title: Antimicrobial and disinfectant resistance of Escherichia coli isolated from giant pandas.
abstract: OBJECTIVE
  The study aims to demonstrate the antimicrobial and disinfectant resistance phenotypes and genotypes of Escherichia coli isolates obtained from giant pandas (Ailuropoda melanoleuca).
  
  
  RESULTS
  Antimicrobial testing was performed according to the standard disk diffusion method. The minimal inhibitory concentrations (MICs) of disinfectants were determined using the agar dilution method. All isolates were screened for the presence of antimicrobial and disinfectant resistance genes and further analysed for genetic relatedness by pulse-field gel electrophoresis (PFGE). Results showed that 46·6% of the isolates were resistant to at least one antimicrobial. Escherichia coli isolates showed resistance to fewer antimicrobials as panda age increased. Among antimicrobial-resistant E. coli isolates, the antimicrobial resistance genes blaCTX-M (88·2%) and sul1 (92·3%) were most prevalent. The disinfectant resistance genes emrE, ydgE/ydgF, mdfA and sugE(c) were commonly present (68·2-98·9%), whereas qac and sugE(p) were relatively less prevalent (0-21·3%). The frequencies of resistance genes tended to be higher in E. coli isolated in December than in July, and PFGE profiles were also more diverse in isolates in December. The qacEΔ1 and sugE(p) genes were higher in adolescent pandas than in any other age groups. PFGE revealed that antimicrobial resistance correlated well with sampling time and habitat.
  
  
  CONCLUSIONS
  This study demonstrated that antimicrobial and disinfectant resistance was common in giant panda-derived E. coli, and the antimicrobial resistance was associated with sampling time and habitat. Escherichia coli could serve as a critical vector in spreading disinfectant and antimicrobial resistance.
  
  
  CONCLUSIONS
  This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The study highlights the need for regularly monitoring the antimicrobial and disinfectant resistance in bacteria from giant pandas.
authors.affiliation: College of Resources and Environment, Sichuan Agricultural University, Chengdu, China.|The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: L
authors.initials: L
authors.lastname: Guo
authors.affiliation: College of Resources and Environment, Sichuan Agricultural University, Chengdu, China.|The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: M
authors.initials: M
authors.lastname: Long
authors.affiliation: The China Conservation and Research Center for Giant Panda, Sichuan, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.affiliation: College of Resources and Environment, Sichuan Agricultural University, Chengdu, China.|The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: G
authors.initials: G
authors.lastname: Wu
authors.affiliation: The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: W
authors.initials: W
authors.lastname: Deng
authors.affiliation: The China Conservation and Research Center for Giant Panda, Sichuan, China.
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.affiliation: The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: B
authors.initials: B
authors.lastname: Li
authors.affiliation: The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Meng
authors.affiliation: The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: L
authors.initials: L
authors.lastname: Cheng
authors.affiliation: The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: L
authors.initials: L
authors.lastname: Fan
authors.affiliation: The China Conservation and Research Center for Giant Panda, Sichuan, China.
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.affiliation: College of Resources and Environment, Sichuan Agricultural University, Chengdu, China.|The Laboratory of Microbiology, Dujiangyan Campus of Sichuan Agricultural University, Dujiangyan, Sichuan, China.
authors.forename: L
authors.initials: L
authors.lastname: Zou
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D006801:Humans; D008826:Microbial Sensitivity Tests; D001503:Ursidae / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D004202:Disinfectants
keywords: PFGE; antimicrobial; disinfectant; giant pandas; resistance genes