title: Characterization of extended-spectrum beta-lactamases-producing Salmonella strains isolated from retail foods in Shaanxi and Henan Province, China.
abstract: Extended-spectrum beta-lactamases (ESBL)-producing Salmonella enterica have been reported worldwide. However, research on foodborne ESBL-producing Salmonella has been rarely conducted. One hundred and thirty eight ceftriaxone or/and cefoperazone-resistant Salmonella strains recovered from retail foods in Shaanxi and Henan Province, China, were screened for ESBL. The ESBL-producing strains were further characterized for antimicrobial resistance, pulse field gel electrophoresis (PFGE) profiles, and the presence of blaTEM, blaSHV, blaOXA, blaCTX-M, and blaPSE. The transferability of ESBL encoding genes to a susceptible Escherichia coli strain was also investigated. Thirty (21.7%) isolates were identified as ESBL positive and belonged to S. enterica serovars Indiana, Shubra, Typhimurium, and Enteritidis. S. Indiana and S. Shubra isolates were firstly identified in ESBL-producing strains. Great genetic diversity was seen among these ESBL-producing strains. Nucleotide sequence analysis revealed that blaTEM-1B was the only ESBL-encoding gene among the genes tested and was detected in 26 of 30 strains and was carried in the conjugative plasmids. The blaTEM-1B gene was transferable through conjugation at rates ranging from 4.71 × 10(-7) to 7.55 × 10(-6) transconjugant per recipient cell. This study provides the evidence of foodborne ESBL-producing Salmonella, and the transferability of plasmid harboring ESBL-encoding genes could possibly contribute to the dissemination of ESBL.
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Baowei
authors.initials: B
authors.lastname: Yang
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Qianning
authors.initials: Q
authors.lastname: Wang
authors.affiliation: National Institutes for Food and Drug Control, Beijing 100050, China.
authors.forename: Shenghui
authors.initials: S
authors.lastname: Cui
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Shi
authors.affiliation: Northwest A&F University, Shaanxi 712100, China. Electronic address: foodscixiaodong@yahoo.com.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Xia
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Meili
authors.initials: M
authors.lastname: Xi
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Shanghai Jiaotong University, Shanghai 200240, China.
authors.forename: Xianming
authors.initials: X
authors.lastname: Shi
authors.affiliation: Shanghai Jiaotong University, Shanghai 200240, China.
authors.forename: Dapeng
authors.initials: D
authors.lastname: Wang
authors.affiliation: Northwest A&F University, Shaanxi 712100, China.
authors.forename: Zengfeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Northwest A&F University, Shaanxi 712100, China; Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA; Joint Institute for Food Safety and Applied Nutrition, College Park, MD 20742, USA.
authors.forename: Jianghong
authors.initials: J
authors.lastname: Meng
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002645:Chickens; D002681:China; D003227:Conjugation, Genetic; D016521:Electrophoresis, Gel, Pulsed-Field; D005399:Fishes; D005506:Food Contamination / Q000032:analysis; D022761:Gene Transfer, Horizontal; D008460:Meat / Q000382:microbiology*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D012475:Salmonella / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D013552:Swine; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases
keywords: Antimicrobial resistance; Extended-spectrum beta-lactamases; Foodborne Salmonella