{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T11:58:18Z","timestamp":1787313498171,"version":"build-2736575974"},"reference-count":30,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2025,3,24]],"date-time":"2025-03-24T00:00:00Z","timestamp":1742774400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program","award":["2019BT02N054"],"award-info":[{"award-number":["2019BT02N054"]}]},{"name":"Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program","award":["2022 YFC2303900"],"award-info":[{"award-number":["2022 YFC2303900"]}]},{"name":"Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program","award":["202201010300"],"award-info":[{"award-number":["202201010300"]}]},{"name":"Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program","award":["2021KQNCX006"],"award-info":[{"award-number":["2021KQNCX006"]}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2019BT02N054"],"award-info":[{"award-number":["2019BT02N054"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2022 YFC2303900"],"award-info":[{"award-number":["2022 YFC2303900"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["202201010300"],"award-info":[{"award-number":["202201010300"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2021KQNCX006"],"award-info":[{"award-number":["2021KQNCX006"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Science and Technology Program of Guangzhou, China","award":["2019BT02N054"],"award-info":[{"award-number":["2019BT02N054"]}]},{"name":"Science and Technology Program of Guangzhou, China","award":["2022 YFC2303900"],"award-info":[{"award-number":["2022 YFC2303900"]}]},{"name":"Science and Technology Program of Guangzhou, China","award":["202201010300"],"award-info":[{"award-number":["202201010300"]}]},{"name":"Science and Technology Program of Guangzhou, China","award":["2021KQNCX006"],"award-info":[{"award-number":["2021KQNCX006"]}]},{"name":"Project of Educational Commission of Guangdong Province of China","award":["2019BT02N054"],"award-info":[{"award-number":["2019BT02N054"]}]},{"name":"Project of Educational Commission of Guangdong Province of China","award":["2022 YFC2303900"],"award-info":[{"award-number":["2022 YFC2303900"]}]},{"name":"Project of Educational Commission of Guangdong Province of China","award":["202201010300"],"award-info":[{"award-number":["202201010300"]}]},{"name":"Project of Educational Commission of Guangdong Province of China","award":["2021KQNCX006"],"award-info":[{"award-number":["2021KQNCX006"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>Background: The emergence of linezolid resistance, mediated by genes such as optrA and cfr(D), poses a growing public health threat. While these genes have been detected in clinical and animal-derived Enterococcus species, their presence in underexplored species like Enterococcus saccharolyticus remains undocumented, leaving a significant gap in our understanding of their dissemination and stability. Method: E. saccharolyticus GXN23C125Es was screened for the presence of known linezolid resistance genes via PCR analysis. Conjugation and stability experiments were used to evaluate the transferability and stability of the resistance genes. The complete genome of GXN23C125Es was obtained using both the Illumina and Nanopore platforms. Results: We report the first identification of optrA and cfr(D) in GXN23C125Es from chicken feces in China. Whole-genome sequencing revealed multiple plasmid-borne resistance genes, including optrA, cfr(D), fexA, and erm(A). Stability testing demonstrated that optrA was highly stable, while cfr(D) was rapidly lost without selective pressure. Conclusions: These findings highlight E. saccharolyticus as a potential reservoir for linezolid resistance genes, underscoring the need for enhanced surveillance of resistance determinants in animal-associated bacteria. Understanding the dissemination dynamics of optrA and cfr(D) is crucial for mitigating their impact on public health and guiding antimicrobial resistance management strategies.<\/jats:p>","DOI":"10.3390\/antibiotics14040337","type":"journal-article","created":{"date-parts":[[2025,3,24]],"date-time":"2025-03-24T12:01:50Z","timestamp":1742817710000},"page":"337","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Emergence of Linezolid Resistance Genes optrA and cfr(D) in an Enterococcus\u00a0saccharolyticus from Chicken"],"prefix":"10.3390","volume":"14","author":[{"given":"Xun","family":"Gao","sequence":"first","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiao","family":"Luo","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruorou","family":"Qian","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guolong","family":"Gao","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jinghao","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Junhao","family":"Hong","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Yue","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3930-7857","authenticated-orcid":false,"given":"Jian-Hua","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi-Yun","family":"Liu","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China"},{"name":"Key Laboratory of Zoonosis of Ministry of Agricultural and Rural Affairs, Guangzhou 510642, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.plasmid.2018.09.011","article-title":"Linezolid resistance genes and genetic elements enhancing their dissemination in enterococci and streptococci","volume":"99","author":"Sadowy","year":"2018","journal-title":"Plasmid"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Schwarz, S., Zhang, W., Du, X.D., Kr\u00fcger, H., Fe\u00dfler, A.T., Ma, S., Zhu, Y., Wu, C., Shen, J., and Wang, Y. (2021). Mobile oxazolidinone resistance genes in Gram-positive and Gram-negative bacteria. Clin. Microbiol. Rev., 34.","DOI":"10.1128\/CMR.00188-20"},{"key":"ref_3","first-page":"2200496","article-title":"High occurrence of Enterococcus faecalis, Enterococcus faecium, and Vagococcus lutrae harbouring oxazolidinone resistance genes in raw meat-based diets for companion animals\u2014A public health issue, Switzerland, September 2018 to May 2020","volume":"28","author":"Heyvaert","year":"2023","journal-title":"Euro Surveill."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2596","DOI":"10.1093\/jac\/dkac263","article-title":"Oxazolidinones: Mechanisms of resistance and mobile genetic elements involved","volume":"77","author":"Brenciani","year":"2022","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"598","DOI":"10.1093\/jac\/dkab456","article-title":"Occurrence of a plasmid co-carrying cfr(D) and poxtA2 linezolid resistance genes in Enterococcus faecalis and Enterococcus casseliflavus from porcine manure, Italy","volume":"77","author":"Cinthi","year":"2022","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2329","DOI":"10.1093\/jac\/dkq331","article-title":"Assessment of linezolid resistance mechanisms among Staphylococcus epidermidis causing bacteraemia in Rome, Italy","volume":"65","author":"Mendes","year":"2010","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2182","DOI":"10.1093\/jac\/dkv116","article-title":"A novel gene, optrA, that confers transferable resistance to oxazolidinones and phenicols and its presence in Enterococcus faecalis and Enterococcus faecium of human and animal origin","volume":"70","author":"Wang","year":"2015","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1763","DOI":"10.1093\/jac\/dky088","article-title":"Characterization of poxtA, a novel phenicol-oxazolidinone-tetracycline resistance gene from an MRSA of clinical origin","volume":"73","author":"Antonelli","year":"2018","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Driesen, M., Timmermans, M., Cargnel, M., Simons, X., Filippitzi, M.E., Catry, B., Dal Pozzo, F., Vanderhaeghen, W., Callens, B., and Dispas, M. (2024). Risk factor analysis for occurrence of linezolid-resistant bacteria in the digestive and respiratory tract of food-producing Animals in Belgium: A Pilot Study. Antibiotics, 13.","DOI":"10.3390\/antibiotics13080707"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Gi\u00e3o, J., Le\u00e3o, C., Albuquerque, T., Clemente, L., and Amaro, A. (2022). Antimicrobial Susceptibility of Enterococcus Isolates from Cattle and Pigs in Portugal: Linezolid Resistance Genes optrA and poxtA. Antibiotics, 11.","DOI":"10.3390\/antibiotics11050615"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"168683","DOI":"10.1016\/j.scitotenv.2023.168683","article-title":"Molecular epidemiology, phenotypic and genomic characterization of antibiotic-resistant enterococcal isolates from diverse farm animals in Xinjiang, China","volume":"912","author":"Chen","year":"2024","journal-title":"Sci. Total Environ."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"N\u00fcesch-Inderbinen, M., Biggel, M., Haussmann, A., Treier, A., Heyvaert, L., Cernela, N., and Stephan, R. (2023). Oxazolidinone resistance genes in florfenicol-resistant enterococci from beef cattle and veal calves at slaughter. Front. Microbiol., 14.","DOI":"10.3389\/fmicb.2023.1150070"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1469","DOI":"10.1093\/jac\/dkz097","article-title":"Emergence of optrA-mediated linezolid resistance in enterococci from France, 2006\u201316","volume":"74","author":"Sassi","year":"2019","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"105831","DOI":"10.1016\/j.ijantimicag.2019.10.012","article-title":"Linezolid-resistant ST872 Enteroccocus faecium harbouring optrA and cfr(D) oxazolidinone resistance genes","volume":"55","author":"Pang","year":"2020","journal-title":"Int. J. Antimicrob. Agents"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1637","DOI":"10.1093\/jac\/dkad142","article-title":"Co-occurrence of multiple plasmid-borne linezolid resistance genes-optrA, cfr, poxtA2 and cfr(D) in an Enterococcus faecalis isolate from retail meat","volume":"78","author":"Shen","year":"2023","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Bamigbade, G.B., Subhash, A.J., Al-Ramadi, B., Kamal-Eldin, A., Gan, R.Y., Liu, S.Q., and Ayyash, M. (2024). Gut microbiota modulation, prebiotic and bioactive characteristics of date pomace polysaccharides extracted by microwave-assisted deep eutectic solvent. Int. J. Biol. Macromol., 262.","DOI":"10.1016\/j.ijbiomac.2024.130167"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Kurban, D., Roy, J.P., Kabera, F., Fr\u00e9chette, A., Um, M.M., Albaaj, A., Rowe, S., Godden, S., Adkins, P.R.F., and Middleton, J.R. (2022). Diagnosing Intra-mammary Infection: Meta-analysis and mapping review on frequency and udder health relevance of microorganism species isolated from Bovine milk samples. Animals, 12.","DOI":"10.3390\/ani12233288"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Wang, Z., Liu, D., Zhang, J., Liu, L., Zhang, Z., Liu, C., Hu, S., Wu, L., He, Z., and Sun, H. (2024). Genomic epidemiology reveals multiple mechanisms of linezolid resistance in clinical enterococci in China. Ann. Clin. Microbiol. Antimicrob., 23.","DOI":"10.1186\/s12941-024-00689-0"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1016\/j.vetmic.2014.02.037","article-title":"First report of multiresistance gene cfr in Enterococcus species casseliflavus and gallinarum of swine origin","volume":"170","author":"Liu","year":"2014","journal-title":"Vet. Microbiol."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Tang, B., Zou, C., Schwarz, S., Xu, C., Hao, W., Yan, X.M., Huang, Y., Ni, J., Yang, H., and Du, X.D. (2023). Linezolid-resistant Enterococcus faecalis of chicken origin harbored chromosome-borne optrA and plasmid-borne cfr, cfr(D), and poxtA2 genes. Microbiol. Spectr., 11.","DOI":"10.1128\/spectrum.02741-22"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1093\/jac\/dkaa125","article-title":"Molecular and functional analysis of the novel cfr(D) linezolid resistance gene identified in Enterococcus faecium","volume":"75","author":"Guerin","year":"2020","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"726","DOI":"10.1038\/s41579-021-00569-w","article-title":"The microbiome-shaping roles of bacteriocins","volume":"19","author":"Heilbronner","year":"2021","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Fioriti, S., Morroni, G., Coccitto, S.N., Brenciani, A., Antonelli, A., Di Pilato, V., Baccani, I., Pollini, S., Cucco, L., and Morelli, A. (2020). Detection of oxazolidinone resistance genes and characterization of genetic environments in Enterococci of swine origin, Italy. Microorganisms, 8.","DOI":"10.3390\/microorganisms8122021"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2459","DOI":"10.1093\/jac\/dkz198","article-title":"Detection of the phenicol-oxazolidinone-tetracycline resistance gene poxtA in Enterococcus faecium and Enterococcus faecalis of food-producing animal origin in China","volume":"74","author":"Lei","year":"2019","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"336","DOI":"10.1016\/j.jgar.2024.01.022","article-title":"Transferable linezolid resistance genes (optrA and poxtA) in enterococci derived from livestock compost at Japanese farms","volume":"36","author":"Fukuda","year":"2024","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref_26","unstructured":"Clinical and Laboratory Standards Institute (2018). Methods for Dilution Antimicrobial Susceptibility Tests for Bacteria that Grow Aerobically, Clinical and Laboratory Standards Institute. [11th ed.]. CLSI standard M07."},{"key":"ref_27","unstructured":"CLSI (2022). Performance Standards for Antimicrobial Susceptibility Testing, Clinical and Laboratory Standards Institute. [32nd ed.]. CLSI supplement M100."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Wick, R.R., Judd, L.M., Gorrie, C.L., and Holt, K.E. (2017). Unicycler: Resolving bacterial genome assemblies from short and long sequencing reads. PLoS Comput. Biol., 13.","DOI":"10.1371\/journal.pcbi.1005595"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"D206","DOI":"10.1093\/nar\/gkt1226","article-title":"The SEED and the Rapid Annotation of microbial genomes using Subsystems Technology (RAST)","volume":"42","author":"Overbeek","year":"2014","journal-title":"Nucleic Acids Res."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"McHugh, M.P., Parcell, B.J., Pettigrew, K.A., Toner, G., Khatamzas, E., El Sakka, N., Karcher, A.M., Walker, J., Weir, R., and Meunier, D. (2022). Presence of optrA-mediated linezolid resistance in multiple lineages and plasmids of Enterococcus faecalis revealed by long read sequencing. Microbiology (Reading), 168.","DOI":"10.1099\/mic.0.001137"}],"container-title":["Antibiotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/4\/337\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:59:25Z","timestamp":1760029165000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6382\/14\/4\/337"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,24]]},"references-count":30,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2025,4]]}},"alternative-id":["antibiotics14040337"],"URL":"https:\/\/doi.org\/10.3390\/antibiotics14040337","relation":{},"ISSN":["2079-6382"],"issn-type":[{"value":"2079-6382","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,24]]}}}