title: Distribution of extended-spectrum β-lactamase types in a Brazilian tertiary hospital.
abstract: BACKGROUND
  Epidemiological data on the prevalence of extended-spectrum β-lactamases (ESBLs) are scarce in Brazil despite the fact that these data are essential for empirical treatment and control measures. The objective of this study was to evaluate the prevalence of different ESBLs by type and distribution in a tertiary hospital in southern Brazil.
  
  
  METHODS
  We evaluated 1,827 enterobacterial isolates between August 2003 and March 2008 isolated from patients at a tertiary hospital. Samples were identified using a Vitek automated system and were confirmed by biochemical testing. The identified ESBL strains were characterized by phenotypic methods, polymerase chain reaction (PCR), and sequencing. Genetic similarities were evaluated by pulsed-field gel electrophoresis.
  
  
  RESULTS
  It was 390 (21.3%) ESBL-producing strains, which expressed the ESBLs CTX-M (292), SHV (84), CTX and SHV (10), TEM (2), and PER (2).
  
  
  CONCLUSIONS
  The prevalence of ESBL-expressing strains was high, especially in Klebsiella pneumoniae and Enterobacter spp. CTX-M was the predominant type of ESBL observed, and its genetic variability indicates a polyclonal distribution.
authors.affiliation: Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
authors.forename: Keite da Silva
authors.initials: Kda S
authors.lastname: Nogueira
authors.affiliation: Faculdades e Instituto de Pesquisa Pelé Pequeno Príncipe, Curitiba, Paraná, Brazil.
authors.forename: Danieli
authors.initials: D
authors.lastname: Conte
authors.affiliation: Secretaria Municipal de Saúde de Curitiba, Prefeitura Municipal de Curitiba, Curitiba, Paraná, Brazil.
authors.forename: Fernanda Valverde
authors.initials: FV
authors.lastname: Maia
authors.affiliation: Hospital de Clínicas, Universidade Federal do Paraná, Curitiba, Paraná, Brazil.
authors.forename: Libera Maria
authors.initials: LM
authors.lastname: Dalla-Costa
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D001938:Brazil; D016521:Electrophoresis, Gel, Pulsed-Field; D004755:Enterobacteriaceae / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D005838:Genotype; D006801:Humans; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D062606:Tertiary Care Centers; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D001426:Bacterial Proteins; D001618:beta-Lactamases