title: Presence and Antimicrobial Resistance of Escherichia coli in Ready-to-Eat Foods in Shaanxi, China.
abstract: The aim of this study was to determine the presence and characteristics of Escherichia coli in ready-to-eat (RTE) foods. A total of 300 RTE foods samples were collected in Shaanxi Province, People's Republic of China: 50 samples of cooked meat, 165 samples of vegetable salad, 50 samples of cold noodles, and 35 samples of salted boiled peanuts. All samples were collected during summer (in July to October) 2011 and 2012 and surveyed for the presence of E. coli . E. coli isolates recovered were classified by phylogenetic typing using a PCR assay. The presence of Shiga toxin genes 1 (stx1) and 2 (stx2) was determined for these E. coli isolates by PCR, and all isolates were analyzed for antimicrobial susceptibility and the presence of class 1 integrons. Overall, 267 (89.0%) RTE food samples were positive for E. coli : 49 cold noodle, 46 cooked meat, 150 salad vegetable, and 22 salted boiled peanut samples. Of the 267 E. coli isolates, 73.0% belong to phylogenetic group A, 12.4% to group B1, 6.4% to group B2, and 8.2% to group D. All isolates were negative for both Shiga toxin genes. Among the isolates, 74.2% were resistant to at least one antimicrobial agent, and 17.6% were resistant to three or more antimicrobial agents. Resistance to ampicillin (75.6% of isolates) and tetracycline (73.1% of isolates) was most frequently detected; 26.2% of E. coli isolates and 68.8% of multidrug-resistant E. coli isolates were positive for class 1 integrons. All isolates were sensitive to amikacin. Our findings indicate that RTE foods in Shaanxi were commonly contaminated with antibiotic-resistant E. coli , which may pose a risk for consumer health and for transmission of antibiotic resistance. Future research is warranted to track the contamination sources and develop appropriate steps that should be taken by government, industry, and retailers to reduce microbial contamination in RTE foods.
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Allah Bux
authors.initials: AB
authors.lastname: Baloch
authors.affiliation: Institute of Quality and Standard for Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, People's Republic of China.|State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, People's Republic of China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Feng
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Meili
authors.initials: M
authors.lastname: Xi
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wu
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Qinhao
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Jingsi
authors.initials: J
authors.lastname: Tang
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Xiangxiang
authors.initials: X
authors.lastname: He
authors.affiliation: Institute of Quality and Standard for Agro-Products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, People's Republic of China.|State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, People's Republic of China.
authors.forename: Yingping
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.|Sino-U.S. Joint Research Center for Food Safety, Northwest A&F University, Yangling, Shaanxi 72100, People's Republic of China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xia
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents; D002681:China; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000302:isolation & purification*; D005516:Food Microbiology; D008826:Microbial Sensitivity Tests; D010802:Phylogeny
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents
keywords: Antimicrobial susceptibility; Class 1 integron; Escherichia coli; Ready-to-eat food