{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T09:07:16Z","timestamp":1789031236391,"version":"build-2803163510"},"reference-count":51,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T00:00:00Z","timestamp":1788998400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"\n Background<\/jats:title>\n \n Canine otitis externa provides a chronic, inflamed and frequently antimicrobial-exposed niche in which\n Pseudomonas aeruginosa<\/jats:italic>\n can persist through a coordinated repertoire of adhesion, biofilm, iron-acquisition, secretion and toxin systems.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n We characterized the virulence-associated genomic architecture of a historical Hungarian collection obtained from canine otitis cases in 2010 and 2017. Of the 70 isolate identifiers in the nominal range 70\u2013139, 60 had corresponding long-read assemblies and linked VFDB screening records. One assembly was excluded after genome-based taxonomic validation showed that it did not meet the species-level criterion for\n P. aeruginosa<\/jats:italic>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Primary absence-sensitive analyses were restricted to 52 genome-confirmed\n P. aeruginosa<\/jats:italic>\n assemblies meeting prespecified CheckM criteria (completeness \u226595%, contamination \u22645%), while seven additional genome-confirmed\n P. aeruginosa<\/jats:italic>\n assemblies that did not meet the primary CheckM criteria were retained only for descriptive contextualization and were excluded from prevalence denominators and absence-sensitive analyses. The primary cohort contained 242 distinct virulence-associated genes, with a median of 230.5 genes per isolate. Of these, 217 (89.7%) were core-like, occurring in at least 95% of genomes. Alginate, type IV pilus, flagellar, siderophore, phenazine, quorum-sensing, type II, type III and type VI secretion backbones were broadly conserved. In contrast, type III effector content was heterogeneous:\n exoT<\/jats:italic>\n occurred in 52\/52 isolates,\n exoY<\/jats:italic>\n in 50\/52,\n exoS<\/jats:italic>\n in 49\/52 and\n exoU<\/jats:italic>\n in 4\/52; one isolate showed assembly-level co-detection of\n exoS<\/jats:italic>\n and an\n exoU<\/jats:italic>\n -homologous sequence. Whole-virulome composition did not differ detectably between 2010 and 2017 (square-root Jaccard PERMANOVA, R\n 2<\/jats:sup>\n \u202f=\u202f0.0134,\n p<\/jats:italic>\n \u202f=\u202f0.6083), and no individual gene remained associated with collection year after false-discovery-rate correction.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n These data define a conserved historical virulence-associated genomic backbone punctuated by isolate-level effector and surface-structure variation. The detected genes are interpreted as genomic homologues and repertoire features rather than as evidence of their expression or functional contribution to pathogenicity.<\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fvets.2026.1951261","type":"journal-article","created":{"date-parts":[[2026,9,10]],"date-time":"2026-09-10T08:15:50Z","timestamp":1789028150000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["A conserved virulence backbone and heterogeneous type III secretion effector profiles in historical canine otitis-associated Pseudomonas aeruginosa from Hungary"],"prefix":"10.3389","volume":"13","author":[{"given":"Merc\u00e9desz Adrienn","family":"Veres","sequence":"first","affiliation":[{"name":"Department of Pharmacology and Toxicology, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bal\u00e1zs","family":"Moravcsik","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Toxicology, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrik","family":"Mag","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Toxicology, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eszter","family":"Kaszab","sequence":"additional","affiliation":[{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"Department of Bioinformatics, One Health Institute, Faculty of Health Sciences, University of Debrecen","place":["Debrecen, Hungary"]},{"name":"Department of Microbiology and Infectious Diseases, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Enik\u0151","family":"Feh\u00e9r","sequence":"additional","affiliation":[{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"Department of Microbiology and Infectious Diseases, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"National Laboratory of Virology, Szent\u00e1gothai Research Centre, University of P\u00e9cs","place":["P\u00e9cs, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c1kos","family":"Jerzsele","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Toxicology, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00c1d\u00e1m","family":"Kerek","sequence":"additional","affiliation":[{"name":"Department of Pharmacology and Toxicology, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]},{"name":"National Laboratory of Infectious Animal Diseases, Antimicrobial Resistance, Veterinary Public Health and Food Chain Safety, University of Veterinary Medicine Budapest","place":["Budapest, Hungary"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,10]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"7","DOI":"10.1186\/s40575-021-00106-1","article-title":"Frequency and predisposing factors for canine otitis externa in the UK-a primary veterinary care epidemiological view","volume":"8","author":"O\u2019Neill","year":"2021","journal-title":"Canine Med Genet"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"2650","DOI":"10.3390\/microorganisms11112650","article-title":"Pseudomonas spp. in canine otitis externa","volume":"11","author":"Secker","year":"2023","journal-title":"Microorganisms"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"742","DOI":"10.3390\/ani14050742","article-title":"Microbiological survey and evaluation of antimicrobial susceptibility patterns of microorganisms obtained from suspect cases of canine otitis externa in gran Canaria, 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