Jing Xiaopeng, Hu Yanyan, Wu Tingting, Zhang Xing, Luo Shaofeng, Wang Wei, Min Xiaochun, Sun Ruiling, Zeng Ji
Department of Clinical Laboratory, Wuhan Fourth Hospital, Wuhan, China.
Clinical Microbiology Laboratory, School of Medicine, 2nd Affiliated Hospital of Zhejiang University, Zhejiang University, Hangzhou, China.
Front Microbiol. 2023 Jan 13;13:1096987. doi: 10.3389/fmicb.2022.1096987. eCollection 2022.
Carbapenemase-producing (CPE) are a major health threat worldwide, and therefore the development of rapid detection methods is needed. Here, we established a method to distinguish metallo-β-lactamase and serine carbapenemases using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with ethylenediaminetetraacetic acid (EDTA) and phenylboronic acid (PB).
To assess the specificity and sensitivity of the method, 110 carbapenemase-producing and 72 carbapenemase-negative isolates were collected, among which 51 strains produced only metallo-β-lactamase, 55 strains only serine carbapenemases, and four strains both metallo-β-lactamase and serine carbapenemases. In the proposed MALDI-TOF MS method, imipenem (IPM) and the bacterial strains to be tested were mixed, EDTA and/or PB was added, and the mixture was incubated for 4 h. The carbapenemase type was confirmed by the IPM waveform spectrum before and after incubation.
Based on the presence, absence, and recovery of the IPM-cyano-4-hydroxy-cinnamic acid-specific waveform peak near 479 m/z, the detection sensitivity and specificity of the method were 98.2 and 100%, respectively.
Although CPE detection by MALDI-TOF MS has been studied previously, our method distinguishes between metallo-β-lactamase and serine carbapenemases, which will be very helpful for the clinical selection of antibiotics.
产碳青霉烯酶（CPE）细菌是全球主要的健康威胁，因此需要开发快速检测方法。在此，我们建立了一种使用基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）结合乙二胺四乙酸（EDTA）和苯硼酸（PB）来区分金属β-内酰胺酶和丝氨酸碳青霉烯酶的方法。
为评估该方法的特异性和敏感性，收集了110株产碳青霉烯酶菌株和72株非产碳青霉烯酶菌株，其中51株仅产生金属β-内酰胺酶，55株仅产生丝氨酸碳青霉烯酶，4株同时产生金属β-内酰胺酶和丝氨酸碳青霉烯酶。在所提出的MALDI-TOF MS方法中，将亚胺培南（IPM）与待检测的细菌菌株混合，加入EDTA和/或PB，混合物孵育4小时。通过孵育前后的IPM波形光谱确认碳青霉烯酶类型。
基于479 m/z附近IPM-氰基-4-羟基肉桂酸特异性波形峰的有无及恢复情况，该方法的检测灵敏度和特异性分别为98.2%和100%。
尽管此前已对通过MALDI-TOF MS检测CPE进行了研究，但我们的方法可区分金属β-内酰胺酶和丝氨酸碳青霉烯酶，这将对临床抗生素选择非常有帮助。
