Cao Shuaijun, Jiang Xiaoying, Suo Jinshan, Lu Yanyan, Ju Mohan, Zeng Qixiang, Zheng Qingru, Zhang Zuoyan, Tang Wenqi
Department of Critical Care Medicine, Shanghai Sixth People's Hospital, Shanghai, People's Republic of China.
Institute of Antibiotics, Huashan Hospital, Fudan University, Shanghai, People's Republic of China.
Infect Drug Resist. 2024 Jan 26;17:319-327. doi: 10.2147/IDR.S444117. eCollection 2024.
Carbapenem-Resistant Enterobacteriaceae (CRE) has posed a significant threat to humans.The aim of this study was to investigate the molecular characteristics of -producing in a university-affiliated tertiary hospital.
Polymerase chain reaction (PCR) and BLAST+ software were used to detect the prevalence of in and . Whole-genome sequencing was performed for the -harboring clinical isolates. Antimicrobial resistance genes, MLSTs, KPC-carrying plasmid typing and genetic environment of were analyzed. A maximum likelihood core single nucleotide polymorphism (SNP)-based phylogeny tree was constructed to determine the evolutionary relationships within this ST131 collection. Conjugation experiments were performed to determine the mobilization of . The minimal inhibitory concentrations of the common antimicrobial agents were determined using the broth microdilution method.
The prevalence of in 424 clinical isolates and 1636 strains from GenBank database were 2.2% (45/2060) whereas the detection rate of in from the GenBank database was 29.8% (415/1394). The -harboring conjugants exhibited resistance to multiple β-lactams, except for cefepime-zidebactam and ceftazidime-avibactam. All -carring isolates were susceptible to tigecycline and polymyxin B. ST131 was the dominant sequence type of -carring , accounting for 40.0% (18/45). Most of the -producing ST131 (89.5%,17/19) belonged to clade C ST131 lineage. Genetic environment analysis revealed that 57.8% (26/45) of gene was linked to Tn-associated structure IS-IS. IncN was the most common plasmid type in KPC-producing whereas IncFII was the dominant plasmid type in KPC-producing
The detection rate of was lower in compared with e. The dominant sequence and plasmid types of -harboring isolates differed between and . Further studies about the role of the defense system in acquisition of KPC-plasmids in will be performed to provide new insights into the low prevalence of .
耐碳青霉烯类肠杆菌科细菌（CRE）对人类构成了重大威胁。本研究旨在调查某大学附属医院产KPC的肠杆菌科细菌的分子特征。
采用聚合酶链反应（PCR）和BLAST+软件检测肠杆菌科细菌和肺炎克雷伯菌中KPC的流行情况。对携带KPC的临床分离株进行全基因组测序。分析耐药基因、多位点序列分型（MLST）、携带KPC的质粒分型及KPC的基因环境。构建基于最大似然核心单核苷酸多态性（SNP）的系统发育树，以确定该ST131菌株集合内的进化关系。进行接合实验以确定KPC的转移性。采用肉汤微量稀释法测定常见抗菌药物的最低抑菌浓度。
424株临床肠杆菌科细菌分离株和GenBank数据库中1636株肺炎克雷伯菌菌株中KPC的流行率为2.2%（45/2060），而GenBank数据库中肺炎克雷伯菌KPC的检出率为29.8%（415/1394）。携带KPC的接合子除对头孢吡肟-他唑巴坦和头孢他啶-阿维巴坦外，对多种β-内酰胺类药物耐药。所有携带KPC的分离株对替加环素和多粘菌素B敏感。ST131是携带KPC的肠杆菌科细菌的主要序列类型，占40.0%（18/45）。大多数产KPC的ST131肠杆菌科细菌（89.5%，17/19）属于C进化枝ST131谱系。基因环境分析显示，57.8%（26/45）的KPC基因与Tn相关结构IS-IS相连。IncN是产KPC的肠杆菌科细菌中最常见的质粒类型，而IncFII是产KPC的肺炎克雷伯菌中占主导地位的质粒类型。
与肺炎克雷伯菌相比，肠杆菌科细菌中KPC的检出率较低。携带KPC的分离株的主要序列和质粒类型在肠杆菌科细菌和肺炎克雷伯菌之间存在差异。将进一步研究防御系统在肠杆菌科细菌获取KPC质粒中的作用，以深入了解KPC低流行率的原因。
