title: Prevalence of clinical isolates of Escherichia coli and Klebsiella spp. producing multiple extended-spectrum beta-lactamases.
abstract: Eleven thousand two hundred seventy-two Escherichia coli, 1109 Klebsiella pneumoniae, 1124 Salmonella enterica, and 602 Klebsiella oxytoca unrelated clinical isolates were obtained between 2001 and 2004 in a university hospital in Salamanca, Spain. One hundred thirteen E. coli (1%), 32 K. pneumoniae (2.9%), 4 K. oxytoca (0.66%), and 5 S. enterica (0.44%) isolates produced extended-spectrum beta-lactamases (ESBLs). We obtained 42.2% of the ESBL-producing isolates from outpatients and 57.8% from inpatients. The most commonly detected ESBLs were CTX-M 14 (43.5% of ESBL-producing isolates), TEM-116 (22.1%), and SHV-2 (15.6%). A CTX-M 27-producing E. coli is 1st reported in Spain in this study. Two (20 isolates, 13%) or 3 (7 isolates, 4.5%) ESBLs were produced by 17.5% of ESBL-producing isolates (27 isolates). The most frequent combinations were CTX-M 14 + TEM-116 (5.7%), SHV-12 + TEM-116 (2.6%), and SHV-2 + CTX-M 14 + TEM-116 (2.6%). Clonal diversity was high even between isolates producing the same combinations of 2 or 3 beta-lactamases.
authors.affiliation: Departamento de Microbiología, Hospital Universitario de Salamanca, 37007 Salamanca, Spain.
authors.forename: Emilio David Valverde
authors.initials: ED
authors.lastname: Romero
authors.forename: Trinidad Parras
authors.initials: TP
authors.lastname: Padilla
authors.forename: Ana Herrero
authors.initials: AH
authors.lastname: Hernández
authors.forename: Rosa Pérez
authors.initials: RP
authors.lastname: Grande
authors.forename: Marta Fernández
authors.initials: MF
authors.lastname: Vázquez
authors.forename: Inmaculada García
authors.initials: IG
authors.lastname: García
authors.forename: José Angel
authors.initials: JA
authors.lastname: García-Rodríguez
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Muñoz Bellido
mesh_terms: D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000201:enzymology / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000453:epidemiology* / Q000382:microbiology; D006785:Hospitals, University; D006801:Humans; D007709:Klebsiella / Q000145:classification / Q000302:isolation & purification*; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology; D019779:Salmonella enterica / Q000302:isolation & purification; D013030:Spain / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000145:classification / Q000235:genetics
chemical_list: D001618:beta-Lactamases