摘要
为了解冷冻食品中大肠杆菌污染情况,分析其潜在的食品安全问题,从陕西省4市(宝鸡、咸阳、西安和渭南)共收集冷冻食品样品360份(120份速冻水饺和240份冰淇淋)。通过选择培养和聚合酶链式反应(polymerase chain reaction,PCR)进行大肠杆菌分离鉴定。然后对分离株进行21种毒力基因、23种耐药基因、15种抗生素耐药性检测及种群分型。360份样品中大肠杆菌污染率为13.6%(49/360),其中5份样品(10.2%,5/49)大肠菌群计数超过100 CFU/g。21种被检毒力基因中有9种毒力基因被检出,以肠外致病性大肠杆菌相关基因FyuA和iss的检出率最高(均为14.3%,7/49)。药敏结果显示,菌株对β-内酰胺类抗生素和叶酸代谢抑制剂的耐药最为普遍(均为98.0%,48/49),其次为四环素(20.4%,10/49)。其中β-内酰胺类主要编码基因为blaCTX,四环素主要编码基因为tetA。研究还发现1株分离株携带多黏菌素类抗性基因mcr-9。此外,20.4%的菌株为多重耐药菌株,最多可对13种抗生素耐药。所有分离株共有4种系统发育群(A、B1、C和F),A群为优势群系(63.3%,31/49)。综上,陕西省典型冷冻食品中存在致病性大肠杆菌及耐多药菌株污染,存在通过食物链传播给人的风险。
To investigate the level of Escherichia coli contamination in frozen foods in Shaanxi province,China,and analyze the potential food safety issues caused by it,a total of 360 frozen food samples(120 frozen dumpling samples and 240 ice cream samples)were collected from four cities(Baoji,Xianyang,Xi’an and Weinan)in Shaanxi province.E.coli strains were isolated and identified by selective culture and polymerase chain reaction(PCR).The 21 virulence genes,23 antibiotic resistance genes,resistance to 15 common antibiotics and phylogenetic groups of the isolates were investigated.Total 13.6%(49/360)of the 360 samples were contaminated with E.coli,of which five samples(10.2%,5/49)had coliform counts>100 CFU/g.Nine virulence genes were detected,among which the detection rate of the extraintestinal pathogenic E.colirelated genes FyuA and iss was the highest(14.3%,7/49 each).The results of drug susceptibility test showed that the isolates were most commonly resistant toβ-lactams and folate metabolism inhibitors(98.0%,48/49 each),followed by tetracyclines(20.4%,10/49).The major coding gene ofβ-lactams was blaCTX and the major coding gene of tetracyclines was tetA.This study also identified one isolate carrying the polymyxin resistance gene mcr-9.Moreover,20.4%of the strains were multi-drug resistant,and one of them was resistant to up to 13 antibiotics.Four phylogenetic groups(A,B1,C,and F)were detected in all isolates,and group A was the dominant one.The results indicate that there is a risk of the contamination of pathogenic E.coli and multidrug-resistant strains in frozen foods and their transmission to humans through the food chain in Shaanxi,China.
作者
徐旭
杨静
张鹏飞
张钰嘉
阮傅倩
王婷
李雯
万阳丽
常冠红
张瑶
王新
XU Xu;YANG Jing;ZHANG Pengfei;ZHANG Yujia;RUAN Fuqian;WANG Ting;LI Wen;WAN Yangli;CHANG Guanhong;ZHANG Yao;WANG Xin(College of Food Science and Engineering,Northwest A&F University,Yangling 712100,China;Yangling Quality and Technical Inspection Institute,Yangling 712100,China;College of Innovation and Experiment,Northwest A&F University,Yangling 712100,China;Sichuan Academy of Animal Sciences,Chengdu 610066,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2022年第14期280-288,共9页
Food Science
基金
国家自然科学基金面上项目(31871894)
国家自然科学基金联合基金项目(U1703119)
陕西省重点研发计划项目(2021SF-470)。
关键词
冷冻食品
大肠杆菌
毒力基因
种群分型
耐药性
frozen food
Escherichia coli
virulence gene
phylogenetic groups
antibiotic resistance
