Authorship：Lead author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Journal of Global Antimicrobial Resistance  

Objectives: The production of expanded-spectrum beta-lactamases (ESBLs) and fluoroquinolone resistance in Enterobacteriaceae has become a global concern. The aim of this study was to investigate the spread of ESBL-producing and fluoroquinolone-resistant avian pathogenic Escherichia coli (APEC) in Kagoshima, a prefecture with the largest amount of poultry in Japan. Methods: The antimicrobial susceptibility and genetic characteristics of 228 APEC strains isolated from 57 farms in Kagoshima Prefecture, Japan, between 2005 and 2017 were analysed. Information about the companies with hatcheries connected to the farms was also collected, and the epidemiologic relatedness of APEC strains and the processes of adopting chicks were compared. Results: Seven CTX-M-type ESBL genes, bla<inf>CTX-M-1</inf>, bla<inf>CTX-M-2</inf>, bla<inf>CTX-M-14</inf>, bla<inf>CTX-M-15</inf>, bla<inf>CTX-M-25</inf>, bla<inf>CTX-M-55</inf>, and bla<inf>CTX-M-65</inf>, were found in 60 (26.3%) of the 228 APEC strains. The ciprofloxacin-resistant strains belonged to 10 different sequence types (ST10, ST23, ST93, ST155, ST156, ST350, ST359, ST602, ST648, and ST9479), and the two ST602 strains showed remarkably high ciprofloxacin resistance (MIC: 128 µg/mL) and had amino acid mutations in GyrA (S83L and D87N), ParC (S80I), and ParE (E460A). A CTX-M-55-type ESBL-producing fluoroquinolone-resistant Og78-ST23 strain was isolated multiple times over two years on a farm. Furthermore, epidemiologically closely related strains were isolated from different farms that used the same common hatcheries. Conclusions: APEC is often transferred from hatcheries to farms via healthy chicks, and the prudent use of antimicrobials and careful monitoring of resistant strains on poultry farms and hatcheries are important in preventing the selection and spread of high-risk APEC strains such as CTX-M-55-type ESBL-producing Og78-ST23.

DOI： 10.1016/j.jgar.2023.10.015

Scopus

Authorship：Lead author   Language：English   Publishing type：Research paper (scientific journal)  

Pathogenic Escherichia coli is an important cause of diarrhea, edema disease, and septicemia in swine. In Japan, the volume of antimicrobial drugs used for animals is highest in swine, but information about the prevalence of antimicrobial-resistant bacteria is confined to apparently healthy animals. In the present study, we determined the O serogroups, virulence factors, and antimicrobial resistance of 360 E. coli isolates from swine that died of disease in Kagoshima Prefecture, Japan, between 1999 and 2017. The isolates of the predominant serogroups O139, OSB9, O149, O8, and O116 possessed virulence factor genes typically found in diarrheagenic E. coli. We further found five strains of third-generation cephalosporin-resistant E. coli that each produced an extended-spectrum β-lactamase encoded by blaCTX-M-14, blaCTX-M-15, blaCTX-M-24, blaCTX-M-61, or blaSHV-12. In 218 swine with a clear history of antimicrobial drug use, we further analyzed associations between the use of antimicrobials for the treatment of diseased swine and the isolation of resistant E. coli. We found significant associations between antimicrobial use and selection of resistance to the same class of antimicrobials, such as the use of ceftiofur and resistance to cefotaxime, cefazolin, or ampicillin, the use of aminoglycosides and resistance to streptomycin, and the use of phenicols and resistance to chloramphenicol. A significant association between antimicrobial use and the resistance of E. coli isolates to structurally unrelated antimicrobials, such as the use of ceftiofur and resistance to chloramphenicol, was also observed.

DOI： 10.1292/jvms.20-0338

PubMed

Language：English  

DOI： 10.12935/jvma.73.449

Authorship：Lead author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)  

DOI： 10.12935/jvma.72.686

Presentation type：Poster presentation  

Presentation type：Oral presentation (general)  

Presentation type：Oral presentation (general)  

Presentation type：Public lecture, seminar, tutorial, course, or other speech  

Award type：Award from Japanese society, conference, symposium, etc. 

Award type：Award from Japanese society, conference, symposium, etc.