{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T19:27:12Z","timestamp":1777922832914,"version":"3.51.4"},"reference-count":14,"publisher":"SAGE Publications","issue":"7","license":[{"start":{"date-parts":[[2017,3,13]],"date-time":"2017-03-13T00:00:00Z","timestamp":1489363200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Microbial Drug Resistance"],"published-print":{"date-parts":[[2017,10,1]]},"abstract":"\n Objective:<\/jats:title>\n \n The objective was to evaluate the cytotoxic effect associated with overexpression of multiple Qnr-like plasmid-mediated quinolone resistance (PMQR) mechanisms in\n Escherichia coli<\/jats:italic>\n .\n <\/jats:p>\n <\/jats:sec>\n \n Methods:<\/jats:title>\n \n Coding regions of different PMQR genes (\n qnrA1<\/jats:italic>\n ,\n qnrB1<\/jats:italic>\n ,\n qnrC<\/jats:italic>\n ,\n qnrD1<\/jats:italic>\n ,\n qnrS1<\/jats:italic>\n , and\n qepA2<\/jats:italic>\n ) and\n efsqnr<\/jats:italic>\n were cloned into pET29a(+) vector and overexpressed in\n E. coli<\/jats:italic>\n BL21.\n E. coli<\/jats:italic>\n BL21 with and without an empty pET29a(+) vector were used as controls. The cytotoxic effect associated with PMQR mechanism overexpression was determined by transmission electron microscopy and viability assays.\n <\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n \n Overexpressed\n qnr<\/jats:italic>\n genes produced loss of bacterial viability in the range of 77\u201397% compared with the controls, comparable with loss of viability associated with EfsQnr overexpression (97%). No loss of viability was observed in\n E. coli<\/jats:italic>\n overexpressing QepA2. In transmission electron microscopy assays, signs of cytotoxicity were observed in\n E. coli<\/jats:italic>\n cells overexpressing EfsQnr and Qnr proteins (30\u201345% of the bacterial population showed morphological changes). Morphological changes were observed in less than 5% of bacterial populations from the control strains and\n E. coli<\/jats:italic>\n overexpressing QepA2.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions:<\/jats:title>\n \n Overexpression of\n qnr<\/jats:italic>\n genes produces a cytotoxic cellular and structural effect in\n E. coli<\/jats:italic>\n , the magnitude of which varies depending on the family of Qnr proteins.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1089\/mdr.2016.0245","type":"journal-article","created":{"date-parts":[[2017,3,13]],"date-time":"2017-03-13T13:59:14Z","timestamp":1489413554000},"page":"822-825","update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":3,"title":["Cytotoxic Effect Associated with Overexpression of QNR Proteins in\n Escherichia coli<\/i>"],"prefix":"10.1177","volume":"23","author":[{"given":"Jes\u00fas","family":"Machuca","sequence":"first","affiliation":[{"name":"Hospital Universitario Virgen Macarena","place":["Spain"]},{"name":"Institute of Biomedicine of Seville (IBiS)","place":["Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paula","family":"Diaz de Alba","sequence":"additional","affiliation":[{"name":"Hospital Universitario Virgen Macarena","place":["Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Esther","family":"Recacha","sequence":"additional","affiliation":[{"name":"Hospital Universitario Virgen Macarena","place":["Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"\u00c1lvaro","family":"Pascual","sequence":"additional","affiliation":[{"name":"Hospital Universitario Virgen Macarena","place":["Spain"]},{"name":"Institute of Biomedicine of Seville (IBiS)","place":["Spain"]},{"name":"University of Seville","place":["Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jos\u00e9 Manuel","family":"Rodriguez-Martinez","sequence":"additional","affiliation":[{"name":"Institute of Biomedicine of Seville (IBiS)","place":["Spain"]},{"name":"University of Seville","place":["Spain"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2017,3,13]]},"reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1111\/nyas.12830"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1007\/s10156-010-0120-2"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.00016-09"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.01158-10"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.resmic.2014.05.033"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.01205-08"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkp111"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M111.226936"},{"key":"e_1_3_3_10_2","unstructured":"Clinical and Laboratory Standards Institute. 2014. Performance Standards for Antimicrobial Susceptibility Testing: twenty-fifth Informational Supplement M100-S25. CLSI Wayne PA."},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dku308"},{"key":"e_1_3_3_12_2","first-page":"2","article-title":"Plasmid-mediated quinolone resistance","author":"Jacoby G.A.","year":"2014","unstructured":"Jacoby G.A., , Strahilevitz J., , and Hooper D.C.. 2014. Plasmid-mediated quinolone resistance. Microbiol. Spectr. 2.","journal-title":"Microbiol. Spectr."},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.00991-10"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dks326"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.05142-11"}],"container-title":["Microbial Drug Resistance"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1089\/mdr.2016.0245","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1089\/mdr.2016.0245","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1089\/mdr.2016.0245","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T20:31:13Z","timestamp":1777667473000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1089\/mdr.2016.0245"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,3,13]]},"references-count":14,"journal-issue":{"issue":"7","published-print":{"date-parts":[[2017,10,1]]}},"alternative-id":["10.1089\/mdr.2016.0245"],"URL":"https:\/\/doi.org\/10.1089\/mdr.2016.0245","relation":{},"ISSN":["1076-6294","1931-8448"],"issn-type":[{"value":"1076-6294","type":"print"},{"value":"1931-8448","type":"electronic"}],"subject":[],"published":{"date-parts":[[2017,3,13]]}}}