{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T04:58:25Z","timestamp":1760245105587,"version":"build-2065373602"},"reference-count":43,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T00:00:00Z","timestamp":1760054400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Shanghai Agriculture Applied Technology Development Program, China","award":["2023-02-08-00-12-F04584"],"award-info":[{"award-number":["2023-02-08-00-12-F04584"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"crossref","award":["32273056"],"award-info":[{"award-number":["32273056"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Xinjiang Uygur Autonomous Region \u201cTianshan Talents\u201d Cultivation Program\u2014\u201cThree Rural\u201d Key Talent Development Project","award":["2023SNGGGCC008"],"award-info":[{"award-number":["2023SNGGGCC008"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background\/Objectives: The global dissemination of tet(X) variants critically threatens tigecycline efficacy as a last-resort antibiotic. The aim of this study was to characterize a tet(X6)-carrying integrative and conjugative element (ICE) in a multidrug-resistant Chryseobacterium lecithinasegens strain, SHZ29, isolated from Shanghai, China. Methods: Minimum inhibitory concentrations (MICs) were determined by broth microdilution for SHZ29. Whole genomic sequencing and bioinformatic analysis were performed to depict the structure of the novel tet(X6)-carrying ICE. Inverse PCR and conjugation experiments were conducted to investigate the transfer ability of the ICE. Results: We depicted a novel tet(X6)-carrying ICE, named ICECleSHZ29, which is 74,906 bp in size and inserted into the 3\u2032 end of tRNA-Met-CAT gene of the C. lecithinasegens strain SHZ29, with 17 bp direct repeats (5\u2032-tcccgtcttcgctacaa-3\u2032). This ICE possesses a 38 kb conserved backbone and four variable regions (VR1-4), with VR3 aggregating multiple resistance genes, including tet(X6), tet(X2), erm(F), ere(D), floR, catB, sul2, ant(6)-I and blaOXA-1327. NCBI database searching identified 13 additional ICEs sharing a similar backbone to ICECleSHZ29. These ICECleSHZ29-like ICEs could be classified into two types based on their distinct insertion sites: Type I, inserted at the tRNA-Met-CAT gene; and Type II, inserted at the tRNA-Glu-TTC gene. Phylogenetic analysis indicated that differences in integrases may result in differences in the insertion site among these ICEs. A circular intermediate form of ICECleSHZ29 was detected by inverse PCR. However, the conjugation experiments using Escherichia coli EC600 as recipients failed. Conclusions: To our knowledge, this study provides the first report of tet(X6) in C. lecithinasegens and characterizes its carrier, a novel ICE: ICECleSHZ29.<\/jats:p>","DOI":"10.3390\/antibiotics14101002","type":"journal-article","created":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T09:45:01Z","timestamp":1760089501000},"page":"1002","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["ICECleSHZ29: Novel Integrative and Conjugative Element (ICE)-Carrying Tigecycline Resistance Gene tet(X6) in Chryseobacterium lecithinasegens"],"prefix":"10.3390","volume":"14","author":[{"given":"Xi","family":"Chen","sequence":"first","affiliation":[{"name":"College of Veterinary Medicine, Xinjiang Agricultural University, Urmuqi 830052, China"},{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yifei","family":"Zhang","sequence":"additional","affiliation":[{"name":"Shanghai Animal Disease Control Center, Shanghai 201103, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chunling","family":"Jiang","sequence":"additional","affiliation":[{"name":"Shanghai Center of Agri-Products Quality and Safety, Shanghai 201708, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yafang","family":"Lin","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaohui","family":"Yao","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Xinjiang Agricultural University, Urmuqi 830052, China"},{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-8458-9290","authenticated-orcid":false,"given":"Wansen","family":"Nie","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Xinjiang Agricultural University, Urmuqi 830052, China"},{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lin","family":"Li","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3246-6273","authenticated-orcid":false,"given":"Jianchao","family":"Wei","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Donghua","family":"Shao","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ke","family":"Liu","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2967-8686","authenticated-orcid":false,"given":"Zongjie","family":"Li","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4211-0817","authenticated-orcid":false,"given":"Yafeng","family":"Qiu","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhiyong","family":"Ma","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4134-4024","authenticated-orcid":false,"given":"Beibei","family":"Li","sequence":"additional","affiliation":[{"name":"Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lining","family":"Xia","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Xinjiang Agricultural University, Urmuqi 830052, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.envint.2016.03.023","article-title":"Discharge of swine wastes risks water quality and food safety: Antibiotics and antibiotic resistance genes from swine sources to the receiving environments","volume":"92\u201393","author":"He","year":"2016","journal-title":"Environ. 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