Cho Hanwool, Kim Jung Ok, Choi Ji Eun, Lee Howon, Heo Woong, Cha Young Jong, Yoo In Young, Park Yeon-Joon
Department of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Department of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
J Microbiol Methods. 2020 Oct;177:106042. doi: 10.1016/j.mimet.2020.106042. Epub 2020 Sep 3.
Rapid detection of carbapenemases and accurate reporting of carbapenem MICs is critical for appropriate treatment and infection control. We evaluated the BD Phoenix NMIC-500 panel for detection and classification of carbapenemases and antimicrobial susceptibility testing (AST) for carbapenems. A total of 235 isolates were tested; 47 carbapenemase-producing Enterobacterales, 52 non-carbapenemase-producing carbapenem-resistant Enterobacterales (non-CP-CRE), 136 carbapenem-susceptible Enterobacterales (CSE). The sensitivity of carbapenemase-producing organism (CPO) detection was 97.9%, the specificity was 100% for CSE but 32.7% for non-CP-CREs. All the 35 false-positive cases were non-CP-CREs; 23 out of the 35 were determined as untyped carbapenemase producer (CP), nine were mistyped as class B, and three were as class A. The detection rate/correct classification rate for class A, B, and D carbapenemase was 100%/78.6%, 100%/100%, and 80%/60%, respectively. To supplement the low specificity, it is suggested to report carbapenemase-producer (CP) positive results as "strongly suspicious for carbapenem resistance but carbapenemase production needs to be confirmed" and perform the confirmatory test. The EA and CA for ertapenem, imipenem, and meropenem was 99.1%/99.6%, 89.4%/90.6%, and 95.3%/95.7%. In conclusion, the BD Phoenix CPO detect panel provides advantage in that the carbapenemase test is automated and the results can be obtained within 6 h but the low specificity in CREs needs to be improved. In addition, accurate reporting of meropenem MICs will be helpful for clinicians to choose treatment options.
快速检测碳青霉烯酶并准确报告碳青霉烯类药物的最低抑菌浓度（MIC）对于恰当的治疗和感染控制至关重要。我们评估了BD Phoenix NMIC - 500检测板用于碳青霉烯酶的检测和分类以及碳青霉烯类药物的药敏试验（AST）。共检测了235株分离菌；47株产碳青霉烯酶肠杆菌科细菌、52株非产碳青霉烯酶的耐碳青霉烯肠杆菌科细菌（非CP - CRE）、136株对碳青霉烯类敏感的肠杆菌科细菌（CSE）。产碳青霉烯酶菌株（CPO）检测的敏感性为97.9%，对CSE的特异性为100%，但对非CP - CREs的特异性为32.7%。所有35例假阳性病例均为非CP - CREs；35例中有23例被判定为未分型的碳青霉烯酶生产者（CP），9例被误分类为B类，3例被误分类为A类。A类、B类和D类碳青霉烯酶的检出率/正确分类率分别为100%/78.6%、100%/100%和80%/60%。为弥补低特异性，建议将产碳青霉烯酶生产者（CP）阳性结果报告为“强烈怀疑耐碳青霉烯，但碳青霉烯酶产生情况需确认”并进行确证试验。厄他培南、亚胺培南和美罗培南对CSE的药敏试验结果解释符合率（EA）和分类符合率（CA）分别为99.1%/99. 6%、89.4%/90.6%和95.3%/95.7%。总之，BD Phoenix CPO检测板的优势在于碳青霉烯酶检测是自动化的，且6小时内可获得结果，但对CREs的低特异性有待提高。此外，准确报告美罗培南的MIC对临床医生选择治疗方案将有所帮助。
