{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T08:57:59Z","timestamp":1790845079683,"version":"4.1.0"},"reference-count":32,"publisher":"Wiley","license":[{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:00:00Z","timestamp":1790812800000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["24K10230"],"award-info":[{"award-number":["24K10230"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001691","name":"Japan Society for the Promotion of Science","doi-asserted-by":"publisher","award":["25K11767"],"award-info":[{"award-number":["25K11767"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100007449","name":"Takeda Science Foundation","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100007449","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Microbiology and Immunology"],"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    As companion animals live in close contact with humans, the presence of antimicrobial\u2010resistant organisms in these animals is an important issue in veterinary medicine from a One Health perspective. In this study, we isolated a total of 385\n                    <jats:italic>Escherichia coli<\/jats:italic>\n                    strains from fecal samples collected from 218 companion dogs and 167 companion cats that visited veterinary clinics in Tokyo, Japan, from 2021 to 2024. Antimicrobial resistance to third\u2010generation cephalosporins and fluoroquinolones increased significantly with host age, even though fecal abnormalities were low relevance. A total of 60 isolates were resistant to at least one third\u2010generation cephalosporin, and whole\u2010genome analysis was performed to further characterize these isolates. The isolates were classified as CTX\u2010M gene\u2010carrying or AmpC\u2010associated isolates, including those carrying acquired AmpC genes and those harboring chromosomal\n                    <jats:italic>ampC<\/jats:italic>\n                    promoter mutations. The age\u2010associated increase was more pronounced among CTX\u2010M gene\u2010carrying isolates than among AmpC\u2010associated isolates. CTX\u2010M gene\u2010carrying isolates frequently exhibited concurrent levofloxacin resistance and were predominantly represented by ST131. Core\u2010genome multilocus sequence typing revealed that these CTX\u2010M gene\u2010carrying isolates were phylogenetically similar to previously reported isolates of both human and animal origin. These findings suggest that the age\u2010associated increase in resistance is related to the expansion of specific CTX\u2010M gene\u2010carrying lineages rather than to a uniform increase across all cephalosporin\u2010resistance mechanisms. Our results support the need for continuous investigation within a One Health framework and further epidemiological and genomic surveillance.\n                  <\/jats:p>","DOI":"10.1111\/1348-0421.70095","type":"journal-article","created":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T08:12:40Z","timestamp":1790842360000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Age\u2010Associated Antimicrobial Resistance in\n                    <i>Escherichia coli<\/i>\n                    Isolates From Companion Dogs and Cats Linked to CTX\u2010M Gene Carriage"],"prefix":"10.1111","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4524-284X","authenticated-orcid":false,"given":"Kai","family":"Kobayashi","sequence":"first","affiliation":[{"name":"Department of Microbiology Tokyo Metropolitan Institute of Public Health Tokyo Japan"},{"name":"Laboratory of Veterinary Public Health, School of Veterinary Medicine, Faculty of Veterinary Science Nippon Veterinary and Life Science University Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6339-8568","authenticated-orcid":false,"given":"Hiroaki","family":"Kubota","sequence":"additional","affiliation":[{"name":"Department of Microbiology Tokyo Metropolitan Institute of Public Health Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9294-5065","authenticated-orcid":false,"given":"Tsukasa","family":"Ariyoshi","sequence":"additional","affiliation":[{"name":"Department of Microbiology Tokyo Metropolitan Institute of Public Health Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0521-4940","authenticated-orcid":false,"given":"Kohji","family":"Mori","sequence":"additional","affiliation":[{"name":"Department of Microbiology Tokyo Metropolitan Institute of Public Health Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4520-2031","authenticated-orcid":false,"given":"Yoshitsugu","family":"Ochiai","sequence":"additional","affiliation":[{"name":"Laboratory of Veterinary Public Health, School of Veterinary Medicine, Faculty of Veterinary Science Nippon Veterinary and Life Science University Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0541-706X","authenticated-orcid":false,"given":"Kenji","family":"Sadamasu","sequence":"additional","affiliation":[{"name":"Department of Microbiology Tokyo Metropolitan Institute of Public Health Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Takashi","family":"Chiba","sequence":"additional","affiliation":[{"name":"Department of Microbiology Tokyo Metropolitan Institute of Public Health Tokyo Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,10,1]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1128\/microbiolspec.ARBA-0026-2017"},{"key":"e_1_2_11_3_1","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.00135-18"},{"key":"e_1_2_11_4_1","doi-asserted-by":"publisher","DOI":"10.3389\/fvets.2022.916461"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vetmic.2024.110220"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.vetmic.2010.04.025"},{"key":"e_1_2_11_7_1","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0246482"},{"key":"e_1_2_11_8_1","doi-asserted-by":"publisher","DOI":"10.1128\/msystems.01236-22"},{"key":"e_1_2_11_9_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.meegid.2018.09.009"},{"key":"e_1_2_11_10_1","doi-asserted-by":"publisher","DOI":"10.1007\/s00284-026-04792-7"},{"key":"e_1_2_11_11_1","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.01596-17"},{"key":"e_1_2_11_12_1","doi-asserted-by":"publisher","DOI":"10.3201\/eid2211.160519"},{"key":"e_1_2_11_13_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.onehlt.2021.100236"},{"key":"e_1_2_11_14_1","unstructured":"Clinical and Laboratory Standards Institute Performance Standards for Antimicrobial Susceptibility Testing. CLSI Supplement M100. 35th ed. Wayne (PA): CLSI;2025."},{"key":"e_1_2_11_15_1","doi-asserted-by":"publisher","DOI":"10.1093\/nar\/gkae902"},{"key":"e_1_2_11_16_1","doi-asserted-by":"publisher","DOI":"10.1002\/cpbi.102"},{"key":"e_1_2_11_17_1","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-019-10210-3"},{"key":"e_1_2_11_18_1","doi-asserted-by":"publisher","DOI":"10.1093\/bioinformatics\/btx713"},{"key":"e_1_2_11_19_1","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkaa345"},{"key":"e_1_2_11_20_1","doi-asserted-by":"publisher","DOI":"10.1101\/gr.232397.117"},{"key":"e_1_2_11_21_1","doi-asserted-by":"publisher","DOI":"10.1177\/1098612X21993657"},{"key":"e_1_2_11_22_1","doi-asserted-by":"publisher","DOI":"10.5326\/JAAHA-MS-6999"},{"key":"e_1_2_11_23_1","doi-asserted-by":"publisher","DOI":"10.1038\/bmt.2012.244"},{"key":"e_1_2_11_24_1","doi-asserted-by":"publisher","DOI":"10.3389\/fvets.2020.622495"},{"key":"e_1_2_11_25_1","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkz462"},{"key":"e_1_2_11_26_1","doi-asserted-by":"publisher","DOI":"10.3390\/ani15101357"},{"key":"e_1_2_11_27_1","doi-asserted-by":"publisher","DOI":"10.1093\/jacamr\/dlaf008"},{"key":"e_1_2_11_28_1","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiab638"},{"key":"e_1_2_11_29_1","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiy031"},{"key":"e_1_2_11_30_1","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2022.838392"},{"key":"e_1_2_11_31_1","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.02929-15"},{"key":"e_1_2_11_32_1","doi-asserted-by":"publisher","DOI":"10.3390\/antibiotics10121463"},{"key":"e_1_2_11_33_1","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.01613-20"}],"container-title":["Microbiology and Immunology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/1348-0421.70095","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/full-xml\/10.1111\/1348-0421.70095","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1111\/1348-0421.70095","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T08:12:43Z","timestamp":1790842363000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1111\/1348-0421.70095"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,1]]},"references-count":32,"alternative-id":["10.1111\/1348-0421.70095"],"URL":"https:\/\/doi.org\/10.1111\/1348-0421.70095","archive":["Portico"],"relation":{},"ISSN":["0385-5600","1348-0421"],"issn-type":[{"value":"0385-5600","type":"print"},{"value":"1348-0421","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,1]]},"assertion":[{"value":"2026-05-11","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-09-16","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2026-10-01","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"1348-0421.70095"}}