Microbiology and Immunology Department, Faculty of Medicine, Cairo University, 1 El-Saraya St., Kasr Al Ainy, Cairo, Egypt.
Clinical Pathology Department, Faculty of Medicine, Cairo University, Cairo, Egypt.
J Glob Antimicrob Resist. 2017 Jun;9:10-14. doi: 10.1016/j.jgar.2016.12.015. Epub 2017 Mar 9.
With a worrisome surge of carbapenem-resistant bacterial isolates, the diagnostic arsenal has become in dire need of affordable and timely assays to detect the rapidly transmissible carbapenemases. Employing multiplex PCR as a reference method, the purpose of the present study was to compare the performance of the carbapenem inactivation method (CIM) and the Carba NP test in the detection of carbapenemase-producers.
A panel of 203 Gram-negative bacterial isolates screened for carbapenem resistance were subjected to the CIM and Carba NP test. The results were compared with multiplex PCR targeting various carbapenemase genes.
According to multiplex PCR, 92 (45.3%) of 203 isolates were found to harbour one or more carbapenemase genes, with bla and bla being the most commonly encountered. The sensitivity and specificity of the CIM were 95.7% and 95.5% respectively, whilst those of the Carba NP test were 75.0% and 99.1%, respectively. Both methods were found to be rapid and reliable in the detection of carbapenemases and showed a high agreement with multiplex PCR.
As the list of carbapenemase genes continues to expand, the reliability of PCR has become doubtful; hence, the CIM and Carba NP test could offer promising alternatives, with the CIM being of a lower cost and less labour intensive.
随着碳青霉烯类耐药细菌分离株数量的令人担忧的激增，诊断工具包迫切需要经济实惠且及时的检测方法来检测具有快速传播性的碳青霉烯酶。本研究采用多重 PCR 作为参考方法，旨在比较碳青霉烯失活法（CIM）和 Carba NP 试验在检测碳青霉烯酶产生菌方面的性能。
对 203 株筛选出的耐碳青霉烯类革兰氏阴性细菌分离株进行 CIM 和 Carba NP 试验。将结果与针对各种碳青霉烯酶基因的多重 PCR 进行比较。
根据多重 PCR，203 株分离株中 92 株（45.3%）携带一种或多种碳青霉烯酶基因，其中 bla 和 bla 最为常见。CIM 的灵敏度和特异性分别为 95.7%和 95.5%，而 Carba NP 试验的灵敏度和特异性分别为 75.0%和 99.1%。两种方法均被发现可快速可靠地检测碳青霉烯酶，与多重 PCR 具有高度一致性。
随着碳青霉烯酶基因的不断增加，PCR 的可靠性变得值得怀疑；因此，CIM 和 Carba NP 试验可能是有前途的替代方法，其中 CIM 成本更低，劳动强度更小。
