{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,12]],"date-time":"2026-03-12T18:16:50Z","timestamp":1773339410406,"version":"3.50.1"},"reference-count":53,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T00:00:00Z","timestamp":1768176000000},"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. Cell. Infect. Microbiol."],"abstract":"\n Background<\/jats:title>\n \n Hypervirulent\n Klebsiella pneumoniae<\/jats:italic>\n (hv\n Kp<\/jats:italic>\n ) is a critical pathogen that causes highly lethal invasive infections with its virulence linked to that of aerobactin, the core siderophore system of hv\n Kp<\/jats:italic>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n Here, 20 porcine-derived\n K. pneumoniae<\/jats:italic>\n strains were subjected to capsular genotyping and the virulence of the strains was evaluated through mouse lethality assays. Whole-genome sequencing and analysis was performed on two K2 serotype strains (including highly and weakly virulent strains), and the differential virulence genes were analyzed. The virulence-related gene\n iucC<\/jats:italic>\n , identified in the hypervirulent K2 serotype strain KP10, was knocked out using homologous recombination to preliminarily explore its function in\n K. pneumoniae<\/jats:italic>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n In this study, a highly virulent K2-type strain KP10 and a low virulent K2-type strain KP6 were screened from 20 strains of porcine\n K. pneumoniae<\/jats:italic>\n . The results of the genome and virulence gene analyses revealed that compared with KP6, the highly virulent strain KP10 specifically encodes the\n iucC<\/jats:italic>\n gene. The \u25b3\n iucC<\/jats:italic>\n mutant of the high-virulence strain KP10 exhibited significantly reduced biofilm formation, decreased siderophore production, moderate serum sensitivity, and attenuated virulence. Furthermore, the mutant displayed decreased adhesion to IPEC-J2 cells, reduced cytotoxicity, and decreased cell mortality. These results revealed that\n iucC<\/jats:italic>\n is a major contributor to virulence in the KP10 hv\n Kp<\/jats:italic>\n strain. Notably,\n iucC<\/jats:italic>\n genes were detected in the genomes of\n K. pneumoniae<\/jats:italic>\n from humans and six different animal and environmental sources, and some\n iucC<\/jats:italic>\n genes were shared in\n K. pneumoniae<\/jats:italic>\n from these sources.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n \n Overall, this work provides a crucial theoretical foundation for elucidating\n iucC<\/jats:italic>\n function and the pathogenesis of\n K. pneumoniae.<\/jats:italic>\n Its widespread presence in different hosts and environments considerably increases the risk of cross species transmission and public health events.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fcimb.2025.1742219","type":"journal-article","created":{"date-parts":[[2026,1,12]],"date-time":"2026-01-12T08:12:05Z","timestamp":1768205525000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["The iucC gene is a major contributor to the virulence of hypervirulent Klebsiella pneumoniae"],"prefix":"10.3389","volume":"15","author":[{"given":"Chong","family":"Chen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li","family":"Wang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shuo","family":"Zu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hui","family":"Ning","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liran","family":"Song","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jianbao","family":"Dong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Changjiang","family":"Sun","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xin","family":"Feng","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenyu","family":"Han","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yalu","family":"Ji","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jingmin","family":"Gu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,1,12]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.diagmicrobio.2020.115139","article-title":"Molecular strain typing of multidrug-resistant Klebsiella pneumoniae: capsular wzi gene sequencing versus multiple locus variable number tandem repeat analysis","volume":"98","author":"Aboulela","year":"2020","journal-title":"Diagn. 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