{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T18:07:40Z","timestamp":1792001260857,"version":"4.4.0"},"reference-count":36,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2021,2,22]],"date-time":"2021-02-22T00:00:00Z","timestamp":1613952000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antibiotics"],"abstract":"<jats:p>The aim of this study was to map and investigate linezolid resistance mechanisms in linezolid-resistant enterococci in the Czech Republic from 2009 to 2019. Altogether, 1442 isolates of Enterococcus faecium and Enterococcus faecalis were examined in the National Reference Laboratory for Antibiotics. Among them, 8% of isolates (n = 115) were resistant to linezolid (E. faecium\/n = 106, E. faecalis\/n = 9). Only three strains of E. faecium were resistant to tigecycline, 72.6% of isolates were resistant to vancomycin. One isolate of E. faecium harbored the cfr gene. The majority (87%, n = 11) of E. faecium strains were resistant to linezolid because of the mutation G2576T in the domain V of the 23S rRNA. This mutation was detected also in two strains of E. faecalis. The presence of the optrA gene was the dominant mechanism of linezolid resistance in E. faecalis isolates. None of enterococci contained cfrB, poxtA genes, or any amino acid mutation in genes encoding ribosomal proteins. No mechanism of resistance was identified in 4 out of 106 E. faecium linezolid resistant isolates in this study. Seventeen sequence types (STs) including four novel STs were identified in this work. Clonal complex CC17 was found in all E. faecium isolates.<\/jats:p>","DOI":"10.3390\/antibiotics10020219","type":"journal-article","created":{"date-parts":[[2021,2,22]],"date-time":"2021-02-22T14:23:27Z","timestamp":1614003807000},"page":"219","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Spread of Linezolid-Resistant Enterococcus spp. in Human Clinical Isolates in the Czech Republic"],"prefix":"10.3390","volume":"10","author":[{"given":"Lucia","family":"Mali\u0161ov\u00e1","sequence":"first","affiliation":[{"name":"National Reference Laboratory for Antibiotics, Centre for Epidemiology and Microbiology, National Institute of Public Health, 10000 Prague, Czech Republic"},{"name":"Department of Microbiology, 3rd Faculty of Medicine Charles University, University Hospital Kralovske Vinohrady and National Institute of Public Health, 10000 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vladislav","family":"Jakub\u016f","sequence":"additional","affiliation":[{"name":"National Reference Laboratory for Antibiotics, Centre for Epidemiology and Microbiology, National Institute of Public Health, 10000 Prague, Czech Republic"},{"name":"Department of Microbiology, 3rd Faculty of Medicine Charles University, University Hospital Kralovske Vinohrady and National Institute of Public Health, 10000 Prague, Czech Republic"},{"name":"Department of Clinical Microbiology, Faculty of Medicine and University Hospital, Charles University, 53002 Hradec Kralove, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katar\u00edna","family":"Pomorsk\u00e1","sequence":"additional","affiliation":[{"name":"National Reference Laboratory for Antibiotics, Centre for Epidemiology and Microbiology, National Institute of Public Health, 10000 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2238-1599","authenticated-orcid":false,"given":"Martin","family":"Mus\u00edlek","sequence":"additional","affiliation":[{"name":"National Reference Laboratory for Meningococcal Infections, Centre for Epidemiology and Microbiology, National Institute of Public Health, 10000 Prague, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3868-0545","authenticated-orcid":false,"given":"Helena","family":"\u017demli\u010dkov\u00e1","sequence":"additional","affiliation":[{"name":"National Reference Laboratory for Antibiotics, Centre for Epidemiology and Microbiology, National Institute of Public Health, 10000 Prague, Czech Republic"},{"name":"Department of Microbiology, 3rd Faculty of Medicine Charles University, University Hospital Kralovske Vinohrady and National Institute of Public Health, 10000 Prague, Czech Republic"},{"name":"Department of Clinical Microbiology, Faculty of Medicine and University Hospital, Charles University, 53002 Hradec Kralove, Czech Republic"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,2,22]]},"reference":[{"key":"ref_1","first-page":"788","article-title":"Global Emergence and Dissemination of Enterococci as Nosocomial Pathogens: Attack of the Clones?","volume":"26","author":"Prieto","year":"2016","journal-title":"Front. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"266","DOI":"10.1038\/nrmicro2761","article-title":"The rise of the Enterococcus: Beyond vancomycin resistance","volume":"10","author":"Arias","year":"2012","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1128\/CMR.3.1.46","article-title":"The life and times of the Enterococcus","volume":"3","author":"Murray","year":"1990","journal-title":"Clin. Microbiol. Rev."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.drup.2014.04.002","article-title":"Linezolid update: Stable in vitro activity following more than a decade of clinical use and summary of associated resistance mechanisms","volume":"17","author":"Mendes","year":"2014","journal-title":"Drug Resist. Updates"},{"key":"ref_5","first-page":"1480","article-title":"Dose Dependence of Emergence of Resistance to Linezolid in Enterococcus faecalis In Vivo","volume":"10","author":"Massias","year":"2007","journal-title":"J. Infect. Dis."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"3917","DOI":"10.1128\/AAC.00419-12","article-title":"Transferable plasmid-mediated resistance to linezolid due to cfr in a human clinical isolate of Enterococcus faecalis","volume":"56","author":"Diaz","year":"2012","journal-title":"Antimicrob. Agents 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\u2013oxazolidinone\u2013tetracycline 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","first-page":"128","DOI":"10.1016\/j.jgar.2015.02.007","article-title":"Increased frequency of linezolid resistance among clinical Enterococcus faecium isolates from German hospital patients","volume":"3","author":"Klare","year":"2015","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/j.diagmicrobio.2013.08.012","article-title":"Linezolid resistance in Enterococcus faecium isolated in Ontario, Canada","volume":"77","author":"Patel","year":"2013","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2554","DOI":"10.1128\/JCM.00245-07","article-title":"The emergence and importation of diverse genotypes of methicillin-resistant Staphylococcus aureus (MRSA) harboring the Panton-Valentine leukocidin gene (pvl) reveal that pvl is a poor marker for community-acquired MRSA strains in Ireland","volume":"45","author":"Rossney","year":"2007","journal-title":"J. Clin. Microbiol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Bender, J.K., Fleige, C., Klare, I., Fiedler, S., Mischnik, A., Mutters, N.T., Dingle, K.E., and Werner, G. (2016). Detection of a cfr(B) Variantin German Enterococcus faecium Clinical Isolates and the Impact on Linezolid Resistance in Enterococcuss pp. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0167042"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"105977","DOI":"10.1016\/j.ijantimicag.2020.105977","article-title":"Spanish Linezolid-Resistant Enterococci Collaborating Group, Interregional spread in Spain of linezolid-resistant Enterococcus spp. isolates carrying the optrA and poxtA genes","volume":"55","author":"Moure","year":"2020","journal-title":"Int. J. Antimicrob. Agents"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.drup.2018.10.002","article-title":"Update on prevalence and mechanisms of resistance to linezolid, tigecycline and daptomycin in enterococci in Europe: Towards a common nomenclature","volume":"40","author":"Bender","year":"2018","journal-title":"Drug Resist. Updates"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2154","DOI":"10.1128\/AAC.45.7.2154-2156.2001","article-title":"Resistance to linezolid: Characterization of mutations in rRNA and comparison of their occurrences in vancomycin-resistant enterococci","volume":"45","author":"Prystowsky","year":"2001","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1819","DOI":"10.1093\/jac\/dks146","article-title":"Intensive care unit dissemination of multiple clones of linezolid-resistant Enterococcus faecalis and Enterococcus faecium","volume":"67","author":"Ntokou","year":"2012","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4656","DOI":"10.1128\/AAC.00279-12","article-title":"Molecular epidemiology of Staphylococcus epidermidis clinical isolates from U.S. hospitals","volume":"56","author":"Mendes","year":"2012","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_18","first-page":"678","article-title":"Detection of linezolid resistance due to the optrA gene in Enterococcus faecalis from poultry meat from the American continent (Colombia)","volume":"72","author":"Cavaco","year":"2017","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1016\/j.jgar.2017.05.002","article-title":"Detection of the optrA gene in a clinical ST16 Enterococcus faecalis isolate in Denmark","volume":"10","author":"Vorobieva","year":"2017","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Ruiz-Ripa, L., Fe\u00dfler, A.T., Hanke, D., Eichhorn, I., Azcona-Guti\u00e9rrez, J.M., P\u00e9rez-Moreno, M.O., Seral, C., Aspiroz, C., Alonso, C.A., and Torres, L. (2020). Mechanisms of Linezolid Resistance Among Enterococci of Clinical Origin in Spain-Detection of optrA- and cfr(D)-Carrying E. faecalis. Microorganisms, 8.","DOI":"10.3390\/microorganisms8081155"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2461","DOI":"10.1093\/jac\/dkz155","article-title":"Detection in Greece of a clinical Enterococcus faecium isolate carrying the novel oxazolidinone resistance gene poxtA","volume":"8","author":"Papagiannitsis","year":"2019","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"15500","DOI":"10.1038\/s41598-019-51918-y","article-title":"Analysis of combined resistance to oxazolidinones and phenicols among bacteria from dogs fed with raw meat\/vegetables and the respective food items","volume":"1","author":"Wu","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1016\/j.mimet.2015.08.019","article-title":"Evaluation of DiversiLab\u00ae, MLST and PFGE typing for discriminating clinical Enterococcus faecium isolates","volume":"118","author":"Werner","year":"2015","journal-title":"J. Microbiol. Methods"},{"key":"ref_24","first-page":"2155","article-title":"Molecular Typing of Enterococci\/VRE","volume":"10","author":"Werner","year":"2013","journal-title":"Werner. J. Bacteriol. Parasitol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1186\/s13756-019-0598-z","article-title":"Hospital outbreak caused by linezolid resistant Enterococcus faecium in Upper Austria","volume":"8","author":"Kerschner","year":"2019","journal-title":"Antimicrob. Resist. Infect. Control"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1704","DOI":"10.1093\/jac\/dkaa075","article-title":"Linezolid resistance in Enterococcus faecium and Enterococcus faecalis from hospitalized patients in Ireland: High prevalence of the MDR genes optrA and poxtA in isolates with diverse genetic backgrounds","volume":"75","author":"Egan","year":"2020","journal-title":"J. Antimicrob. Chemother."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/j.nmni.2017.12.001","article-title":"Genetic characteristics of VanA-type vancomycin-resistant Enterococcus faecalis and Enterococcus faecium in Cuba","volume":"21","author":"Aung","year":"2018","journal-title":"New Microbes New Infect."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Wang, S., Guo, Y., Lv, J., Qi, X., Li, D., Chen, Z., Zhang, X., Wang, L., and Yu, F. (2016). Characteristic of Enterococcus faecium clinical isolates with quinupristin\/dalfopristin resistance in China. BMC Microbiol., 16.","DOI":"10.1186\/s12866-016-0863-8"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1128\/JCM.01704-06","article-title":"Clonal structure of Enterococcus faecalis isolated from Polish hospitals: The characterization of epidemic clones","volume":"1","author":"Kawalec","year":"2007","journal-title":"J. Clin. Microbiol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2220","DOI":"10.1128\/JCM.02596-05","article-title":"Multilocus sequence typing scheme for Enterococcus faecalis reveals hospital-adapted genetic complexes in a background of high rates of recombination","volume":"44","author":"Bonten","year":"2006","journal-title":"J. Clin. Microbiol."},{"key":"ref_31","first-page":"e000350","article-title":"Comparative genomics of global optrA-carrying Enterococcus faecalis uncovers a common chromosomal hotspot for optrA acquisition within a diversity of core and accessory genomes","volume":"6","author":"Freitas","year":"2020","journal-title":"Microb. Genom."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1118","DOI":"10.1093\/jac\/dkv438","article-title":"Detection in Italy of two clinical Enterococcus faecium isolates carrying both the oxazolidinone and phenicol resistance gene optrA and a silent multiresistance gene cfr","volume":"71","author":"Brenciani","year":"2016","journal-title":"J. Antimicrob. Chemother"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Tian, Y., Li, T., Zhu, Y., Wang, B., Zou, X., and Li, M. (2014). Mechanisms of linezolid resistance in staphylococciand enterococci isolated from two teaching hospitals in Shanghai, China. BMC Microbiol., 14.","DOI":"10.1186\/s12866-014-0292-5"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1016\/j.gene.2018.01.008","article-title":"Whole transcriptome analysis reveals potential novel mechanisms of low-level linezolid resistance in Enterococcus faecalis","volume":"647","author":"Hua","year":"2018","journal-title":"Gene"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"821","DOI":"10.1086\/650574","article-title":"Resistance to Linezolid Is Mediated by the cfr Gene in the First Report of an Outbreak of Linezolid-Resistant Staphylococcus aureus","volume":"50","author":"Morales","year":"2010","journal-title":"Clin. Inf. Dis."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1007\/978-1-60327-999-4_11","article-title":"Multilocus Sequence Typing","volume":"551","author":"Maiden","year":"2009","journal-title":"Methods Mol. Biol."}],"container-title":["Antibiotics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-6382\/10\/2\/219\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:28:08Z","timestamp":1760160488000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-6382\/10\/2\/219"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,2,22]]},"references-count":36,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["antibiotics10020219"],"URL":"https:\/\/doi.org\/10.3390\/antibiotics10020219","relation":{},"ISSN":["2079-6382"],"issn-type":[{"value":"2079-6382","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,2,22]]}}}