A medium which incorporates CAMP factor produced by Streptococcus agalactiae (group B) into sheep blood agar was used to culture and identify coagulase-positive staphylococci from bovine milk. Of 506 staphylococcal isolates from bovine milk, 92.5% of coagulase-positive organisms produced a wide zone of complete hemolysis, whereas 98.9% of coagulase-negative organisms did not. The agreement of this one-step culture and identification test with the standard tube coagulase test was higher than that of the deoxyribonuclease test medium, Baird-Parker egg yolk medium, tellurite glycine medium and slide coagulase tests.
1Present address: 7919 6th Street NE, Spring Lake Park, MN 55432.
2Department of Large Animal Clinical Sciences, University of Minnesota.
3Department of Biology, Mankato State University, Mankato, MN 56001.
4Quality Control Laboratory, Pabst Meat Supply, Inc., Inver Grove Heights, MN 55075.
5Department of Veterinary Pathobiology, University of Minnesota.