title: The combined oxacillin resistance and coagulase (CORC) test for rapid identification and prediction of oxacillin resistance in Staphylococcus species directly from blood culture.
abstract: 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.
authors.affiliation: Department of Microbiology, Southern General Hospital, Glasgow, Scotland, UK. bryanc1007@hotmail.com
authors.forename: B E
authors.initials: BE
authors.lastname: Carey
authors.forename: L
authors.initials: L
authors.lastname: Nicol
mesh_terms: 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
chemical_list: D000900:Anti-Bacterial Agents; D003030:Coagulase; D010068:Oxacillin