Wang Hsin-Yao, Tseng Yi-Ju, Lin Wan-Ying, Wang Yu-Chiang, Lin Ting-Wei, Hsu Jen-Fu, Wu Marie Yung-Chen, Wu Chiu-Hsiang, Kalpana Sriram, Lu Jang-Jih
Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan 333, Taiwan.
School of Medicine, National Tsing Hua University, Hsinchu 300044, Taiwan.
Biomedicines. 2024 Sep 20;12(9):2134. doi: 10.3390/biomedicines12092134.
Carbapenemase-producing organisms (CPOs) present a major threat to public health, demanding precise diagnostic techniques for their detection. Discrepancies among the CPO tests have raised concerns, partly due to limitations in detecting bacterial diversity within host specimens. We explored the impact of an unbiased colony selection on carbapenemase testing and assessed its relevance to various tests. Using the FirstAll method for unbiased colony selection to reduce bias, we compared the results from different methods, namely the modified carbapenem inactivation method/EDTA-modified carbapenem inactivation method (mCIM/eCIM), the Carba5, the CPO panel, and the multiplex PCR (MPCR). We compared the FirstAll method to the conventional colony selection for MPCR with seven CPO species. In addition, we evaluated the test performance on seven CPO species using MPCR as a reference and the FirstAll method as the colony-selection method. The results revealed that the selections from the FirstAll method have improved rates of carbapenemase detection, in comparison to approximately 11.2% of the CPO isolates that were noted to be false negatives in the conventional colony-selection methods. Both the Carba5 test and the CPO panel showed suboptimal performance (sensitivity/specificity: Carba5 74.6%/89.5%, CPO panel 77.2%/74.4%) in comparison to the FirstAll method. The Carba5 test provided specific carbapenemase class assignments, but the CPO panel failed in 18.7% of the cases. The Carba5 test and the CPO panel results correlated well with ceftazidime-avibactam minimal inhibitory concentrations (MICs). The concordance for Class A/D with MICs was 94.7% for Carba5 and 92.7% for the CPO panel; whereas for Class B, it was 86.5% for Carba5 and 75.9% for the CPO panel. In conclusion, FirstAll, as the unbiased colony-selection method, was shown to impact carbapenemase testing. With FirstAll, the diagnostic performance of both the Carba5 and the CPO panel was found to be lower. Furthermore, the utilization of ceftazidime-avibactam guided by either the CPO panel or Carba5 was appropriate.
产碳青霉烯酶微生物（CPO）对公众健康构成重大威胁，因此需要精确的诊断技术来检测它们。CPO检测结果之间存在差异，这引发了人们的担忧，部分原因是在检测宿主标本中的细菌多样性方面存在局限性。我们探讨了无偏菌落选择对碳青霉烯酶检测的影响，并评估了其与各种检测方法的相关性。使用FirstAll方法进行无偏菌落选择以减少偏差，我们比较了不同方法的结果，即改良碳青霉烯灭活法/EDTA改良碳青霉烯灭活法（mCIM/eCIM）、Carba5、CPO检测板和多重PCR（MPCR）。我们将FirstAll方法与传统的MPCR菌落选择方法用于七种CPO菌种进行了比较。此外，我们以MPCR为参考，FirstAll方法为菌落选择方法，评估了对七种CPO菌种的检测性能。结果显示，与传统菌落选择方法中约11.2%的CPO分离株被判定为假阴性相比，FirstAll方法的碳青霉烯酶检测率有所提高。与FirstAll方法相比，Carba5检测和CPO检测板的性能都不太理想（敏感性/特异性：Carba5为74.6%/89.5%，CPO检测板为77.2%/74.4%）。Carba5检测能提供特定的碳青霉烯酶类别归属，但CPO检测板在18.7%的病例中失败。Carba5检测和CPO检测板的结果与头孢他啶-阿维巴坦最低抑菌浓度（MIC）相关性良好。Carba5和CPO检测板对A/D类与MIC的一致性分别为94.7%和92.7%；而对于B类，Carba5为86.5%，CPO检测板为75.9%。总之，FirstAll作为无偏菌落选择方法，被证明会影响碳青霉烯酶检测。使用FirstAll时，发现Carba5和CPO检测板的诊断性能较低。此外，由CPO检测板或Carba5指导使用头孢他啶-阿维巴坦是合适的。
