The combined oxacillin resistance and coagulase (CORC) test for rapid identification and prediction of oxacillin resistance in Staphylococcus species directly from blood culture.
The combined oxacillin resistance and coagulase (CORC) protocol for rapid identification and determination of oxacillin-susceptibility in Staphylococcus spp from blood culture is described. It incorporates a modified direct tube coagulase test (TCT) and a novel 4-hour multiplication-induction step, which increases the expression of staphylococcal PBP2a if present, facilitating detection by a commercial PBP2a latex agglutination kit. The protocol shows excellent sensitivity and specificity for determination of coagulase-positivity in staphylococci from patient blood cultures (96.8% (95% CI 81.5 to 99.8) and 100% (95% CI 75.9 to 100), respectively, n = 47), and for prediction of oxacillin resistance in S aureus directly from patient blood cultures (100% (95% CI 59.8 to 100) and 100% (95% CI 82.2 to 100), respectively (100% accuracy), n = 31) within 5 hours of blood culture positivity.
Carey
B E
BE
Department of Microbiology, Southern General Hospital, Glasgow, Scotland, UK. bryanc1007@hotmail.com
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D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003030:Coagulase / Q000032:analysis; D006801:Humans; D007841:Latex Fixation Tests / Q000379:methods; D008826:Microbial Sensitivity Tests / Q000379:methods; D010068:Oxacillin / Q000494:pharmacology*; D010403:Penicillin Resistance; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000097:blood / Q000175:diagnosis*; D013210:Staphylococcus / Q000145:classification* / Q000187:drug effects / Q000201:enzymology / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000187:drug effects
D000900:Anti-Bacterial Agents; D003030:Coagulase; D010068:Oxacillin