Mechanisms of resistance to ceftazidime/avibactam of carbapenem-resis-tant Klebsiella pneumoniae
10.12138/j.issn.1671-9638.20245389
- VernacularTitle:耐碳青霉烯类肺炎克雷伯菌对头孢他啶/阿维巴坦耐药机制的研究
- Author:
Xi-Yuan CHEN
1
;
Zi-Ling WANG
;
Shuang SONG
;
Bo-Yin XU
;
Jing-Fang SUN
;
Shu-Long ZHAO
;
Hai-Quan KANG
Author Information
1. 徐州医科大学医学技术学院,江苏 徐州 221004
- Keywords:
Klebsiella pneumoniae;
carbapenemase;
mutation;
ceftazidime/vibactam;
carbapenem-resistant Klebsiella pneumoniae
- From:
Chinese Journal of Infection Control
2024;23(11):1365-1372
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae(CRKP),and reveal its mechanism of resistance to ceftazidime/avibactam(CZA).Methods CZA-re-sistant CRKP strains initially isolated from the Affiliated Hospital of Xuzhou Medical University from January 2021 to September 2023 were collected.The carriage of 5 carbapenemase genes(blaKPC,blaNDM,blaOXA,blaVIM,blaIMp)were detected with gene amplification method and colloidal gold method.The relative copy number and expression level of Klebsiella pneumoniae(KP)carbapenemase-producing KP(KPC-KP)was detected with real-time quantita-tive polymerase chain reaction(RT-qPCR),mutation sites of KPC mutation strains were analyzed with whole-ge-nome sequencing,and epidemic characteristics of CRKP and resistance mechanism to CZA were analyzed.Results A total of 73 CZA-resistant CRKP strains were isolated,with 37(50.68％)being KPC and NDM co-producing strains,33(45.21％)NDM-producing alone(23 strains producing NDM-5 and 10 strains producing NDM-1),and 3 KPC-producing alone.KP-2842 strain was identified as ST11-type KPC-33 variant,KP-2127 and KP-2189 strains produced KPC-2.Compared with KP ATCC BAA-1705,the copy number of blaKPC in these strains up-regulated by 1.04-3.86 fold,and the expression increased by 6.66-12.93 fold,respectively.Colloidal gold and PCR methods demonstrated good consistency and the ability to detect the enzyme co-producing and KPC-33 variant.Conclusion In this hospital,the resistance of CRKP to CZA is primarily mediated by the metalloenzyme NDM,with co-produc-tion of NDM and KPC being a characteristic of CRKP.High copy number and expression level of blaKPC-2 also con-tribute to CZA resistance.This study identified the KPC-33 variant for the first time in ST11-type CRKP in Jiangsu Province.
