Department of Microbiology, School of Medicine, Kyungpook National University, Daegu, Korea.
Kyungpook National University Hospital National Culture Collection for Pathogens (KNUH-NCCP), Kyungpook National University Hospital, Daegu, Korea.
Ann Lab Med. 2024 Sep 1;44(5):410-417. doi: 10.3343/alm.2023.0369. Epub 2024 Mar 4.
Carbapenem resistance in is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible isolates from three Korean hospitals.
A total of 155 carbapenem-non-susceptible isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase.
Sixty STs were identified in carbapenem-non-susceptible isolates. Two high-risk clones, ST235 (N=41) and ST111 (N=20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metallo-β-lactamase (MBL) genes, (N=38), (N=3), and (N=2), were detected. was detected in clonal complex 235 isolates. Two ST773 isolates carried and . Frameshift mutations in were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene-negative isolates.
Frameshift mutations in combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in . Further attention is required to curb the emergence and spread of new carbapenem-resistant clones.
耐碳青霉烯肠杆菌属在全球范围内是一个严重的健康问题。我们研究了来自韩国三家医院的耐碳青霉烯肠杆菌属分离株的克隆分布及其与碳青霉烯类耐药机制的关系。
共分析了 2011 年至 2019 年间收集的 155 株耐碳青霉烯肠杆菌属分离株的序列型 (STs)、抗菌药物敏感性和碳青霉烯类耐药机制，包括碳青霉烯酶的产生、耐药基因的存在、OprD 突变和 AmpC β-内酰胺酶的过度产生。
在耐碳青霉烯肠杆菌属分离株中鉴定出 60 个 STs。两种高风险克隆，ST235（N=41）和 ST111（N=20）占主导地位；然而，散发性 STs 比高风险克隆更为普遍。对阿米卡星的耐药率最低（49.7%），而对哌拉西林的耐药率最高（92.3%）。在 155 株耐碳青霉烯肠杆菌属分离株中，43 株（27.7%）产生碳青霉烯酶。检测到 3 种金属β-内酰胺酶 (MBL) 基因， （N=38）， （N=3）和 （N=2）。克隆复合体 235 分离株中检测到 。两个 ST773 分离株携带 和 。所有检测的分离株均存在 基因的框移突变，无论是否存在 MBL 基因。在 MBL 基因阴性的分离株中检测到 AmpC 的过度产生。
基因的框移突变与 MBL 的产生或 AmpC 的过度产生共同导致耐碳青霉烯肠杆菌属对碳青霉烯类的耐药。需要进一步关注以遏制新的耐碳青霉烯肠杆菌属克隆的出现和传播。
