Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
J Antimicrob Chemother. 2018 May 1;73(5):1267-1271. doi: 10.1093/jac/dky015.
To evaluate the performance of a rapid antimicrobial susceptibility testing (AST) platform based on microfluidic chip technology, the QMAC-dRAST, which enables AST from colony isolates or positive blood culture broth (PBCB), and to compare the performance of the QMAC-dRAST for staphylococci and enterococci with that of the VITEK-2 system based on reference broth microdilution (BMD).
A total of 110 staphylococcal and enterococcal isolates from blood cultures were included. AST was performed directly using the QMAC-dRAST with PBCB. Thereafter, colony isolates derived from subculture of PBCB were used for the QMAC-dRAST, the VITEK-2 system and BMD.
The overall agreement between the QMAC-dRAST with PBCB and BMD was 91.5%. There were 1.2% very major errors (VMEs), 4.3% major errors (MEs) and 5.4% minor errors (mEs). The QMAC-dRAST with colony isolates yielded 94.6% agreement and error rates of 1.0% VMEs, 1.8% MEs and 4.0% mEs. The VITEK-2 system showed 96.2% agreement and error rates of 2.3% VMEs, 0.5% MEs and 2.6% mEs. The incubation time in the QMAC-dRAST was significantly shorter than in the VITEK-2 system (median of 6 versus 10 h; P < 0.0001).
The QMAC-dRAST system provided rapid results and represents an alternative to conventional AST methods. The QMAC-dRAST with colony isolates produced more reliable results for staphylococci and enterococci than the QMAC-dRAST with PBCB. The QMAC-dRAST system also performed comparably to BMD and the VITEK-2 system.
评估一种基于微流控芯片技术的快速抗菌药敏测试（AST）平台 QMAC-dRAST 的性能，该平台可从菌落分离物或阳性血培养肉汤（PBCB）中进行 AST，并比较 QMAC-dRAST 对葡萄球菌和肠球菌的性能与基于参考肉汤微量稀释（BMD）的 VITEK-2 系统的性能。
共纳入 110 株来自血培养的葡萄球菌和肠球菌分离株。使用 QMAC-dRAST 直接对 PBCB 进行 AST。此后，使用 QMAC-dRAST、VITEK-2 系统和 BMD 对 PBCB 衍生的菌落分离物进行 AST。
QMAC-dRAST 与 PBCB 和 BMD 的总体一致性为 91.5%。有 1.2%的非常大误差（VME）、4.3%的主要误差（ME）和 5.4%的次要误差（mE）。QMAC-dRAST 与菌落分离物的一致性为 94.6%，VME、ME 和 mE 的错误率分别为 1.0%、1.8%和 4.0%。VITEK-2 系统显示 96.2%的一致性，VME、ME 和 mE 的错误率分别为 2.3%、0.5%和 2.6%。QMAC-dRAST 的孵育时间明显短于 VITEK-2 系统（中位数分别为 6 小时和 10 小时；P<0.0001）。
QMAC-dRAST 系统提供了快速的结果，是常规 AST 方法的一种替代方法。QMAC-dRAST 与菌落分离物对葡萄球菌和肠球菌产生的结果比 QMAC-dRAST 与 PBCB 更可靠。QMAC-dRAST 系统的性能也与 BMD 和 VITEK-2 系统相当。
