Identification of coagulase-negative staphylococci by electrophoretic profile of total proteins and analysis of penicillin-binding proteins.

Analyses of total solubilized proteins and penicillin-binding proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were demonstrated to be accurate methods for the identification of coagulase-negative staphylococci. However, penicillin-binding protein profiles were found to be much clearer for the identification of these organisms to species level than was examination of the total solubilized proteins. By using the former technique, 13 reference strains were found to have species-specific penicillin-binding protein profiles, and 150 of 160 randomly collected clinical isolates were identified as belonging to eight of these species. A group of three clinical strains probably represents the recently described species Staphylococcus lugdunensis; the other seven clinical isolates belonging to five species remained unclassified.