Comparison of commercial slide agglutination kits with a tube coagulase test for the rapid identification of Staphylococcus aureus from blood culture

摘要

Eighty clinical specimens of BACTEC 9240 blood culture vials, culture positive for staphylococci (38 Staphylococcus au- reus and 42 coagulase negative staphylo- cocci), were tested directly for the presence of clumping factor/protein A and free coagulase. Seven commercial slide agglutination kits were compared with a direct-tube coagulase (DTC) method. All tests were performed on blood culture pellets. Sensitivity, specificity, and nega- tive and positive predictive values for the seven commerical kits were extremely variable, whereas a two-hour DTC test was highly predictive of S aureus.