Comparison of Test Methods for Detecting Metallo-β-Lactamase-Producing Gram-Negative Bacteria
Comparison of Test Methods for Detecting Metallo-β-Lactamase-Producing Gram-Negative Bacteria
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DOI：
10.7883/yoken.66.512
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发表时间：
2013-11-01
影响因子：
2.2
通讯作者：
Arakawa, Yoshichika
中科院分区：
文献类型：
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作者：
Hattori, Tatsuya;Kawamura, Kumiko;Arakawa, Yoshichika
近年来，产生多种β-内酰胺酶的革兰氏阴性细菌增多，使得准确识别金属β-内酰胺酶(MBL)的生产者变得困难。在本研究中，使用56株产生各种β-内酰胺酶的革兰氏阴性细菌对六种检测MBL产生菌的方法进行了比较。以巯基乙酸钠(SMA)和乙二胺四乙酸二钠(EDTA)作为双纸片协同试验(DDST)的抑制剂，比较头孢他啶(CAZ)、亚胺培南、美罗培南(MEPM)等抗菌药物与纸片间距的关系。对Etest(R)、DPD1(R)、Cica-Beta(R)和改良Hodge试验进行了比较。在比较的6种方法中，SMA盘法DDST的敏感性(Se)和特异性(Sp)最高。在DDST中，当圆盘之间的距离保持在大约5 mm时，观察到最明显的生长抑制现象。CAZ和SMA仅成功检测到产MBL的菌株(Se，87.5%；Sp，100%)，而MEPM与SMA联合检测其他类型的MBL产生菌，如CTX-M和CMY型酶(Se，79.1%；Sp，100%)，表现出最好的性能。使用SMA和CAZ和/或MEPM的DDST是在常规临床实验室检测中筛选MBL产生菌的一种简单、特异和成本效益高的方法。
The recent increase in gram-negative bacteria coproducing multiple classes of beta-lactamases has made it difficult to accurately identify metallo-beta-lactamase (MBL) producers. In the present study, six methods for detecting MBL producers were compared using 56 gram-negative bacterial isolates that produce various beta-lactamases. Sodium mercaptoacetic acid (SMA) and EDTA were used as inhibitors for a double-disk synergy test (DDST), and antimicrobial agents, including ceftazidime (CAZ), imipenem, and meropenem (MEPM), along with the distance between the disks, were compared. The Etest (R), dry-plate DPD1 (R), Cica-Beta (R), and modified Hodge test were also compared. Among the six methods compared, DDST using the SMA disk showed the highest sensitivity (Se) and specificity (Sp). In DDST, the clearest appearance of growth inhibition was observed when the distance between the disks was maintained at approximately 5 mm. A combination of CAZ and SMA successfully detected only MBL-producing isolates (Se, 87.5%; Sp, 100%), and MEPM exhibited the best performance in combination with SMA in the detection of MBL producers coproducing other classes of beta-lactamases such as CTX-M- and CMY-type enzymes (Se, 79.1%; Sp, 100%). DDST using SMA and CAZ and/or MEPM is a simple, specific, and cost-effective method to screen MBL producers in routine clinical laboratory testing.