Department of Microbiology, Yongchuan Hospital of Chongqing Medical University, Chongqing, China.
Department of Microbiology, The First People's Hospital of Jingzhou City, Jingzhou, China.
Microb Drug Resist. 2020 Sep;26(9):1009-1018. doi: 10.1089/mdr.2019.0363. Epub 2020 Mar 4.
The aim of this study was to investigate the characteristics of carbapenem-resistant (CRKP) ST76 isolates collected during an outbreak in a hospital's intensive care unit and neurosurgery unit. Seventeen separate clinical isolates of CRKP were collected from patients from March 2016 to February 2017. Bacterial isolates were identified, and antimicrobial susceptibility testing was conducted using the VITEK-2 compact system. Isolates containing antibiotic resistance genes were characterized by polymerase chain reaction and DNA sequencing. Clonal relatedness was assessed by multilocus sequence typing and pulsed-field gel electrophoresis. Conjugation experiments were performed to determine the transferability of plasmids with antibiotic resistance. The genomic features and mobile genetic elements of ST76 CRKP were detected by whole genome sequencing. ST76 KPC-2-producing CRKP prevailed in our hospital, causing an outbreak. The strains also carried , , , , and resistance genes. Plasmids from 17.7% of the isolated strains bearing these resistance genes could be transferred into the recipient J53 through conjugation. Sequencing results showed that the KP4 genome mainly consisted of a circular chromosome and three antibiotic resistance plasmids. The plasmid carrying the gene was located on a 437 kb IncFIB (pQil) plasmid with Tn--ΔT gene structure. Genes conferring resistance against aminoglycosides, quinolones, fluoroquinolones, beta-lactamase, phenicols, sulfonamides, and trimethoprims and the presence of virulence-associated genes related to iron acquisition or adhesins were determined. This is the first report of the whole genome sequence of a KPC-2-producing ST76 isolate. This work provides a basis for understanding antibiotic resistance and resistant plasmid transmission. Relevant departments should implement infection control and prevention measures to reduce the incidence of nosocomial infections.
本研究旨在调查医院重症监护病房和神经外科病房发生的爆发中分离出的耐碳青霉烯肠杆菌科（CRKP）ST76 菌株的特征。从 2016 年 3 月至 2017 年 2 月，从患者中收集了 17 株单独的 CRKP 临床分离株。使用 VITEK-2 compact 系统对细菌分离株进行鉴定和药敏试验。通过聚合酶链反应和 DNA 测序鉴定含有抗生素耐药基因的分离株。通过多位点序列分型和脉冲场凝胶电泳评估克隆相关性。进行接合实验以确定具有抗生素耐药性的质粒的可转移性。通过全基因组测序检测 ST76 CRKP 的基因组特征和移动遗传元件。产 KPC-2 的 ST76 CRKP 在我院流行，引起暴发。这些菌株还携带 blaCTX-M-15、blaOXA-48、blaDHA-1、blaVEB-1、blaGES 和 blaIMP 耐药基因。17.7%的携带这些耐药基因的分离株携带的质粒可通过接合转移到受体 J53 中。测序结果表明，KP4 基因组主要由一个圆形染色体和三个抗生素耐药质粒组成。携带 基因的质粒位于一个 437kb IncFIB（pQil）质粒上，具有 Tn--ΔT 基因结构。基因赋予对抗生素氨基糖苷类、喹诺酮类、氟喹诺酮类、β-内酰胺酶、苯氧乙酸类、磺胺类和甲氧苄啶的耐药性，以及与铁摄取或黏附素相关的毒力相关基因的存在。这是首例 KPC-2 产 ST76 分离株全基因组序列的报道。这项工作为了解抗生素耐药性和耐药质粒的传播提供了基础。相关部门应实施感染控制和预防措施，以降低医院感染的发生率。
