{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T13:16:33Z","timestamp":1777986993943,"version":"3.51.4"},"reference-count":49,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T00:00:00Z","timestamp":1776988800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases of the National Institutes of Health","doi-asserted-by":"publisher","award":["R01AI135118"],"award-info":[{"award-number":["R01AI135118"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000060","name":"National Institute of Allergy and Infectious Diseases of the National Institutes of Health","doi-asserted-by":"publisher","award":["1R01AI167989-01"],"award-info":[{"award-number":["1R01AI167989-01"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background\/Objectives: Integrons are genetic platforms that allow bacteria to acquire antimicrobial resistance (AMR) genes, making them a focal point for many AMR studies and surveillance programs. This study investigated how the prevalence of integrons (intI and attI genes) in third-generation cephalosporin-resistant E. coli (3GCR-Ec) varied across three different sources (i.e., healthy children, domestic animals and urinary tract infections). The study aimed to determine how different classes of AMR genes vary among 3GCR-Ec with integrons present versus those where integrons are absent. Methods: We analyzed 3GCR-Ec isolates collected from semirural parishes of Eastern Quito, Ecuador, that included: (1) 3GCR-Ec from healthy children (n = 946), (2) 3GCR-Ec from domestic animal species (n = 673), and 3GCR-Ec from patients with urinary tract infections (UTIs) (n = 138). Genomic analyses were performed for all 1757 sequences to determine how the presence and absence of integrons was associated with AMR gene carriage. Results: Among the total sequences of 3GCR-Ec evaluated across all datasets, nearly one-third (31%) were integron-negative. 3GCR-Ec from UTI patients, however, had a higher percentage containing integrons (79%). Across all sets of 3GCR-EC, integron-positive isolates carried an average of 10.3 (\u00b13.0 SD) AMR genes versus 4.8 (\u00b12.5 SD) AMR genes in integron-negative isolates. This study found that between 21% to 33% of 3GCR-Ec across the three different sources lacked integrons but maintained the ability to carry diverse classes of AMR genes, including beta-lactams, aminoglycosides, tetracyclines, and multidrug resistance mechanisms (e.g., general-purpose efflux pumps). Conclusions: While integrons were associated with greater AMR genes on average, the study highlights that solely relying on integrons for tracking drug-resistant bacteria misses a substantive portion of AMR that is present in integron-negative strains.<\/jats:p>","DOI":"10.3390\/antibiotics15050427","type":"journal-article","created":{"date-parts":[[2026,5,5]],"date-time":"2026-05-05T11:40:12Z","timestamp":1777981212000},"page":"427","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Antimicrobial Resistance Gene Profiles in Integron-Positive and Integron-Negative Third-Generation Cephalosporin-Resistant E. coli from Human and Animal Sources"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9635-1769","authenticated-orcid":false,"given":"Tin","family":"Ho","sequence":"first","affiliation":[{"name":"Environmental Health Sciences Division, University of California, 2121 Berkeley Way West, Berkeley, CA 94720, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6319-3012","authenticated-orcid":false,"given":"Liseth","family":"Salinas","sequence":"additional","affiliation":[{"name":"Instituto de Microbiolog\u00eda, Colegio de Ciencias Biol\u00f3gicas y Ambientales, Universidad San Francisco de Quito, Quito 170901, Ecuador"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2617-9021","authenticated-orcid":false,"given":"Gabriel","family":"Trueba","sequence":"additional","affiliation":[{"name":"Instituto de Microbiolog\u00eda, Colegio de Ciencias Biol\u00f3gicas y Ambientales, Universidad San Francisco de Quito, Quito 170901, Ecuador"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Heather K.","family":"Amato","sequence":"additional","affiliation":[{"name":"Department of Global, Environmental, and Occupational Health, School of Public Health, University of Maryland, 4200 Valley Drive, College Park, MD 20740, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nikolina","family":"Walas","sequence":"additional","affiliation":[{"name":"Environmental Health Sciences Division, University of California, 2121 Berkeley Way West, Berkeley, CA 94720, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mihir","family":"Pandya","sequence":"additional","affiliation":[{"name":"Environmental Health Sciences Division, University of California, 2121 Berkeley Way West, Berkeley, CA 94720, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Timothy","family":"Johnson","sequence":"additional","affiliation":[{"name":"Department of Veterinary and Biomedical Sciences, University of Minnesota, 1971 Commonwealth Avenue, Saint Paul, MN 55108, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7062-6293","authenticated-orcid":false,"given":"Jay","family":"Graham","sequence":"additional","affiliation":[{"name":"Environmental Health Sciences Division, University of California, 2121 Berkeley Way West, Berkeley, CA 94720, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1146\/annurev-genet-102209-163504","article-title":"Integrons","volume":"44","author":"Cambray","year":"2010","journal-title":"Annu. 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