title: A cost-saving algorithm for rapid diagnosis of Staphylococcus aureus and susceptibility to oxacillin directly from positive blood culture bottles by combined testing with BinaxNOW® S. aureus and Xpert MRSA/SA Assay.
abstract: We studied an algorithm combining 2 rapid methods to detect Staphylococcus aureus and its susceptibility to oxacillin directly from positive blood cultures; our goal was to reduce the cost of the procedure, while maintaining accuracy and a short turnaround time. A total of 581 blood cultures containing gram-positive cocci in clusters were tested by BinaxNOW® Staphylococcus aureus Test. Positive samples were further assessed by the Xpert MRSA/SA BC Assay. Phenotypic methods have identified coagulase-negative staphylococci in 505 samples and S. aureus in 76 samples, of which 51 were oxacillin sensitive and 25 were oxacillin resistant. Sensitivity and specificity of the BinaxNOW® Test were 92% and 99%, respectively, compared to the phenotypic method. The Xpert MRSA/SA BC Assay showed complete concordance with phenotypic identification and antimicrobial susceptibility results. The combined rapid assays produced results within 2 hours and reduced the cost by 75% compared with the Xpert MRSA/SA BC Assay if used alone on all blood bottles.
authors: Infectious Diseases Unit, E. Wolfson Hospital, Holon 58100, Israel.
authors: Orit
authors: O
authors: Yossepowitch
authors: Infectious Diseases Unit, E. Wolfson Hospital, Holon 58100, Israel; Sackler School of Medicine, Tel Aviv University, Tal Aviv, Israel. Electronic address: midan@post.tau.ac.il.
authors: Michael
authors: M
authors: Dan
authors: Microbiology Laboratory, E. Wolfson Hospital, Holon 58100, Israel.
authors: Anuta
authors: A
authors: Kutchinsky
authors: Infectious Diseases Unit, E. Wolfson Hospital, Holon 58100, Israel.
authors: Tamar
authors: T
authors: Gottesman
authors: Sackler School of Medicine, Tel Aviv University, Tal Aviv, Israel.
authors: Orna
authors: O
authors: Schwartz-Harari
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D016470:Bacteremia / Q000175:diagnosis* / Q000382:microbiology; D001769:Blood / Q000382:microbiology*; D017046:Cost Savings; D005260:Female; D006801:Humans; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests / Q000191:economics / Q000379:methods; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D055815:Young Adult
keywords: BinaxNOW S. aureus Assay; Blood cultures; Staphylococcus aureus; X pert MRSA/SA BC Assay