{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T07:25:15Z","timestamp":1770967515384,"version":"3.50.1"},"reference-count":24,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T00:00:00Z","timestamp":1770940800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100017594","name":"Medical Science and Technology Project of Zhejiang Province","doi-asserted-by":"publisher","award":["2023\u5e741224\u5e74"],"award-info":[{"award-number":["2023\u5e741224\u5e74"]}],"id":[{"id":"10.13039\/501100017594","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100019976","name":"Science and Technology Bureau of Jiaxing City","doi-asserted-by":"publisher","award":["2024\u516c\u514310022\u5e74"],"award-info":[{"award-number":["2024\u516c\u514310022\u5e74"]}],"id":[{"id":"10.13039\/501100019976","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"\n Background<\/jats:title>\n \n Carbapenem-resistant\n Enterobacter<\/jats:italic>\n (CRE) has emerged as a critical clinical concern due to its broad multidrug resistance. This study aims to characterize the features of clinical CRE strains co-harboring the\n bla<\/jats:italic>\n NDM-1<\/jats:sub>\n and\n mcr-9<\/jats:italic>\n genes from three burn patients.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n This study collected 110 non-repetitive carbapenem-resistant\n Enterobacteriaceae<\/jats:italic>\n (CRE) from clinical settings.\n bla<\/jats:italic>\n NDM-1<\/jats:sub>\n and\n mcr-9<\/jats:italic>\n genes were identified by PCR, and strains were identified via MALDI-TOF MS and 16S rRNA sequencing. Minimum inhibitory concentrations (MICs) of common antimicrobial agents were determined by the broth microdilution method. The conjugation experiment was used to verify the transfer of resistance plasmids. Whole-genome sequencing (WGS) was performed using NovaSeq and PacBio_HIFI platforms, and analyzed through bioinformatics to characterize the resistance genes, virulence factors, plasmid profiles, and genetic relatedness of the bacterial strains.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Three carbapenem-resistant\n Enterobacter hormaechei<\/jats:italic>\n (CR-\n E. hormaechei<\/jats:italic>\n ) strains co-harboring\n bla<\/jats:italic>\n NDM-1<\/jats:sub>\n and\n mcr-9<\/jats:italic>\n were isolated from burn patients, and exhibited broad multidrug resistance with 100% conjugation efficiency. Whole-genome sequencing (WGS) showed that CR-1025 and CR-1050 carried 12 additional resistance genes (targeting aminoglycosides, \u03b2-lactams, etc.), while CR-1051 harbored 9. The\n mcr-9<\/jats:italic>\n gene was localized on IncHI2-type plasmids, and the\n bla<\/jats:italic>\n NDM-1<\/jats:sub>\n gene was localized on IncX3-type plasmids in CR-1025 and CR-1050 and on an IncHI2-type plasmid in CR-1051. Multilocus sequence typing confirmed all strains as sequence type 97 (ST97), and Venn diagram analysis showed close genetic relatedness among the strains.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n \n In conclusion, CR-\n E. hormaechei<\/jats:italic>\n co-harboring\n bla<\/jats:italic>\n NDM-1<\/jats:sub>\n and\n mcr-9<\/jats:italic>\n exhibits genetic diversity and plasmid mobility, posing a risk of cross-species transmission and clonal spread mediated by mobile genetic elements. Urgent measures are required to curb the dissemination of such multidrug-resistant strains in clinical settings.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fcimb.2026.1742596","type":"journal-article","created":{"date-parts":[[2026,2,13]],"date-time":"2026-02-13T06:39:57Z","timestamp":1770964797000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Co-occurrence of mcr-9 and blaNDM-1 in carbapenem-resistant Enterobacter hormaechei from burn patients"],"prefix":"10.3389","volume":"16","author":[{"given":"Xingchen","family":"Tao","sequence":"first","affiliation":[{"name":"Department of Laboratory, Jiaxing Maternal and Child Health Care Hospital (Affiliated Women\u2019s and Children\u2019s Hospital of Jiaxing University)","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lingyi","family":"Zeng","sequence":"additional","affiliation":[{"name":"Microbiology Laboratory, Hangzhou Center for Disease Control and Prevention (Hangzhou Health Supervision Institution)","place":["Hangzhou, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xinyi","family":"Sun","sequence":"additional","affiliation":[{"name":"Department of Laboratory, Jiaxing Maternal and Child Health Care Hospital (Affiliated Women\u2019s and Children\u2019s Hospital of Jiaxing University)","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuhai","family":"Du","sequence":"additional","affiliation":[{"name":"Department of Laboratory, Jiaxing Maternal and Child Health Care Hospital (Affiliated Women\u2019s and Children\u2019s Hospital of Jiaxing University)","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liping","family":"Zhong","sequence":"additional","affiliation":[{"name":"Department of Laboratory, Jiaxing Maternal and Child Health Care Hospital (Affiliated Women\u2019s and Children\u2019s Hospital of Jiaxing University)","place":["Jiaxing, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,2,13]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1016\/j.scitotenv.2023.162649","article-title":"First reported detection of the mobile colistin resistance genes, mcr-8 and mcr-9, in the Irish environment","volume":"876","author":"Cahill","year":"2023","journal-title":"Sci. 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