title: Evaluation of methods for differentiation of coagulase-positive staphylococci.
abstract: The purpose of this study was to determine the minimum number of tests that could be used to differentiate between the coagulase-positive strains of staphylococcus: Staphylococcus aureus, Staphylococcus hyicus, and Staphylococcus intermedius. Eighty coagulase-positive strains of each of the three species were examined. The five tests conducted were growth on modified Baird-Parker agar, growth on P agar supplemented with acriflavin, production of acetoin, anaerobic fermentation of mannitol, and presence of beta-galactosidase. Positive test percentages for S. aureus were 100% for growth on modified Baird-Parker agar, 100% for growth on P agar supplemented with acriflavin, 94% for production of acetoin, 99% for anaerobic fermentation of mannitol, and 0% for presence of beta-galactosidase. Positive test percentages for S. intermedius were 0% for growth on modified Baird-Parker agar, 0% for growth on P agar supplemented with acriflavin, 1% for production of acetoin, 0% for anaerobic fermentation of mannitol, and 100% for presence of beta-galactosidase. S. hyicus isolates were negative in all five tests. Results from the 240 coagulase-positive staphylococcus strains tested would suggest correct identification of coagulase-positive staphylococci with P agar supplemented with acriflavin and the beta-galactosidase test. These two tests are simple to conduct and result in quick and easy differentiation of the three coagulase-positive staphylococcal species.
authors.affiliation: Department of Veterinary Clinical Medicine and Surgery, Washington State University, Pullman 99164-6610.
authors.forename: J R
authors.initials: JR
authors.lastname: Roberson
authors.forename: L K
authors.initials: LK
authors.lastname: Fox
authors.forename: D D
authors.initials: DD
authors.lastname: Hancock
authors.forename: T E
authors.initials: TE
authors.lastname: Besser
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D002417:Cattle; D003030:Coagulase / Q000378:metabolism*; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008414:Mastitis, Bovine / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology*; D013210:Staphylococcus / Q000145:classification* / Q000201:enzymology* / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000201:enzymology / Q000302:isolation & purification
chemical_list: D003030:Coagulase