Molecular Evidence for Intra- and Inter-Farm Spread of Porcine mcr-1-Carrying Escherichia coli in Taiwan

Frontiers in Microbiology

Ming-Tang Chiou¹  Chao-Nan Lin¹  Chih-Cheng Lai²  Po-Ren Hsueh³  Yu-Tsung Huang⁴  Shun-Chung Hsueh⁵  Chun-Hsing Liao⁶ 

[1] Animal Disease Diagnostic Center, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan;Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung City, Taiwan;Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan;Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan;Department of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan;Department of Medicine, National Yang-Ming University, Taipei, Taiwan;Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan;Division of Infectious Diseases, Far Eastern Memorial Hospital, New Taipei City, Taiwan;

关键词: Escherichia coli;    sick pigs;    colistin resistance;    mcr-1;    genotypes;   

DOI  :  10.3389/fmicb.2020.01967

来源: DOAJ

【 摘 要 】

From January 2013 to December 2018, 90 Escherichia coli isolates were collected from 90 sick pigs on 58 farms in seven cities in Taiwan. The minimum inhibitory concentrations (MICs) of the isolates to 14 antimicrobial agents were determined on the VITEK 2 system (bioMérieux, Marcy-l’Etoile, France), and the resistance to colistin was assessed via the reference broth microdilution (BMD) method. The mobilized colistin resistance genes (mcr) were determined for the colistin-resistant isolates, which displayed BMD MICs ≥ 4 mg/L. Genotypes of the mcr-positive E. coli isolates were determined by multilocus sequence typing, arbitrarily primed polymerase chain reaction (PCR), and pulsed-field gel electrophoresis. All of the isolates were tested for susceptibility to carbapenems. Fifty isolates (55.6%) were resistant to colistin, 39 of which (78%) were positive for the mcr-1 gene. E. coli isolates harboring mcr-1 were most frequent in 2017 (15/18, 83.3%), followed by 2018 (13/23, 56.5%), 2015 (7/21, 33.3%), and 2016 (3/24, 12.5%). A total of 18 sequence types (STs) were identified among the 39 porcine mcr-1-carrying E. coli isolates; 13 were ST2521 (33.3%) isolated in 2017 and 2018. Five genotypes (clones) were identified, and the same genotypes were in sick pigs on the same farm and different farms. This suggests intra- and inter-farm spread of porcine mcr-1-carrying E. coli. The results presented here indicate high colistin resistance and wide mcr-1 E. coli prevalence among the sick pigs sampled in 2015–2018 in different regions of Taiwan.

【 授权许可】

Unknown