三株致肝脓肿高毒力肺炎克雷伯菌的生物学特性及基因特征分析  

Biological and genetic characteristics of three hypervirulent Klebsiella pneumoniae strains causing liver abscess

作　　者：张域琪 王娟[2] 韩蕾 黎璞 马文涛 张春[5] 李雅丽 袁晶 雷金娥[1] ZHANG Yuqi;WANG Juan;HAN Lei;LI Pu;MA Wentao;ZHANG Chun;LI Yali;YUAN Jing;LEI Jin’e(Department of Laboratory Medicine,The First Affiliated Hospital of Xi’an Jiaotong University,Xi’an 710061;College of Veterinary Medicine,Northwest A&F University,Yangling 712100;Department of Microbiology and Immunology,School of Basic Medicine,Xi’an Jiaotong University Health Science Center,Xi’an 710061;Department of Critical Care Medicine,The Second Affiliated Hospital of Air Force Medical University,Xi’an 710038;Surgical Intensive Care Unit,The First Affiliated Hospital of Xi’an Jiaotong University,Xi’an 710061,China)

机构地区：[1]西安交通大学第一附属医院检验科,陕西西安710061 [2]西北农林科技大学动物医学院,陕西杨凌712100 [3]西安交通大学医学部基础医学院病原生物学与免疫学系,陕西西安710061 [4]空军军医大学唐都医院重症医学科,陕西西安710038 [5]西安交通大学第一附属医院外科ICU,陕西西安710061

出　　处：《西安交通大学学报（医学版）》2024年第6期885-894,共10页Journal of Xi’an Jiaotong University（Medical Sciences）

基　　金：西安交通大学第一附属医院临床研究项目(No.XJT1AF-CRF-2019-015);陕西省自然科学基础研究计划项目(No.2024JC-YBMS-732)。

摘　　要：目的了解引起化脓性肝脓肿(pyogenic liver abscess,PLA)的高毒力肺炎克雷伯菌(Hypervirulent Klebsiella pneumoniae,hvKp)的耐药机制、毒力特征及致病作用,同时为该细菌临床抗感染治疗提供相关数据。方法收集3株在西安交通大学第一附属医院不同科室肝脓肿患者肝脏脓肿液中分离出的肺炎克雷伯菌,用拉丝试验确定其高毒表型;VITEK 2 Compact全自动微生物分析系统进行药敏试验;全基因组测序技术确定其荚膜血清型、多位点序列分型(MLST)、毒力基因与耐药基因等分子特征;建立小鼠感染模型进行致病性试验。结果分离菌株黏性较大,黏液丝牵拉长度>5 mm,均为高黏液表型;除146007为多重耐药菌外,其余2株菌的抗生素敏感性较高;其全基因组序列测定显示,分离菌株均为高毒力型,携带毒素质粒rmpADC/rmpA2,铁摄取系统、菌毛及分泌系统等多种毒力因子,3株分离株均为rmpA/rmpA2合并iucA/iutA阳性,可判定为hvKp;检测到多种耐药基因,如β-内酰胺酶基因blaTEM、blaSHV和blaCTX-M等;分离菌株对小鼠有较强致病性,剖检死亡小鼠可见其各器官均有不同程度病变。结论本文分离出的3株hvKp携带多种耐药基因与毒力基因且致病性较强,提示实验室和临床应及时识别并采取必要的处置策略,防止hvKp进一步扩散。Objective To understand the resistance mechanisms,virulence characteristics,and pathogenicity of hypervirulent Klebsiella pneumoniae(hvKp),which causes pyogenic liver abscess(PLA),and to provide related data for clinical treatment of infection caused by this type of bacteria.Methods We collected three strains of Klebsiella pneumoniae isolated from the liver abscess fluid of patients with liver abscesses in various departments of The First Affiliated Hospital of Xi’an Jiaotong University.The hypervirulent phenotypes were determined by the wire test,and drug sensitivity was assessed using the VITEK 2 compact automatic microbiological analyzer.Molecular characteristics such as podocarp serotypes,multi-locus sequence typing(MLST),virulence genes,and drug resistance genes were identified through whole-genome sequencing.Additionally,a mouse infection model was established to evaluate pathogenicity.Results The isolates were sticky,with mucous thread pulling length>5 mm,all of which exhibited high viscosity phenotypes.Except 146007,which is a multidrug-resistant bacterium,the other two strains had higher antibiotic sensitivity.Whole genome sequencing revealed that the isolates were of high-virulence type,carrying the toxin plasmid rmpADC/rmpA2,iron uptake system,bacterial hairs,secretion system,and other virulence factors.All the three isolates tested positive for rmpA/rmpA2 combined with iucA/iutA,indicating they could be classified as hvKp.Multiple resistance genes were detected,such asβ-lactamase like bla TEM,bla SHV,and bla CTX-M.The isolates were highly pathogenic to mice,as evidenced by the diseased organs of the deceased mice observed on autopsy.Conclusion The three strains of hvKp isolated in this study carried multiple drug-resistant genes and were highly pathogenic,which suggests that in laboratories and clinical practices it is imperative to promptly identify and adopt necessary disposal strategies to prevent further spread of hvKp.

关 键 词：高毒力肺炎克雷伯菌(hvKp) 全基因组测序 耐药性 高毒力菌株 小鼠感染模型 

分 类 号：R378.996[医药卫生—病原生物学]