Nationwide analysis of antimicrobial resistance in pathogenic Escherichia coli strains isolated from diseased swine over 29 years in Japan

Masahiro Kusumoto; Yukino Tamamura-Andoh; Yuna Hikoda-Kogiku; Asami Magome; Erina Okuhama; Keisuke Sato; Yoshino Mizuno; Nobuo Arai; Ayako Watanabe-Yanai; Taketoshi Iwata; Yoshitoshi Ogura; Yasuhiro Gotoh; Keiji Nakamura; Tetsuya Hayashi; Masato Akiba

doi:10.3389/fmicb.2023.1107566

Nationwide analysis of antimicrobial resistance in pathogenic Escherichia coli strains isolated from diseased swine over 29 years in Japan

Front Microbiol. 2023 Mar 17:14:1107566. doi: 10.3389/fmicb.2023.1107566. eCollection 2023.

Authors

Affiliations

¹ National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Japan.
² Graduate School of Veterinary Science, Osaka Metropolitan University, Osaka, Japan.
³ Ehime Chuyo Livestock Hygiene Service Center, Ehime, Japan.
⁴ Kagoshima Central Livestock Hygiene Service Center, Kagoshima, Japan.
⁵ Miyazaki Livestock Hygiene Service Center, Miyazaki, Japan.
⁶ Niigata Chuo Livestock Hygiene Service Center, Niigata, Japan.
⁷ Kumamoto Chuo Livestock Hygiene Service Center, Kumamoto, Japan.
⁸ Department of Infectious Medicine, Kurume University School of Medicine, Fukuoka, Japan.
⁹ Department of Bacteriology, Faculty of Medical Sciences, Kyushu University, Fukuoka, Japan.
¹⁰ School of Veterinary Medicine, Rakuno Gakuen University, Ebetsu, Japan.

Abstract

Pathogenic Escherichia coli strains are important causes of several swine diseases that result in significant economic losses worldwide. In Japan, the use of antimicrobials in swine is much higher than that in other farm animals every year. Antimicrobial resistance in pathogenic E. coli strains also heavily impacts the swine industry due to the limited treatment options and an increase in the potential risk of the One Health crisis. In 2016, we investigated 684 Japanese isolates of swine pathogenic E. coli belonging to four major serogroups and reported the emergence and increase in the highly multidrug-resistant serogroups O116 and OSB9 and the appearance of colistin-resistant strains. In the present study, by expanding our previous analysis, we determined the serotypes and antimicrobial resistance of 1,708 E. coli strains isolated from diseased swine between 1991 and 2019 in Japan and found recent increases in the prevalences of multidrug-resistant strains and minor serogroup strains. Among the antimicrobials examined in this study that have been approved for animal use, a third-generation cephalosporin was found to be effective against the most isolates (resistance rate: 1.2%) but not against highly multidrug-resistant strains. We also analyzed the susceptibilities of the 1,708 isolates to apramycin and bicozamycin, both which are available for treating swine in Japan, and found that the rates of resistance to apramycin and bicozamycin were low (6.7% and 5.8%, respectively), and both antimicrobials are more effective (resistance rates: 2.7% and 5.4%, respectively) than third-generation cephalosporins (resistance rate: 16.2%) against highly multidrug-resistant strains.

Keywords: apramycin; bicozamycin; multidrug-resistant; pathogenic Escherichia coli; swine.

Grants and funding

This study was conducted under the research project on “Regulatory Research Projects for Food Safety, Animal Health, and Plant Protection (JPJ008617.22682153)” funded by the Ministry of Agriculture, Forestry and Fisheries of Japan. This work was also supported in part by a Grants-in-Aid for Scientific Research (B), KAKENHI Grant Number: JP19H03133 to MK and TH, from the Japan Society for the Promotion of Science (JSPS).