Research Institute of Clinical Pharmacy, Shantou University Medical College, Shantou, Guangdong 515041, China.
Department of Cell Biology and Genetics, Shantou University Medical College, Shantou 515041, China.
J Appl Microbiol. 2023 Jul 4;134(7). doi: 10.1093/jambio/lxad125.
This study aimed to investigate the high-resolution phenotypic and genotypic characterization of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains isolated from hospitalized patients to explore the resistance genes and mobile genetic elements (MGEs) involved in horizontal dissemination.
Between May and September 2021, a total of 216 ESBL-producing E. coli isolates were recovered from multiple departments. The identification of strains was performed using MALDI-TOF mass spectrometry and PCR, while antibiotic susceptibility testing was carried out using the Vitek 2 COMPACT system to determine resistance patterns, while PCR was used to detect different resistance genes and MGEs. In addition, a conjugation assay was performed to investigate the horizontal gene transfer of resistance genes. Selected isolates underwent whole-genome sequencing (WGS) using the Illumina MiSeq platform.
A total of 216 out of 409 E. coli isolates recovered from a tertiary hospital were observed to be ESBL-producing, giving a carriage rate of 52.8%, as determined by phenotypic screening. The most frequent sources of ESBL-producing E. coli isolates were urine (129/216, 59.72%) and blood (50/216, 23.14%). The most prevalent ESBL genes identified were blaCTX-M (60.18%), blaTEM (40.27%), and blaSHV (18.05%). Three E. coli isolates were found to carry the genes blaNDM, mcr-1, and fosA3 genes. The most prevalent MGEs were IS26 (95.37%), Int (87.03%), and IncFIB (76.85%). WGS analysis of eight MDR E. coli strains revealed that these isolates belonged to eight different sequence types (STs) and serotypes and were found to harbor multiple plasmid replicons and virulence factors.
This study highlights a high incidence of antibiotic resistance genes and MGEs associated with the dissemination of ESBLs and other resistance genes.
本研究旨在调查从住院患者中分离出的产超广谱β-内酰胺酶（ESBL）的大肠埃希菌的高分辨率表型和基因型特征，以探讨与水平传播相关的耐药基因和移动遗传元件（MGEs）。
2021 年 5 月至 9 月，从多个科室共分离出 216 株产 ESBL 的大肠埃希菌。使用 MALDI-TOF 质谱和 PCR 进行菌株鉴定，使用 Vitek 2 COMPACT 系统进行药敏试验以确定耐药模式，同时使用 PCR 检测不同的耐药基因和 MGEs。此外，还进行了接合试验以研究耐药基因的水平基因转移。选择的分离株使用 Illumina MiSeq 平台进行全基因组测序（WGS）。
从一家三级医院回收的 409 株大肠埃希菌中，有 216 株被鉴定为产 ESBL，表型筛选的携带率为 52.8%。产 ESBL 大肠埃希菌分离株的最常见来源是尿液（129/216，59.72%）和血液（50/216，23.14%）。鉴定出的最常见 ESBL 基因是 blaCTX-M（60.18%）、blaTEM（40.27%）和 blaSHV（18.05%）。有 3 株大肠埃希菌携带 blaNDM、mcr-1 和 fosA3 基因。最常见的 MGEs 是 IS26（95.37%）、Int（87.03%）和 IncFIB（76.85%）。对 8 株 MDR 大肠埃希菌的 WGS 分析表明，这些分离株属于 8 个不同的序列类型（STs）和血清型，并且携带多种质粒复制子和毒力因子。
本研究强调了与 ESBL 和其他耐药基因传播相关的抗生素耐药基因和 MGEs 的高发生率。
