title: Shiga toxin-producing Escherichia coli in drinking water supplies of north Paraná State, Brazil.
abstract: OBJECTIVE
  To determine the occurrence and characteristics of Shiga toxin-producing Escherichia coli (STEC) in drinking water supplies treated and untreated.
  
  
  RESULTS
  Drinking water samples (n = 1850) were collected from 41 municipalities in the north of Paraná State between February 2005 and January 2006. Escherichia coli isolates (n = 300) were recovered from water and investigated for the presence of virulence markers related to STEC by PCR. STEC isolates recovered were then characterized for both phenotypic and genotypic traits. A total of 12 isolates (11 from untreated water and one from treated water) were positive for stx, including five positive for both stx1 and stx2, two positive for stx1 and five positive for stx2. None of the STEC isolates contained eae, but other virulence genes were observed such as ehxA (100%), saa (100%), lpfAO113 (75%), iha (42%), subAB (25%) and cdtV (8%). Multidrug resistance was identified in 25% of the STEC isolates. The 12 STEC isolates belonged to seven distinct serotypes and pulsed-field gel electrophoresis typing revealed the presence of two clusters and two clones in this region.
  
  
  CONCLUSIONS
  Drinking water, especially from untreated water supplies, can be source of STEC strains potentially pathogenic for humans.
  
  
  CONCLUSIONS
  The investigation of the drinking water supplies for pathogenic E. coli, as STEC, may be useful to prevent waterborne outbreaks.
authors.affiliation: Department of Microbiology, Immunology and Parasitology - Escola Paulista de Medicina, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: K M S
authors.initials: KM
authors.lastname: Lascowski
authors.forename: B E C
authors.initials: BE
authors.lastname: Guth
authors.forename: F H
authors.initials: FH
authors.lastname: Martins
authors.forename: S P D
authors.initials: SP
authors.lastname: Rocha
authors.forename: K
authors.initials: K
authors.lastname: Irino
authors.forename: J S
authors.initials: JS
authors.lastname: Pelayo
mesh_terms: D000818:Animals; D001938:Brazil; D002522:Chlorocebus aethiops; D060766:Drinking Water / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field; D029968:Escherichia coli Proteins / Q000235:genetics; D005838:Genotype; D006460:Hemolysin Proteins / Q000235:genetics; D010641:Phenotype; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012703:Serotyping; D022622:Shiga Toxin 1 / Q000235:genetics; D022641:Shiga Toxin 2 / Q000235:genetics; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D014709:Vero Cells; D037521:Virulence Factors / Q000235:genetics; D014881:Water Supply
chemical_list: D060766:Drinking Water; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D037521:Virulence Factors