Molecular characteristics and homology analysis of carbapenem-resistant Escherichia coli
10.19405/j.cnki.issn1000-1492.2022.04.013
- Author:
Jiaxiang Huang
1
,
2
;
Zhongxin Wang
3
;
Yaping Pan
3
;
Yuanhong Xu
3
Author Information
1. Dept of Clinical Laboratory，The First Affiliated Hospital of Anhui Medical University，Hefei 230022
2. Dept of Clinical Laboratory，The First Affiliated Hospital of USTC(Anhui Provincial Hospital) ，Hefei 230001
3. Dept of Clinical Laboratory，The First Affiliated Hospital of Anhui Medical University，Hefei 230022
- Publication Type:Journal Article
- Keywords:
Escherichia coli;
Carbapenemases;
homology;
molecular characteristics
- From:
Acta Universitatis Medicinalis Anhui
2022;57(4):574-578
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the resistance characteristics, carbapenemase genotypes and the homology of carbapenem-resistantEscherichia coli(CREC).
Methods:6 092Escherichia coliisolated from clinical specimens in The First Affiliated Hospital of Anhui Medical University were collected and 71 strains of CREC were selected. The identification and antimicrobial susceptibility test were carried out by Vitek-2 Compact. Confirmation of carbapenemase phenotype was performed by modified hodge test(MHT), modified carbapenem inactivation method(mCIM) and carbapenemase nordmann-poirel(Carba NP) test. Carbapenemase-encoding genes(blaKPC, blaNDM, blaVIM, blaIMP,etc.) were identified by PCR and positive amplification products were sequenced, and then analyzed by using BLAST programs. ERIC-PCR fingerprinting was used to determine the clonal relationship between the different strains.
Results:CREC strains were mainly distributed in intensive care unit(ICU) and burn department, and the source of specimens was mainly urine. The drug susceptibility results showed that the resistance rates of CREC to ciprofloxacin, levofloxacin and cotrimoxazole were all above 70%, and the resistance rates to amikacin and tobramycin were less than 50%. Among 71 CREC strains, the number of positive strains for MHT, mCIM and Carba NP were 45, 67 and 69, and the positive rates were 63.38%, 94.37% and 97.18%, respectively. Carbapenemase genes were detected in 43 CREC isolates, of which 34 strains(79.07%, 34/43) carried blaNDM, 9 strains(20.93%, 9/43) carried blaKPC-2. In addition, the rates of strains harbored blaNDM-1or blaNDM-5were 20.59%(7/34) and 79.41%(27/34), respectively. Other carbapenem genes such as blaIMP, blaVIMand blaOXA-48were not detected. According to the fingerprint of ERIC-PCR, CREC was divided into 19 genotypes A-S, and no dominant genotype was found.
Conclusion:Drug resistance rate of clinically isolated CREC in our hospital is high, showing multi-drug resistance. blaNDMis the main carbapenemase gene of CREC. The epidemic CREC in our hospital has high genetic diversity and the homology of CREC is dispersive.
- Full text:2025021809364362957耐碳青霉烯大肠埃希菌分子特征和同源性分析_黄家祥.pdf
