{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T11:00:57Z","timestamp":1787742057435,"version":"build-2784847793"},"reference-count":27,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T00:00:00Z","timestamp":1769385600000},"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. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      The multidrug resistance of bovine-derived\n                      <jats:italic>Klebsiella pneumoniae<\/jats:italic>\n                      is a significant concern, with biofilm formation serving as a major factor in the escalation of antibiotic resistance. The function of cAMP receptor protein (CRP), which is encoded by the\n                      <jats:italic>crp<\/jats:italic>\n                      gene and acts as a central regulator of environmental sensing and virulence, remains unclear in pathogenic strains derived from livestock.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Purpose<\/jats:title>\n                    <jats:p>\n                      This study aims to investigate the influence of CRP overexpression on biofilm formation and antibiotic resistancein bovine-derived\n                      <jats:italic>Klebsiella pneumoniae<\/jats:italic>\n                      , with a particular focus on its effect against cotrimoxazole.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Recombinant strains with constitutive (P\n                      <jats:italic>kan<\/jats:italic>\n                      ) and inducible (P\n                      <jats:italic>tac<\/jats:italic>\n                      ) promoter-driven CRP overexpression were constructed using molecular cloning. Gene and protein expression were validated using RT-qPCR and immunoblotting analyses. Biofilm formation was quantified by crystal violet staining, antibiotic susceptibility to 23 agents was assessed using the Kirby-Bauer disk diffusion method, and metabolic burden was evaluated through growth curve analysis.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Result<\/jats:title>\n                    <jats:p>\n                      The CRP-overexpressing strain (KAN group) showed a 2.9-fold increase in CRP protein expression (\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.01) and a significant enhancement in biofilm formation (\n                      <jats:italic>p<\/jats:italic>\n                      \u202f&amp;lt;\u202f0.0001), without significant impact on bacterial growth. Notably, a reversal in antibiotic susceptibility was observed: while the wild-type strain was sensitive to cotrimoxazole (inhibition zone: 22\u202fmm), the CRP-overexpressing strain displayed complete resistance (inhibition zone: 7\u202fmm).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      Overexpression of CRP protein promotes biofilm formation and confers resistance to cotrimoxazole in bovine-derived\n                      <jats:italic>Klebsiella pneumonia<\/jats:italic>\n                      , indicating that CRP-mediated biofilm formation might be a key mechanism driving the observed cotrimoxazole resistance in this strain.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmicb.2026.1766955","type":"journal-article","created":{"date-parts":[[2026,1,26]],"date-time":"2026-01-26T07:19:23Z","timestamp":1769411963000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Overexpression of the crp gene promotes biofilm formation and increases antibiotic resistance in bovine-derived Klebsiella pneumoniae"],"prefix":"10.3389","volume":"17","author":[{"given":"Ying","family":"Zhang","sequence":"first","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiancheng","family":"Qi","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Gu","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sirun","family":"Yi","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yani","family":"Liu","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Keyue","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Linqi","family":"Guo","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhicai","family":"Zuo","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Sichuan Agricultural University","place":["Chengdu, Sichuan, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,1,26]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"685","DOI":"10.1111\/j.1462-2920.2007.01491.x","article-title":"The characterization of functions involved in the establishment and maturation of klebsiella pneumoniae in vitro biofilm reveals dual roles for surface exopolysaccharides","volume":"10","author":"Balestrino","year":"2008","journal-title":"Environ. 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