title: Nosocomial and community infections due to class A extended-spectrum β-lactamase (ESBLA)-producing Escherichia coli and Klebsiella spp. in southern Brazil.
abstract: OBJECTIVE
  To determine the prevalence of class A extended spectrum β-lactamases (ESBL)-producing Escherichia coli and Klebsiella spp., and to investigate clonality among ESBL-producing isolates of nosocomial and community infections.
  
  
  METHODS
  The study involved 354 nosocomial infections samples and 992 community infections samples, obtained between 2003 and 2006 at Caxias do Sul, RS. The detection of ESBL was performed by the disk-diffusion test. Presence of blaCTX-M, blaSHV and blaTEM β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis analysis.
  
  
  RESULTS
  Higher frequency of ESBL-producing isolates were detected among nosocomial samples of E. coli (6.7%) and Klebsiella (43.7%), than those obtained from community infections (0.4% and 2.6%). blaTEM and blaCTX were the most prevalent ESBL gene families in both E. coli and Klebsiella isolates. Different pulsotypes were obtained among ESBL-producing E. coli and 11 clones for Klebsiella spp., which occurred over the years and in different hospital wards. Among ESBL-producing K. pneumoniae, 74.3% transferred ESBL genes by conjugation and exhibited concomitant decreased aminoglycosides susceptibility.
  
  
  CONCLUSIONS
  ESBL-producing E. coli, and especially K. pneumoniae are essentially a nosocomial problem, and their dissemination to the community is relatively limited. The great genetic variability observed among ESBL-producing bacteria indicates polyclonal spread and high transference of ESBL genes between bacteria in the hospital environment. This information is of paramount importance for nosocomial infection control.
authors.affiliation: Medical Microbiology Laboratory, Universidade de Caxias do Sul, Rua Francisco Getulio Vargas 1130, Petropolis, Caxias do Sul, RS, Brazil. cwollhei@ucs.br
authors.forename: Claudia
authors.initials: C
authors.lastname: Wollheim
authors.forename: Ivani Maria F
authors.initials: IM
authors.lastname: Guerra
authors.forename: Vania D
authors.initials: VD
authors.lastname: Conte
authors.forename: Sheila P
authors.initials: SP
authors.lastname: Hoffman
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Schreiner
authors.forename: Ana Paula L
authors.initials: AP
authors.lastname: Delamare
authors.forename: Afonso L
authors.initials: AL
authors.lastname: Barth
authors.forename: Sérgio
authors.initials: S
authors.lastname: Echeverrigaray
authors.forename: Sérgio Olavo P da
authors.initials: SO
authors.lastname: Costa
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001938:Brazil / Q000453:epidemiology; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology*; D004269:DNA, Bacterial / Q000032:analysis; D052978:Disk Diffusion Antimicrobial Tests; D016521:Electrophoresis, Gel, Pulsed-Field; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology*; D005260:Female; D006801:Humans; D007709:Klebsiella / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases