Evaluation of the BinaxNOW Staphylococcus aureus Test for Rapid Identification of Gram-Positive Cocci from VersaTREK Blood Culture Bottles

Abstract

bThe ability of the rapid BinaxNOW Staphylococcus aureus (BNSA) immunochromatographic test (Alere Scarborough, Inc., ME) to accurately differentiate S. aureus from coagulase-negative staphylococci (CoNS) and other Gram-positive cocci (GPC) directly from VersaTREK blood culture bottles was evaluated. A total of 319 positive patient blood culture bottles with GPC seen in clusters with Gram staining were tested using the BNSA test and a direct tube coagulase test (DTCT). The BNSA test was accurate for the detection and differentiation of S. aureus from CoNS and other GPC within 30 min from the time of blood culture positivity and demonstrated a test sensitivity and specificity of 95.8% and 99.6%, respectively. BNSA test results were faxed to the antimicrobial stewardship pharmacist by noon each day in order to evaluate empirical antimicrobial therapy and facilitate more rapid changes or modifications if necessary. Same-day reporting of BNSA test results in conjunction with an antimicrobial stewardship program was more impactful in improving treatment for inpatients with documented S. aureus bacteremia than in reducing empirical vancomycin use in inpatients with CoNS during the first 24 h following reporting.

Development of a Prototype Lateral Flow Immunoassay for Rapid Detection of Staphylococcal Protein A in Positive Blood Culture Samples

“…However, an in-house LFIA for detection of S. aureus from positive blood culture samples has not yet been reported. Recently, BinaxNOW Staphylococcus aureus test (Alere Scarborough, Inc., Scarborough, ME, USA) for detection of S. aureus from positive blood culture bottles was evaluated [ 48 , 49 , 50 ]. Despite its high sensitivity and specificity, this commercial test is costly (approximately $10.00 per test) [ 48 ].…”

“…Recently, BinaxNOW Staphylococcus aureus test (Alere Scarborough, Inc., Scarborough, ME, USA) for detection of S. aureus from positive blood culture bottles was evaluated [ 48 , 49 , 50 ]. Despite its high sensitivity and specificity, this commercial test is costly (approximately $10.00 per test) [ 48 ]. Although latex and coagulase tests are reliable and easy to perform in routine laboratories, the latex test requires a pure culture (at least one day) and the coagulase test takes several hours for incubation and needs intermittent observation of the plasma clotting [ 19 ].…”

Advances in Rapid Molecular Blood Culture Diagnostics: Healthcare Impact, Laboratory Implications, and Multiplex Technologies

“…While they may not have enjoyed widespread use, they bear mentioning as creative avenues for cost-effective, rapid diagnostics. An immunochromatographic method for detection of S. aureus from blood cultures in less than 30 min (Binax NOW, Alere) had promising performance characteristics and could be used in conjunction with serologic PBP2a detection for MRSA (59,60). A bacteriophage-based method, the KeyPath MRSA/ MSSA blood culture test (MMBT, MicroPhage, Inc) was FDA cleared in 2012 but did not sustain longterm commercial availability.…”

Direct Identification of Staphylococcus aureus and Determination of Methicillin Susceptibility From Positive Blood-Culture Bottles in a Bact/ALERT System Using Binax Now S. aureus and PBP2a Tests

“…Similar false negative BNSA tests were reported by Dhilman et al . [ 9 ] and Yossepowitch et al . [ 10 ], with 2/2 and 4/5 false negative results, respectively, found for mixed SA/CNS BC.…”

“…[ 12 ] (sensitivity [Se]: 97.6%; specificity [Sp]: 100%) and Dhiman et al . [ 9 ] (Se: 95.8%; Sp: 99.6%), probably due to their use of charcoal-free BC bottles, Bactec and VersaTREK, respectively.…”