title: Long-term study of the frequency of Escherichia coli and Klebsiella pneumoniae isolates producing extended-spectrum beta-lactamases.
abstract: In total, 438 (1.7%) Escherichia coli and 125 (3.98%) Klebsiella pneumoniae isolates were found to be producers of extended-spectrum beta-lactamase (ESBL) during 1995-2003 in southern Spain. There was a significant increase in the frequency of ESBL-producing E. coli isolates, from < 0.36% before 1999 to 4.8% in 2003, while the frequency of ESBL-producing K. pneumoniae isolates decreased during the same period. The most common ESBLs detected in K. pneumoniae were SHV type, whereas both CTX-M and SHV types were detected in E. coli. In addition, E. coli isolates showed greater clonal diversity (84 distinct REP-PCR patterns, compared with five in K. pneumoniae), fewer enzymes per isolate, and a higher number of isolates recovered from outpatients. These differences may have implications for the control measures that should be used for these two microorganisms.
authors: Department of Microbiology, Service of Internal Medicine, Hospital Universitario Virgen Macarena, Seville, Spain. lromeroperez@us.es
authors: L
authors: L
authors: Romero
authors: L
authors: L
authors: López
authors: J
authors: J
authors: Rodríguez-Baño
authors: J
authors: J
authors: Ramón Hernández
authors: L
authors: L
authors: Martínez-Martínez
authors: A
authors: A
authors: Pascual
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D018550:Cephalosporin Resistance; D002648:Child; D002675:Child, Preschool; D004926:Escherichia coli / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007710:Klebsiella Infections / Q000453:epidemiology* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000145:classification / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D013030:Spain / Q000453:epidemiology; D013997:Time Factors; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases