Epidemiological distribution and genetic characterization of the colistin resistance gene mcr-1 in avian-origin enteroaggregative Escherichia coli
- Author:
LIU Mingxiang
;
ZHANG Jing
;
WANG Shan
- Publication Type:Journal Article
- Keywords:
Raw poultry meat;
enteroaggregative Escherichia coli;
mcr-1;
drug resistance;
whole genome sequencing
- From:
China Tropical Medicine
2024;24(11):1363-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To understand the contamination status and distribution of Escherichia coli in frozen raw poultry meat in Hongkou District, Shanghai,from February to November 2023, as well as the genetic characterization of colistin resistance gene mcr-1. Methods A total of 100 samples of different kinds of raw poultry meat, such as chicken, duck, and pigeon, were randomly collected from four types of venues including farmers' markets, stores, restaurants, and online stores in Hongkou District of Shanghai from February to November 2023. These samples were used for the isolation and culture of diarrheagenic Escherichia coli. Micro broth dilution method was used to conduct the drug susceptibility experiments, and real-time fluorescence quantitative PCR was adopted to detect mcr-1 resistance genes. Whole-genome sequencing was carried out to explore the resistance genes, plasmid type, and multilocus sequence typing (MLST) of mcr-1 positive strains. Phylogenetic trees of the core genome of the strain and MCR-1 protein were constructed based on single-copy genes and the maximum likelihood method, respectively. The data was analyzed by IBM SPSS Statistics 25.0 software. Results Among 100 raw poultry meat samples, diarrheagenic Escherichia coli was detected in 29 samples, and all of them were identified as enteroaggregative Escherichia coli (EAEC), with an overall detection rate of 29.0% (29/100). The highest detection rate was observed in restaurants (53.3%, 8/15). Among them, two strains (6.9%, 2/29) of chicken-origin EAEC carried mcr-1 resistance genes, both of which were multidrug-resistant strains producing extended-spectrum beta-lactamases (ESBLs), with 100.0% resistance to ciprofloxacin, nalidixic acid, ampicillin, cefotaxime, cefazolin, tetracycline, gentamicin, and polymyxin. Additionally, they carried various resistance genes including blaCTX-M-55, blaCTX-M-14, blaTEM-1, qnrS1, tet(A), tet(M), sul1, sul2, fosA3, aadA2, aac(3)-IVa, aac(3)-IId, aph(4)-Ia, mph(A) and mrx. MLST analysis showed that the ST types of two positive strains belonged to ST69 and ST156, respectively, with plasmids carrying mcr-1 of InCHI2 type. Core group genome analysis of the two avian-derived E.coli strains found high similarity to human-derived E.coli_042 (GCA_000027125) and E.coli_SE11 (GCA_000010385). The MCR-1 protein showed high phylogenetic similarity to avian-origin MCR-1 proteins reported from other countries. Conclusions The contamination of raw poultry meat with EAEC in Hongkou District is serious, with most of the isolated strains exhibiting multidrug resistance. The molecular surveillance of antibiotic resistance genes with public health significance such as mcr-1 should be continuously carried out in frozen raw poultry to control the development of resistance.
- Full text:202511121010556152511.Epidemiological distribution and genetic characterization of the colistin resistance gene mcr-1 in avian-origin enteroaggregative Escherichia coli.pdf
