辽宁部分地区生肉制品中小肠结肠炎耶尔森菌多位点序列分型及耐药分析

Multilocus sequence typing and drug resistance analysis of Yersinia enterocolitica in raw meat products in some areas of Liaoning Province

摘要:

【背景】小肠结肠炎耶尔森菌(Yersinia enterocolitica)是一种人兽共患病原细菌，在我国分布广泛，可引起多种肠道症状以及全身性疾病，对人类和动物的健康造成威胁。【目的】了解辽宁省内部分地区不同畜禽生肉来源的小肠结肠炎耶尔森菌耐药表型、耐药基因、毒力基因及多位点序列分型(multilocus sequence typing, MLST)特征。【方法】对辽宁省2018−2021年分离自市售生鸡肉、生猪肉和生牛肉三类食品样品的26株小肠结肠炎耶尔森菌进行药物敏感性试验和血清型鉴定，并通过全基因组测序技术进行遗传相关信息的分析。【结果】26株小肠结肠炎耶尔森菌对头孢唑啉(cefazolin, CFZ)的耐药程度最高，对多黏菌素E (polymyxin E, CT)全部中介耐药，对氯霉素(chloramphenicol, CHL)和庆大霉素(gentamicin, GEN)两种抗生素均为敏感。26株菌的毒力基因以ail⁻virF⁻yadA⁻ystA⁻ystB⁺型为主，存在一株ail⁺virF⁻yadA⁻ystA⁺ystB⁻基因型，来自猪肉样品。血清型以O:5为主，占比为84.6%，O:8和未分型的菌株占比均为7.7%。26株菌均携带CRP、rosA和rosB这3种相同的耐药基因，有14株携带vat(F)和blaA基因，2株携带qnrD基因。经MLST分析共获得21种ST型，其中ST150型、ST726型、ST848型、ST143型、ST820型各有2株，其余ST型各1株，同一聚类簇的ST型别，其毒力基因和耐药基因较一致。【结论】辽宁省不同生肉来源的小肠结肠炎耶尔森菌ST型分布较分散，携带多种耐药基因，存在一定的耐药风险。

Abstract:

[Background] Yersinia enterocolitica is a zoonotic bacterium with wide distribution in China and can cause a variety of intestinal symptoms and systemic diseases, posing a threat to human and animal health. [Objective] To understand the drug resistance phenotypes and genes, virulence genes, and multilocus sequence typing of Y.enterocolitica isolated from different raw meat sources in Liaoning Province. [Methods] A total of 26 strains of Y.enterocolitica were isolated from raw chicken, raw pork, and raw beef samples in Liaoning Province from 2018 to 2021. The drug sensitivity test and serotyping were carried out, and whole genome sequencing was conducted to reveal the genetic information of the strains. [Results] The 26 strains of Y.enterocolitica had the highest resistance to cefazolin. All the 26 strains were intermediately resistant to polymyxin E and sensitive to chloramphenicol and gentamicin. The virulence genes of the 26 strains were mainly ail⁻virF⁻yadA⁻ystA⁻ystB⁺, and there was a strain with the genotype of ail⁺virF⁻yadA⁻ystA⁺ystB⁻, which was from a pork sample. Most of the strains presented the serotype of O:5, accounting for 84.6%, and the strains with the serotype of O:8 and unserotyped accounted for 7.7%. All the 26 strains carried the same resistance genes of CRP, rosA, and rosB. Fourteen strains carried vat(F) and blaA, and 2 strains carried qnrD. A total of 21 sequence types (ST) were obtained by multilocus sequence typing, of which ST150, ST726, ST848, ST143, and ST820 each had two strains, and the remaining STs each had one strain. The STs of the same cluster had the same virulence genes and drug resistance genes. [Conclusion] The STs of Y.enterocolitica from different raw meat samples in Liaoning Province present scattered distribution and carry multiple drug resistance genes, posing a risk of drug resistance.