{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T01:18:28Z","timestamp":1791249508636,"version":"4.1.0"},"reference-count":0,"publisher":"SAGE Publications","issue":"3","license":[{"start":{"date-parts":[[1999,10,1]],"date-time":"1999-10-01T00:00:00Z","timestamp":938736000000},"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":[[1999,10]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    Resistance to extended-spectrum cephalosporins within members of the family Enterobacteriaceae occurs virtually world-wide. Nevertheless, nothing was known about this problem among isolates from Mexico. To address this issue, we studied oximino-cephalosporin resistant isolates of\n                    <jats:italic toggle=\"yes\">Klebsiella pneumoniae<\/jats:italic>\n                    (13),\n                    <jats:italic toggle=\"yes\">Escherichia coli<\/jats:italic>\n                    (7), and\n                    <jats:italic toggle=\"yes\">Enterobacter cloacae<\/jats:italic>\n                    (23) recovered from patients in Mexico City hospitals during 1990 to 1992. In the presence of clavulanic acid, these strains increased susceptibility to cefotaxime and ceftazidime (MIC\n                    <jats:sub>90<\/jats:sub>\n                    64 and &gt;256 \u03bcg\/ml, respectively). The ability of these isolates to transfer resistance to both antibiotics by conjugation was most successfully demonstrated by\n                    <jats:italic toggle=\"yes\">K. pneumoniae<\/jats:italic>\n                    . In all the clinical isolates tested, the largest plasmid coded for the extended-spectrum \u03b2-lactamases (ESBL). Characteristics of pI, by isoelectric focusing (IEF)\/bioassay and DNA hybridization with specific probes of TEM and SHV, indicated that in most of the clinical isolates and all transconjugates, the most frequent \u03b2-lactamase coded were SHV-derived (20 strains as 41% of isolates) and a plasmid-encoded \u03b2-lactamase (12 strains as 25% of isolates) (with a pI of &gt;8.2), which is not related to TEM\/SHV. Apparently, isolates from Mexico show characteristics similar to isolates from other geographic areas. The type of \u03b2-lactamases coded in these resistant isolates is documented for the first time in Mexico.\n                  <\/jats:p>","DOI":"10.1089\/mdr.1999.5.189","type":"journal-article","created":{"date-parts":[[2009,1,29]],"date-time":"2009-01-29T12:41:03Z","timestamp":1233232863000},"page":"189-193","source":"Crossref","is-referenced-by-count":17,"title":["Extended-Spectrum \u03b2-Lactamases in Clinical Isolates of Enterobacteria in Mexico"],"prefix":"10.1177","volume":"5","author":[{"given":"J.","family":"Silva","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C.","family":"Aguilar","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Z.","family":"Becerra","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"F.","family":"L\u00d3PEZ-ANTU\u00d1ANO","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R.","family":"GARC\u00cdA","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","published-online":{"date-parts":[[1999,10]]},"container-title":["Microbial Drug Resistance"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1089\/mdr.1999.5.189","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1089\/mdr.1999.5.189","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T18:13:38Z","timestamp":1770747218000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/full\/10.1089\/mdr.1999.5.189"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1999,10]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1999,10]]}},"alternative-id":["10.1089\/mdr.1999.5.189"],"URL":"https:\/\/doi.org\/10.1089\/mdr.1999.5.189","relation":{},"ISSN":["1076-6294","1931-8448"],"issn-type":[{"value":"1076-6294","type":"print"},{"value":"1931-8448","type":"electronic"}],"subject":[],"published":{"date-parts":[[1999,10]]}}}