{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,15]],"date-time":"2026-10-15T16:48:12Z","timestamp":1792082892658,"version":"4.4.0"},"reference-count":43,"publisher":"American Society for Microbiology","issue":"1","license":[{"start":{"date-parts":[[2010,1,1]],"date-time":"2010-01-01T00:00:00Z","timestamp":1262304000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Antimicrob Agents Chemother"],"published-print":{"date-parts":[[2010,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    Respiratory infections caused by\n                    <jats:italic>Klebsiella pneumoniae<\/jats:italic>\n                    are characterized by high rates of mortality and morbidity. Management of these infections is often difficult, due to the high frequency of strains that are resistant to multiple antimicrobial agents. Multidrug efflux pumps play a major role as a mechanism of antimicrobial resistance in Gram-negative pathogens. In the present study, we investigated the role of the\n                    <jats:italic>K. pneumoniae<\/jats:italic>\n                    AcrRAB operon in antimicrobial resistance and virulence by using isogenic knockouts deficient in the AcrB component and the AcrR repressor, both derived from the virulent strain 52145R. We demonstrated that the AcrB knockout was more susceptible, not only to quinolones, but also to other antimicrobial agents, including \u03b2-lactams, than the wild-type strain and the AcrR knockout. We further showed that the AcrB knockout was more susceptible to antimicrobial agents present in human bronchoalveolar lavage fluid and to human antimicrobial peptides than the wild-type strain and the AcrR knockout. Finally, the AcrB knockout exhibited a reduced capacity to cause pneumonia in a murine model, in contrast to the wild-type strain. The results of this study suggest that, in addition to contributing to the multidrug resistance phenotype, the AcrAB efflux pump may represent a novel virulence factor required for\n                    <jats:italic>K. pneumoniae<\/jats:italic>\n                    to resist innate immune defense mechanisms of the lung, thus facilitating the onset of pneumonia.\n                  <\/jats:p>","DOI":"10.1128\/aac.00715-09","type":"journal-article","created":{"date-parts":[[2009,10,26]],"date-time":"2009-10-26T21:06:54Z","timestamp":1256591214000},"page":"177-183","update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":423,"title":["<i>Klebsiella pneumoniae<\/i>\n                    AcrAB Efflux Pump Contributes to Antimicrobial Resistance and Virulence"],"prefix":"10.1128","volume":"54","author":[{"given":"Emma","family":"Padilla","sequence":"first","affiliation":[{"name":"Institut Universitari d'Investigacions en Cie\u0300ncies de la Salut (IUNICS) and Departament de Biologia, Universitat de les Illes Balears (UIB), Palma de Mallorca, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Enrique","family":"Llobet","sequence":"additional","affiliation":[{"name":"Fundacio\u0301n Caubet-CIMERA Illes Balears and Centro de Investigacio\u0301n Biome\u0301dica en Red Enfermedades Respiratorias (CIBERES), Bunyola, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Antonio","family":"Dome\u0301nech-Sa\u0301nchez","sequence":"additional","affiliation":[{"name":"Institut Universitari d'Investigacions en Cie\u0300ncies de la Salut (IUNICS) and Departament de Biologia, Universitat de les Illes Balears (UIB), Palma de Mallorca, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luis","family":"Marti\u0301nez-Marti\u0301nez","sequence":"additional","affiliation":[{"name":"Servicio de Microbiologi\u0301a, Hospital Universitario Marques de Valdecilla, and Departmento de Biologi\u0301a Molecular, Universidad de Cantabria, Santander, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jose\u0301 Antonio","family":"Bengoechea","sequence":"additional","affiliation":[{"name":"Fundacio\u0301n Caubet-CIMERA Illes Balears and Centro de Investigacio\u0301n Biome\u0301dica en Red Enfermedades Respiratorias (CIBERES), Bunyola, Spain"},{"name":"Consejo Superior de Investigaciones Cienti\u0301ficas (CSIC), Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sebastia\u0301n","family":"Alberti\u0301","sequence":"additional","affiliation":[{"name":"Institut Universitari d'Investigacions en Cie\u0300ncies de la Salut (IUNICS) and Departament de Biologia, Universitat de les Illes Balears (UIB), Palma de Mallorca, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1164\/ajrccm.160.1.9807041"},{"key":"e_1_3_2_3_2","unstructured":"Current protocols in molecular biology. 1997"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.2000.01956.x"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.14.4.933-951.2001"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1462-5822.2005.00671.x"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1000009"},{"key":"e_1_3_2_8_2","doi-asserted-by":"publisher","DOI":"10.1094\/MPMI.2004.17.1.43"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.72.12.7107-7114.2004"},{"key":"e_1_3_2_10_2","first-page":"2582","volume":"72","year":"2002","unstructured":"Cort\u00e9s, G., N. Borrell, B. de Astorza, C. G\u00f3mez, J. Sauleda, and S. Albert\u00ed. 2002. Molecular analysis of the contribution of the capsular polysaccharide and the lipopolysaccharide O side chain to the virulence of Klebsiella pneumoniae in a murine model of pneumonia. Infect. Immun.72:2582-2590.","journal-title":"Infect. Immun."},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.00356-08"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.41.7.1609"},{"key":"e_1_3_2_13_2","unstructured":"Antimicrob. Agents Chemother. 2001"},{"key":"e_1_3_2_14_2","first-page":"309","volume":"21","year":"2003","unstructured":"Eswaran, J., C. Hughes, and V. Koronakis. 2003. Locking TolC entrance helices to prevent protein translocation by the bacterial type I export apparatus. J. Mol. Biol.21:309-315.","journal-title":"J. Mol. Biol."},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.46.6.2024-2028.2002"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1172\/JCI0215218"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2958.1998.00757.x"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.42.6.2701-2706.2004"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1084\/jem.20020005"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1086\/313915"},{"key":"e_1_3_2_21_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.71.10.5576-5582.2003"},{"key":"e_1_3_2_22_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.42.7.1850"},{"key":"e_1_3_2_23_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.46.12.3926-3932.2002"},{"key":"e_1_3_2_24_2","first-page":"797","volume":"14","year":"1998","unstructured":"Mart\u00ednez-Mart\u00ednez, L., A. Pascual, and G. A. Jacoby. 1998. Quinolone resistance from a transferable plasmid. Lancet14:797-799.","journal-title":"Lancet"},{"key":"e_1_3_2_25_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.46.12.3984-3986.2002"},{"key":"e_1_3_2_26_2","doi-asserted-by":"publisher","DOI":"10.1128\/iai.57.2.546-552.1989"},{"key":"e_1_3_2_27_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbapap.2008.10.004"},{"key":"e_1_3_2_28_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2005.04940.x"},{"key":"e_1_3_2_29_2","doi-asserted-by":"publisher","DOI":"10.1248\/bpb.29.550"},{"key":"e_1_3_2_30_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0004817"},{"key":"e_1_3_2_31_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.2008.06152.x"},{"key":"e_1_3_2_32_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.00072-07"},{"key":"e_1_3_2_33_2","doi-asserted-by":"publisher","DOI":"10.1038\/nrmicro1464"},{"key":"e_1_3_2_34_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.11.4.589"},{"key":"e_1_3_2_35_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dkg388"},{"key":"e_1_3_2_36_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.179.23.7581-7586.1997"},{"key":"e_1_3_2_37_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.47.9.2831-2837.2003"},{"key":"e_1_3_2_38_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.95.4.1829"},{"key":"e_1_3_2_39_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.72.3.1423-1430.2004"},{"key":"e_1_3_2_40_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1365-2958.1995.mmi_17040701.x"},{"key":"e_1_3_2_41_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.187.15.5387-5396.2005"},{"key":"e_1_3_2_42_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.48.4.1295-1299.2004"},{"key":"e_1_3_2_43_2","first-page":"83","volume":"5","year":"1965","unstructured":"Westphal, O., and K. Jann. 1965. Bacterial lipopolysaccharides: extraction with phenol-water and further applications of the procedure. Methods Carbohydr. Chem.5:83-91.","journal-title":"Methods Carbohydr. Chem."},{"key":"e_1_3_2_44_2","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1016\/S0580-9517(08)70642-1","volume":"5","year":"1971","unstructured":"Wilkinson, J. F., and I. W. Sutherland. 1971. Chemical extraction methods of microbial cells. Methods Microbiol.5B:345-383.","journal-title":"Methods Microbiol."}],"container-title":["Antimicrobial Agents and Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.00715-09","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.00715-09","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T15:18:42Z","timestamp":1645456722000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.00715-09"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2010,1]]},"references-count":43,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2010,1]]}},"alternative-id":["10.1128\/AAC.00715-09"],"URL":"https:\/\/doi.org\/10.1128\/aac.00715-09","relation":{"has-review":[{"id-type":"doi","id":"10.3410\/f.1728961.1246060","asserted-by":"object"}]},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[2010,1]]},"assertion":[{"value":"2009-05-27","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2009-10-20","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2010-01-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}