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 “carbapenem-resistant, CP-suspicious” 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和准确报告碳青霉烯MICs对于适当的治疗和感染控制至关重要。我们评估了BD Phoenix NMIC-500面板对碳青霉烯酶的检测和分类以及对碳青霉烯类药物的药敏试验（AST）。总共测试了235个分离株。47个产生碳青霉烯酶的肠杆菌，52个非产生卡巴培南姆的耐碳青霉烯的肠杆菌（非CP-CRE），136个对碳青霉烯敏感的肠杆菌（CSE）。产碳青霉烯酶的生物（CPO）检测的灵敏度为97.9％，对CSE的特异性为100％，对非CP-CRE的特异性为32.7％。35例假阳性病例均为非CP-CRE。在35个样本中，有23个被确定为未分型的碳青霉烯酶生产商（CP），有9个被误分为B类，三个被分类为A类。A，B和D类碳青霉菌酶的检出率/正确分类率为100％/ 78.6 ％，100％/ 100％和80％/ 60％。为了补充低特异性，建议报告碳青霉烯酶生产者（CP）阳性结果为“耐卡巴培南，可疑CP”并进行确认试验。厄他培南，亚胺培南和美洛培南的EA和CA为99.1％/ 99.6％，89.4％/ 90.6％和95.3％/ 95.7％。

总之，BD Phoenix CPO检测板具有的优势在于，碳青霉烯酶测试是自动化的，可以在6小时内获得结果，但CRE的低特异性需要改善。此外，准确报告美罗培南MIC有助于临床医生选择治疗方案。