title: Characteristics of extended-spectrum β-lactamase-producing Escherichia coli isolated from fecal samples of piglets with diarrhea in central and southern Taiwan in 2015.
abstract: BACKGROUND
  The production of extended-spectrum β-lactamases (ESBLs) confer resistance to the commonly used beta-lactam antimicrobials and ESBL-producing bacteria render treatment difficulty in human and veterinary medicine. ESBL-producing bacteria have emerged in livestock in recent years, which may raise concerns regarding possible transfer of such bacteria through the food chain. The swine industry is important in Taiwan, but investigations regarding the status of ESBL in swine are limited.
  
  
  RESULTS
  We collected 275 fecal swab samples from piglets with diarrhea in 16 swine farms located in central and southern Taiwan from January to December 2015 and screened them for ESBL-producing Escherichia coli. ESBL producers were confirmed phenotypically by combination disc test and genotypically by polymerase chain reaction and DNA sequencing. The occurrence rate of ESBL-producing E. coli was 19.7% (54 of 275), and all were obtained in swine farms located in southern Taiwan. blaCTX-M-1-groupand blaCTX-M-9-groupwere the two blaCTX-Mgroups found. blaCTX-M-55(34 of 54; 63.0%) and blaCTX-M-15(16 of 54; 29.6%), which belong to the blaCTX-M-1-group, were the two major bla gene types, whereas blaCTX-M-65was the only type found in the blaCTX-M-9 group. Twenty-seven strains contained blaTEM-1, and the other 27 strains contained blaTEM-116. One strain found in Pingtung harbored three bla genes: blaTEM-116, blaCTX-M-55, and blaCTX-M-65. ESBL-producing E. coli exhibited a multidrug-resistant phenotype, and multilocus sequence typing revealed that the ST10 clonal complexes, including ST10, 167, 44, and 617 accounted for 35% (19 of 54) of these strains.
  
  
  CONCLUSIONS
  ESBL-producing E. coli from piglets with diarrhea were isolated from swine farms located in southern Taiwan. The most commonly detected bla were blaCTX-M-15and blaCTX-M-55. The ST10 clonal complexes comprised most of our ESBL-producing E. coli strains. Fecal shedding from swine may contaminate the environment, resulting in public health concerns; thus, continued surveillance of ESBL is essential in swine and in other food animals.
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, 106, Taiwan.
authors.forename: Wan-Chen
authors.initials: WC
authors.lastname: Lee
authors.affiliation: Department of Veterinary Medicine, School of Veterinary Medicine, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, 106, Taiwan. ksyeh@ntu.edu.tw.|National Taiwan University Veterinary Hospital, Taipei, 106, Taiwan. ksyeh@ntu.edu.tw.
authors.forename: Kuang-Sheng
authors.initials: KS
authors.lastname: Yeh
mesh_terms: D000818:Animals; D003967:Diarrhea / Q000382:microbiology / Q000662:veterinary*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D013624:Taiwan; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D001618:beta-Lactamases
keywords: Escherichia coli; Extended spectrum β-lactamase; Multilocus sequence typing