Effect of Dietary Copper on Intestinal Microbiota and Antimicrobial Resistance Profiles of Escherichia coli in Weaned Piglets

Yiming Zhang; Jian Zhou; Zhenglin Dong; Guanya Li; Jingjing Wang; Yikun Li; Dan Wan; Huansheng Yang; Yulong Yin

doi:10.3389/fmicb.2019.02808

Effect of Dietary Copper on Intestinal Microbiota and Antimicrobial Resistance Profiles of Escherichia coli in Weaned Piglets

Front Microbiol. 2019 Dec 17:10:2808. doi: 10.3389/fmicb.2019.02808. eCollection 2019.

Authors

Yiming Zhang^{1

2}, Jian Zhou², Zhenglin Dong^{1

2}, Guanya Li^{1

2}, Jingjing Wang², Yikun Li², Dan Wan², Huansheng Yang¹, Yulong Yin^{1

2}

Affiliations

¹ Hunan International Joint Laboratory of Animal Intestinal Ecology and Health, Laboratory of Animal Nutrition and Human Health, College of Life Sciences, Hunan Normal University, Changsha, China.
² Hunan Province Key Laboratory of Animal Nutritional Physiology and Metabolic Process, Key Laboratory of Agro-ecological Processes in Subtropical Region, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, China.

Abstract

Copper is an essential microelement for animals, and not only it has been used as a feed additive at pharmacological doses in swine production to improve growth performance, but it also has an effect on intestinal microbes by enhancing host bacterial resistance. However, there are few reports on the effects of pharmacological doses of copper on intestinal microorganisms and the antimicrobial resistance profiles of pathogenic bacteria, such as Escherichia coli, in pigs. Therefore, this study aimed to investigate the effects of pharmacological doses of copper on the microbial communities in the hindgut and the antimicrobial resistance profiles of E. coli in weaned piglets. Twenty-four healthy weaned piglets aged 21 ± 1 days and with an average weight of 7.27 ± 0.46 kg were randomly divided into four groups. The control group was fed a basal diet, while the treatment groups were fed a basal diet supplemented with 20, 100, or 200 mg copper/kg feed, in the form of CuSO₄. Anal swabs were collected at 0, 21, and 42 days of the trial, and E. coli was isolated. Meanwhile, the contents of the ileum and cecum from the control and 200 mg copper/kg feed groups were collected at 21 and 42 days for microbial community analysis and E. coli isolation. All isolated E. coli strains were used for antimicrobial resistance profile analysis. A pharmacological dose of copper did not significantly change the diversity, but significantly affected the composition, of microbial communities in the ileum and cecum. Moreover, it affected the microbial metabolic functions of energy metabolism, protein metabolism, and amino acid biosynthesis. Specifically, copper treatment increased the richness of E. coli in the hindgut and the rates of E. coli resistance to chloramphenicol and ciprofloxacin. Moreover, the rate of E. coli resistance to multiple drugs increased in the ileum of pigs fed a pharmacological dose of copper. Thus, a pharmacological dose of copper affected the composition of the microbial community, increased the antimicrobial resistance rates of intestinal E. coli, and was most likely harmful to the health of piglets at the early stage after weaning.

Keywords: Escherichia coli; antimicrobial resistance; copper; microbial community; piglet.