检验医学 ›› 2026, Vol. 41 ›› Issue (6): 590-596.DOI: 10.3969/j.issn.1673-8640.2026.06.011

• 论著 • 上一篇    下一篇

2018—2024年上海市某二级综合医院高黏液表型肺炎克雷伯菌临床分离株分子特征、毒力基因和耐药性变迁

蔡骁垚1, 程阳1, 金姝2, 冯一鸣1, 胡奕雯1, 张立1, 朱卿1, 张骥1, 闫佩毅1()   

  1. 1 上海市普陀区人民医院检验科上海 200060
    2 同济大学附属普陀人民医院中心实验室上海 200060
  • 收稿日期:2025-08-04 修回日期:2026-02-03 出版日期:2026-06-30 发布日期:2026-07-01
  • 通讯作者: 闫佩毅,E-mail:yanpeiyi.cvcv@aliyun.com
  • 作者简介:蔡骁垚,男,1990年生,硕士,主要从事临床微生物和免疫检验工作。
  • 基金资助:
    同济大学“医学+X”交叉研究项目(2025-0717-YB-01);上海市普陀区卫生健康系统科技创新项目(PTKSWS202105);上海市普陀区卫生健康系统科技创新项目(PTKWWS202412);江苏大学临床医学科技发展基金项目(2019jd002)

Molecular characteristics,virulence genes and drug resistance changes of clinical isolates of hypermucoviscous Klebsiella pneumoniae of a Grade 2 general hospital in Shanghai from 2018 to 2024

CAI Xiaoyao1, CHENG Yang1, JIN Shu2, FENG Yiming1, HU Yiwen1, ZHANG Li1, ZHU Qing1, ZHANG Ji1, YAN Peiyi1()   

  1. 1 Department of Clinical LaboratoryPutuo District People's Hospital of ShanghaiShanghai 200060, China
    2 Central LaboratoryPutuo People's Hospital,Tongji UniversityShanghai 200060, China
  • Received:2025-08-04 Revised:2026-02-03 Online:2026-06-30 Published:2026-07-01

摘要:

目的 了解上海市普陀区人民医院新型冠状病毒感染疫情前后临床分离高黏液表型肺炎克雷伯菌(hmKp)的分子特征、毒力基因和耐药性变迁,为临床抗hmKp提供参考。方法 收集2018年1月—2020年12月(疫情前)和2023年1月—2024年12月(疫情后)肺炎克雷伯菌临床分离株,通过拉丝实验筛选出hmKp。采用聚合酶链反应(PCR)检测hmKp荚膜血清型(K1、K2、K5、K20、K54和K57)和毒力基因(rmpArmpA2、iroNmagAiucAkfuallS),对hmKp进行多位点序列分型(MLST),结合体外药物敏感性试验结果评估其耐药性。比较疫情前后荚膜血清型、毒力基因、耐药性变化差异。结果 共检出64株hmKp,疫情前后检出率分别为14.16%、11.68%,均主要分离自呼吸道样本。疫情前后荚膜血清型分布变化显著,优势荚膜血清型从K20转变为K2,K57血清型由25.0%降至0。ST型别多样性增加,K2型以ST86为主,出现ST25等新亚型;疫情后毒力基因重组明显:iroN基因在K1、K2、K20血清型中从0增至100%,rmpA2基因在K1型中检出率达100%,iucA基因在K1、K2型中检出率为0。耐药率总体呈下降趋势,对头孢他啶(由18.75%降至9.38%)和左氧氟沙星(由18.75%降至6.25%)的耐药率降幅较大,对碳青霉烯类保持低耐药率(亚胺培南耐药率为6.25%)。结论 疫情后,hmKp呈血清型替代(K2型崛起)和毒力基因重组(iroN基因普适化)特征。K2型虽非传统高毒力血清型,但携带rmpA+rmpA2+iroN复合毒力基因簇,需警惕其临床风险,建议结合多指标而非单一血清型评估菌株毒力。

关键词: 高黏液表型肺炎克雷伯菌, 多位点序列分型, 荚膜血清型, 毒力基因, 上海

Abstract:

Objective To investigate the molecular characteristics,virulence genes and drug resistance of hypermucoviscous Klebsiella pneumoniae(hmKp) isolated clinically before and after the coronavirus disease 2019 pandemic in Putuo District People's Hospital of Shanghai,and to provide a reference for dealing with hmKp in clinical practice. Methods The clinical isolates of Klebsiella pneumoniae from January 2018 to December 2020(before the pandemic) and from January 2023 to December 2024(after the pandemic) were collected. Positive isolates of hmKp were screened out through latex agglutination test. The capsular serotypes(K1,K2,K5,K20,K54 and K57) and virulence genes(rmpArmpA2,iroNmagAiucAkfu and allS) of hmKp were determined by polymerase chain reaction(PCR). Multilocus sequence typing(MLST) was performed on the hmKp isolates,and their drug resistance was evaluated through in vitro drug susceptibility test. The capsular serotypes,virulence genes and drug resistance before and after the pandemic were compared. Results Totally,64 isolates of hmKp were determined. The determination rate of hmKp was 14.16% before the pandemic,and it was 11.68% after the pandemic. The isolates mainly were collected from respiratory tract samples. The distribution of capsular serotypes showed significant changes before and after the pandemic,with the dominant serotype shifting from K20 to K2,and the K57 serotype decreased from 25.0% to 0. The ST type diversity of hmKp had increased,with the K2 type mainly being ST86,and new subtypes such as ST25 had emerged. After the pandemic,the recombination of virulence genes was significant:iroN increased from 0 to 100% in K1,K2 and K20 types,rmpA2 reached 100% in K1 type,and iucA was completely lost in K1 and K2 types. The overall drug resistance rate decreased,with a significant reduction in cefotaxime(from 18.75% to 9.38%) and levofloxacin(from 18.75% to 6.25%),and the carbapenems maintained a low drug resistance rate(6.25% for imipenem). Conclusions It suggests that hmKp may exhibit characteristics of serotype substitution(rise of K2 type) and recombination of virulence genes(universalization of iroN) after the pandemic. Although the K2 type is not a traditional highly virulent serotype,it carries the rmpA+rmpA2+iroN complex virulence genes,and its clinical risk should be vigilant. It is recommended to assess the virulence potential of the isolates using multiple indicators rather than a single serotype.

Key words: Hypermucoviscous Klebsiella pneumoniae, Multilocus sequence typing, Capsular serotype, Virulence gene, Shanghai

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