Tadesse Daniel A, Li Cong, Mukherjee Sampa, Hsu Chih-Hao, Bodeis Jones Sonya, Gaines Stuart A, Kabera Claudine, Loneragan Guy H, Torrence Mary, Harhay Dayna M, McDermott Patrick F, Zhao Shaohua
1 Division of Animal and Food Microbiology , U.S. FDA, CVM, Laurel, Maryland.
2 Texas Tech University , Department of Animal and Food Science, Lubbock, Texas.
Microb Drug Resist. 2018 Sep;24(7):939-948. doi: 10.1089/mdr.2018.0206. Epub 2018 Aug 27.
In recent years, there have been increased reports on the detection of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and Salmonella strains from food-producing animals and animal products in the United States. We characterized 18 ESBL E. coli isolates from cattle (n = 5), chicken breast (n = 5), ground turkey (n = 6), ground beef (n = 1), and pork chops (n = 1) that were collected by the National Antimicrobial Resistance Monitoring System (NARMS) between 2011 and 2015. In vitro antimicrobial susceptibility testing was done against a panel of 14 antimicrobials followed by a secondary panel of 9 β-lactam agents. Whole-genome sequencing was used to characterize the resistome, plasmids, and the genetic structures of the ESBL genes. All ESBL-producing E. coli isolates were resistant to at least three antimicrobial classes and carried various bla genes. Most of the cattle and ground turkey isolates carried bla. In chicken breast isolates, bla was present as part of an ISEcp1 transposition unit carried on a plasmid that shares sequence similarity with the backbone structure of the IncI plasmid. Isolates carrying the bla and bla genes, widely distributed in human clinical isolates, were also isolated. To our knowledge, this is the first report of the widely distributed bla and bla in E. coli isolates from retail meat samples in the United States. Different insertional sequences were identified upstream of these bla, including ISEcp1, IS26, and IS903-D. CTX-M in E. coli from food animals and retail chicken breast were often present on plasmids with other resistance genes. Other resistance genes identified included aadA, strA, strB, aac(3)-IId, aac(3)-VIa, aph(3')-Ic, bla, bla, floR, sul1, sul2, catA1, tetA, tetB, dfrA, and qacE. These data describe the emergence of CTX-M-carrying E. coli isolates in food animals and animal products monitored by NARMS program.
近年来，在美国，有关从食用动物和动物产品中检测出产超广谱β-内酰胺酶（ESBL）的大肠杆菌和沙门氏菌菌株的报告有所增加。我们对2011年至2015年间由国家抗微生物药物耐药性监测系统（NARMS）收集的18株来自牛（n = 5）、鸡胸肉（n = 5）、火鸡肉末（n = 6）、牛肉末（n = 1）和猪排（n = 1）的产ESBL大肠杆菌分离株进行了特征分析。针对一组14种抗菌药物进行了体外抗菌药敏试验，随后针对一组9种β-内酰胺类药物进行了试验。使用全基因组测序来表征耐药组、质粒以及ESBL基因的遗传结构。所有产ESBL的大肠杆菌分离株对至少三类抗菌药物耐药，并携带各种bla基因。大多数牛和火鸡肉末分离株携带bla。在鸡胸肉分离株中，bla作为ISEcp1转座单元的一部分存在于一个质粒上，该质粒与IncI质粒的主干结构具有序列相似性。还分离出了携带在人类临床分离株中广泛分布的bla和bla基因的分离株。据我们所知，这是美国零售肉类样本中大肠杆菌分离株中广泛分布的bla和bla的首次报告。在这些bla的上游鉴定出了不同的插入序列，包括ISEcp1、IS26和IS903-D。来自食用动物和零售鸡胸肉的大肠杆菌中的CTX-M通常存在于带有其他耐药基因的质粒上。鉴定出的其他耐药基因包括aadA、strA、strB、aac(3)-IId、aac(3)-VIa、aph(3')-Ic、bla bla、floR、sul1、sul2、catA1、tetA、tetB、dfrA和qacE。这些数据描述了NARMS计划监测的食用动物和动物产品中携带CTX-M的大肠杆菌分离株的出现情况。
