Surveillance of antimicrobial resistance among Escherichia coli from chicken and swine, China, 2008-2015

•The first eight-year national surveillance of antimicrobial resistance in food animals.•Multi-drug resistance was highly prevalent in E. coli.•These E. coli isolates showed high resistant rate (>80%) to several old drugs, including ampicillin, tetracycline and sulfisoxazole.•Increasing resistance to colistin, florfenicol and ceftiofur was observed.•The E. coli isolates from different provinces had different resistance patterns.

The objective of this study was to investigate the antimicrobial resistance trend in Escherichia coli from food animals in China. During 2008-2015, a total of 15,130 E. coli were isolated from chicken and swine from seven provinces. The susceptibilities of these isolates to nine classes of antimicrobial agents were determined using broth microdilution susceptibility method. The findings of this study include: (1) multi-drug resistance was highly prevalent in E. coli; (2) these E. coli isolates showed high resistant rate (>80%) to several old drugs, including ampicillin, tetracycline and sulfisoxazole; (3) increasing resistance to colistin, florfenicol and ceftiofur was observed; (4) the E. coli isolates from different provinces had different resistance patterns. All these data highlight the rising problem of antimicrobial resistance. It is urgent to improve the management of animal production and enhance the proper use of antimicrobials in China as well as the other countries.