{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,15]],"date-time":"2026-07-15T23:56:30Z","timestamp":1784159790600,"version":"3.55.0"},"reference-count":26,"publisher":"SAGE Publications","issue":"1","license":[{"start":{"date-parts":[[2010,3,1]],"date-time":"2010-03-01T00:00:00Z","timestamp":1267401600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microbial Drug Resistance"],"published-print":{"date-parts":[[2010,3]]},"abstract":"<jats:p>\n                    The prevalence and molecular types of extended-spectrum beta-lactamases (ESBLs) were determined during a 1-year period in unselected clinical nonduplicate isolates of\n                    <jats:italic toggle=\"yes\">Escherichia coli<\/jats:italic>\n                    (\n                    <jats:italic toggle=\"yes\">n<\/jats:italic>\n                    \u2009=\u20091,738),\n                    <jats:italic toggle=\"yes\">Klebsiella pneumoniae<\/jats:italic>\n                    (\n                    <jats:italic toggle=\"yes\">n<\/jats:italic>\n                    \u2009=\u2009436), and\n                    <jats:italic toggle=\"yes\">Klebsiella oxytoca<\/jats:italic>\n                    (\n                    <jats:italic toggle=\"yes\">n<\/jats:italic>\n                    \u2009=\u2009208), cultured at the University Medical Centre Nijmegen, The Netherlands. Isolates identified as ESBL producer by the Phoenix automated system were collected prospectively and subjected to molecular analysis for the most common ESBLs TEM, SHV, and CTX-M, as well as OXA and GES. Both the Etest ESBL and double-disk synergy test were performed as confirmatory tests. The estimated prevalence of ESBLs was 2.1% in\n                    <jats:italic toggle=\"yes\">E. coli<\/jats:italic>\n                    , 5.2% in\n                    <jats:italic toggle=\"yes\">K. pneumoniae<\/jats:italic>\n                    , and 2.4% in\n                    <jats:italic toggle=\"yes\">K. oxytoca<\/jats:italic>\n                    . TEM-12 and -26, SHV-5 and -12, and CTX-M groups 1 and 9 were the most frequent ESBLs found. Isolates identified as ESBLs by the Phoenix were confirmed by polymerase chain reaction (PCR) in only 42%. In ESBL PCR-positive\n                    <jats:italic toggle=\"yes\">E. coli<\/jats:italic>\n                    and\n                    <jats:italic toggle=\"yes\">K. pneumoniae<\/jats:italic>\n                    , both confirmatory tests were positive in 95% of the isolates. In 28% of the Etest and 13% of the double-disk synergy test-positive isolates, PCR could not detect any ESBL gene. In these cases, other resistance mechanisms may play a role. Confirmatory tests were unreliable for\n                    <jats:italic toggle=\"yes\">K. oxytoca<\/jats:italic>\n                    . A previously described mutation in the K1 enzyme was detected in one ceftazidime-resistant\n                    <jats:italic toggle=\"yes\">K. oxytoca<\/jats:italic>\n                    . The prevalence of ESBLs in The Netherlands is increasing. The predominant molecular types of ESBLs detected were comparable to other studies. Phoenix ESBL results need to be confirmed as advocated by ESBL detection guidelines.\n                  <\/jats:p>","DOI":"10.1089\/mdr.2009.0107","type":"journal-article","created":{"date-parts":[[2009,12,14]],"date-time":"2009-12-14T18:50:16Z","timestamp":1260816616000},"page":"55-60","source":"Crossref","is-referenced-by-count":12,"title":["Prevalence, Molecular Characterization, and Phenotypic Confirmation of Extended-Spectrum Beta-Lactamases in\n                    <i>Escherichia coli<\/i>\n                    ,\n                    <i>Klebsiella pneumoniae<\/i>\n                    , and\n                    <i>Klebsiella oxytoca<\/i>\n                    at the Radboud University Nijmegen Medical Centre in The Netherlands"],"prefix":"10.1177","volume":"16","author":[{"given":"Patrick D.J.","family":"Sturm","sequence":"first","affiliation":[{"name":"Radboud University Nijmegen Medical Center","place":["The Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Els T.M.","family":"Bochum","sequence":"additional","affiliation":[{"name":"Radboud University Nijmegen Medical Center","place":["The Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sacha V.M.","family":"van Mook-Vermulst","sequence":"additional","affiliation":[{"name":"Radboud University Nijmegen Medical Center","place":["The Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cindy","family":"Handgraaf","sequence":"additional","affiliation":[{"name":"Radboud University Nijmegen Medical Center","place":["The Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Twan","family":"Klaassen","sequence":"additional","affiliation":[{"name":"Radboud University Nijmegen Medical Center","place":["The Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Willem J.G.","family":"Melchers","sequence":"additional","affiliation":[{"name":"Radboud University Nijmegen Medical Center","place":["The Netherlands"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[2010,3]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"crossref","first-page":"3012","DOI":"10.1128\/JCM.01112-06","article-title":"Widely distributed and predominant CTX-M extended-spectrum beta-lactamases in Amsterdam, The Netherlands","volume":"44","author":"Al Naiemi N.","year":"2006","unstructured":"Al Naiemi N., , Bart A., , de J., , Vandenbroucke-Grauls C.M., , Rietra P.J., , bets-Ossenkopp Y.J., , Wever P.C., , Spanjaard L., , Bos A.J., , Duim B. 2006. Widely distributed and predominant CTX-M extended-spectrum beta-lactamases in Amsterdam, The Netherlands. J. Clin. Microbiol., 44:3012\u20133014.","journal-title":"J. Clin. Microbiol."},{"key":"e_1_3_2_3_2","doi-asserted-by":"crossref","first-page":"2230","DOI":"10.1128\/AAC.44.8.2230-2230.2000","article-title":"Are SHV beta-lactamases universal in Klebsiella pneumoniae?","volume":"44","author":"Babini G.S.","year":"2000","unstructured":"Babini G.S., , Livermore D.M. 2000. Are SHV beta-lactamases universal in Klebsiella pneumoniae? Antimicrob. Agents Chemother., 44:2230.","journal-title":"Antimicrob. Agents Chemother."},{"key":"e_1_3_2_4_2","doi-asserted-by":"crossref","first-page":"2269","DOI":"10.1128\/AAC.45.8.2269-2275.2001","article-title":"Novel cefotaximase (CTX-M-16) with increased catalytic efficiency due to substitution Asp-240\u2192Gly","volume":"45","author":"Bonnet R.","year":"2001","unstructured":"Bonnet R., , Dutour C., , Sampaio J.L., , Chanal C., , Sirot D., , Labia R., , De C.C., , Sirot J. 2001. Novel cefotaximase (CTX-M-16) with increased catalytic efficiency due to substitution Asp-240\u2192Gly. Antimicrob. Agents Chemother., 45:2269\u20132275.","journal-title":"Antimicrob. Agents Chemother."},{"issue":"1","key":"e_1_3_2_5_2","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1111\/j.1469-0691.2007.01848.x","article-title":"Extended-spectrum beta-lactamases in North America, 1987\u20132006","volume":"14","author":"Bush K.","year":"2008","unstructured":"Bush K. 2008. Extended-spectrum beta-lactamases in North America, 1987\u20132006. Clin. Microbiol. Infect., 14,Suppl 1:134\u2013143.","journal-title":"Clin. Microbiol. Infect."},{"key":"e_1_3_2_6_2","doi-asserted-by":"crossref","first-page":"4228","DOI":"10.1128\/JCM.38.11.4228-4232.2000","article-title":"Detection of extended-spectrum beta-lactamases in klebsiellae with the Oxoid combination disk method","volume":"38","author":"Carter M.W.","year":"2000","unstructured":"Carter M.W., , Oakton K.J., , Warner M., , Livermore D.M. 2000. Detection of extended-spectrum beta-lactamases in klebsiellae with the Oxoid combination disk method. J. Clin. Microbiol., 38:4228\u20134232.","journal-title":"J. Clin. Microbiol."},{"key":"e_1_3_2_7_2","volume-title":"Performance standards for antimicrobial susceptibility testing: Seventeenth Informational Supplement, M100-S17","author":"[CLSI] Clinical, Laboratory Standards Institute","year":"2007","unstructured":"[CLSI] Clinical, Laboratory Standards Institute. 2007. Performance standards for antimicrobial susceptibility testing: Seventeenth Informational Supplement, M100-S17. Wayne, Pennsylvania."},{"key":"e_1_3_2_8_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.2807\/ese.13.47.19044-en","article-title":"Increasing prevalence of ESBL-producing Enterobacteriaceae in Europe","volume":"13","author":"Coque T.M.","year":"2008","unstructured":"Coque T.M., , Baquero F., , Canton R. 2008. Increasing prevalence of ESBL-producing Enterobacteriaceae in Europe. Eur. Surveill., 13:1\u201311.","journal-title":"Eur. Surveill."},{"key":"e_1_3_2_9_2","unstructured":"[EARSS] European Antimicrobial Resistance Surveillance System. 2008. 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Infection, 27:348\u2013354.","journal-title":"Infection"},{"key":"e_1_3_2_25_2","article-title":"Consumption of antimicrobial agents and antimicrobial resistance among medically important bacteria in The Netherlands","author":"[SWAB] Stichting Werkgroep AntibioticaBeleid. 2009","year":"2008","unstructured":"[SWAB] Stichting Werkgroep AntibioticaBeleid. 2009. Consumption of antimicrobial agents and antimicrobial resistance among medically important bacteria in The Netherlands. NethMap, 2008. www.swab.nl. 2009 Nov 18.","journal-title":"NethMap"},{"key":"e_1_3_2_26_2","doi-asserted-by":"crossref","first-page":"1167","DOI":"10.1128\/JCM.01988-06","article-title":"Detection of extended-spectrum beta-lactamases among Enterobacteriaceae by use of semiautomated microbiology systems and manual detection procedures","volume":"45","author":"Wiegand I.","year":"2007","unstructured":"Wiegand I., , Geiss H.K., , Mack D., , Sturenburg E., , Seifert H. 2007. Detection of extended-spectrum beta-lactamases among Enterobacteriaceae by use of semiautomated microbiology systems and manual detection procedures. J. Clin. Microbiol., 45:1167\u20131174.","journal-title":"J. Clin. Microbiol."},{"key":"e_1_3_2_27_2","doi-asserted-by":"crossref","first-page":"755","DOI":"10.1093\/jac\/47.6.755","article-title":"Outer membrane protein change combined with co-existing TEM-1 and SHV-1 beta-lactamases lead to false identification of ESBL-producing Klebsiella pneumoniae","volume":"47","author":"Wu T.L.","year":"2001","unstructured":"Wu T.L., , Siu L.K., , Su L.H., , Lauderdale T.L., , Lin F.M., , Leu H.S., , Lin T.Y., , Ho M. 2001. Outer membrane protein change combined with co-existing TEM-1 and SHV-1 beta-lactamases lead to false identification of ESBL-producing Klebsiella pneumoniae. J. Antimicrob. Chemother., 47:755\u2013761.","journal-title":"J. Antimicrob. 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