Contamination and mobile colistin resistance gene analysis for Salmonella isolated from retail chickens in Ji'nan

LIU Chang; LI Nan; HU Yujie; KAN Haopeng; YANG Zhu; LI Fengqin; WEN Hongling; ZHAO Li

doi:10.13590/j.cjfh.2023.02.022

Zhongguo shipin weisheng zazhi (Feb 2023)

Contamination and mobile colistin resistance gene analysis for Salmonella isolated from retail chickens in Ji'nan

LIU Chang,
LI Nan,
HU Yujie,
KAN Haopeng,
YANG Zhu,
LI Fengqin,
WEN Hongling,
ZHAO Li

Affiliations

LIU Chang: Department of Microbiological Laboratory Technology, School of Public Health, Cheeloo College of Medicine, Shandong University, Key Laboratory of Infectious Disease Control and Prevention in Universities of Shandong, Shandong Ji’nan 250012, China
LI Nan: Key Laboratory of Food Safety Assessment of Ministry of Health, China National Center for Food Safety Assessment, Beijing 100021, China
HU Yujie: Key Laboratory of Food Safety Assessment of Ministry of Health, China National Center for Food Safety Assessment, Beijing 100021, China
KAN Haopeng: Department of Microbiological Laboratory Technology, School of Public Health, Cheeloo College of Medicine, Shandong University, Key Laboratory of Infectious Disease Control and Prevention in Universities of Shandong, Shandong Ji’nan 250012, China
YANG Zhu: Department of Microbiological Laboratory Technology, School of Public Health, Cheeloo College of Medicine, Shandong University, Key Laboratory of Infectious Disease Control and Prevention in Universities of Shandong, Shandong Ji’nan 250012, China
LI Fengqin: Key Laboratory of Food Safety Assessment of Ministry of Health, China National Center for Food Safety Assessment, Beijing 100021, China
WEN Hongling: Department of Microbiological Laboratory Technology, School of Public Health, Cheeloo College of Medicine, Shandong University, Key Laboratory of Infectious Disease Control and Prevention in Universities of Shandong, Shandong Ji’nan 250012, China
ZHAO Li: Department of Microbiological Laboratory Technology, School of Public Health, Cheeloo College of Medicine, Shandong University, Key Laboratory of Infectious Disease Control and Prevention in Universities of Shandong, Shandong Ji’nan 250012, China

DOI: https://doi.org/10.13590/j.cjfh.2023.02.022
Journal volume & issue: Vol. 35, no. 2
pp. 283 – 288

Abstract

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ObjectiveTo investigate the contamination of Salmonella in retail chickens in Ji’nan city from 2020 to 2021， and to explore the prevalence of the mobile colistin resistance gene （mcr） among these Salmonella isolates.MethodsFrom December 2020 to November 2021， 260 retail chicken samples were collected in Ji’nan City， and Salmonella was isolated and confirmed according to GB 4789.4—2016 “National food standard - Food microbiological examination： Salmonella”. Serotype identification and mcr gene screening were performed for all Salmonella isolates by polymerase chain reaction （PCR）. The drug resistance of mcr gene-positive strains was tested by micro-broth dilution method.ResultsA total of 61 in 260 retail chicken samples were positive for Salmonella detection with the contamination rate of 23.46% （61/260）. The highest contamination rate was 53.33% （32/60） for samples collected in autumn. One hundred and three Salmonella strains were isolated， 56 of which were Salmonella Enteritidis， accounting for 54.37% （56/103）. Two Salmonella Indiana， isolated from two separate chicken wing samples collected from different regions， were positive for mcr-1 gene， with a positive rate of 1.94% （2/103）. Antimicrobial susceptibility testing revealed that both of the two mcr-1-harboring Salmonella Indiana were multi-drug resistant， and one of them was concurrently resistant to all 12 categories of tested drugs， including carbapenems and polymyxins.ConclusionThere was a certain degree of Salmonella contamination in retail chickens in Jinan from 2020 to 2021， and the contamination rate of the samples collected in autumn was higher than in any other seasons. Salmonella Enteritidis was the predominant serotype. It should be of concern that a Salmonella isolate carried mcr-1 gene with severe multidrug resistance to both colistin and carbapenems， indicating that the surveillance for Salmonella in the whole chain of chicken production should be strengthened continuously， to provide important basic data for the prevention and control of foodborne diseases.

Published in Zhongguo shipin weisheng zazhi

ISSN: 1004-8456 (Print)
Publisher: The Editorial Office of Chinese Journal of Food Hygiene
Country of publisher: China
LCC subjects: Technology: Chemical technology: Food processing and manufacture; Technology: Home economics: Nutrition. Foods and food supply
Website: http://www.zgspws.com/zgspwszzen/home

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