title: The role of flies in spreading the extended-spectrum β-lactamase gene from cattle.
abstract: The spreading of antimicrobial-resistant bacteria and genes from food-producing animals to humans has been a subject of increasing concern. To clarify the role of flies in spreading the extended-spectrum β-lactamase (ESBL) gene from food-producing animals to humans, we isolated and characterized a third-generation cephalosporin-resistant Escherichia coli strain from flies and cattle feces from a cattle barn. Cephalosporin-resistant strains were isolated from 14.3% (13/91) of houseflies, 10.3% (7/68) of false stable flies, and 7.5% (7/93) of cattle feces. Twenty-seven cephalosporin-resistant strains were tested for the presence of antimicrobial resistance genes. Of the 27 samples, 22 isolates from 11 houseflies, 5 false stable flies, and 6 cattle feces samples harbored the blaCTX-M-15 gene. All blaCTX-M-15-harboring isolates belonged to phylogenetic group D and the ST38 clonal group. Analysis of pulsed-field gel electrophoresis showed that these isolates were divided into two clusters, indicating that flies carried several of the same clones that were detected in cattle feces. All blaCTX-M-15 gene-harboring plasmids were transferable and were members of incompatibility group FIB. These results suggest that transferable plasmids encoding ESBL were prevalent among flies and cattle. As vectors, flies may play an important role in spreading ESBL-producing bacteria from food-producing animals to humans.
authors: Laboratory of Food Microbiology and Food Safety, Department of Health and Environmental Sciences, School of Veterinary Medicine, Rakuno Gakuen University , Ebetsu, Hokkaido, Japan .
authors: Masaru
authors: M
authors: Usui
authors: Tomohiro
authors: T
authors: Iwasa
authors: Akira
authors: A
authors: Fukuda
authors: Toyotaka
authors: T
authors: Sato
authors: Torahiko
authors: T
authors: Okubo
authors: Yutaka
authors: Y
authors: Tamura
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology* / Q000382:microbiology; D018550:Cephalosporin Resistance / Q000187:drug effects / Q000235:genetics; D002511:Cephalosporins / Q000494:pharmacology; D004175:Diptera / Q000382:microbiology*; D004197:Disease Reservoirs / Q000382:microbiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology; D022761:Gene Transfer, Horizontal; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D010957:Plasmids; D015995:Prevalence; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C473109:beta-lactamase CTX-M-15; D001618:beta-Lactamases