors.forename: R
authors.initials: R
authors.lastname: Boss
authors.forename: M
authors.initials: M
authors.lastname: Meylan
authors.forename: J
authors.initials: J
authors.lastname: Hummerjohann
mesh_terms: D000818:Animals; D002417:Cattle; D015169:Colony Count, Microbial / Q000662:veterinary; D003470:Culture Media; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D005260:Female; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000382:microbiology*; D008892:Milk / Q000382:microbiology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology / Q000662:veterinary*; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial