title: [Frequency and pathotypes of diarrheagenic Escherichia coli in Peruvian children with and without diarrhea].
abstract: INTRODUCTION; Diarrheagenic E. coli (DEC) are a major cause of diarrhea in children in developing countries. However, they are not part of routine diagnosis in clinical laboratories.
  
  
  OBJECTIVE
  To determine the DEC prevalence in Peruvian children and to describe the genetic variability of these strains.
  
  
  METHODS
  A total of 8 003 E. coli strains previously isolated from eight different studies of diarrhea in children, mainly from peri-urban areas of Lima, were analyzed. Diagnosis of DEC was done with Multiplex real-time PCR using genes for each of the 6 DEC groups. Conventional PCR was performed for the detection of additional virulence genes.
  
  
  RESULTS
  Globally, the mean prevalence in diarrhea samples (n=4,243) was: enteroaggregative E. coli (EAEC) 9.9%, enteropathogenic E. coli (EPEC) 8.5%, enterotoxigenic E. coli (ETEC) 6.9%, diffusely adherent E. coli (DAEC) 4.8%, Shiga toxin-producing E. coli (STEC) 0.8% and enteroinvasive E. coli (EIEC) 0.6%. The relative frequency of each pathogen varies according to the age and the type of study. The main pathotypes in control samples (n=3,760) were EPEC (10.9%) and EAEC (10.4%). An important variability in the virulence genes frequency and molecular resistance mechanisms for each pathotype was found, without differences between diarrhea and control groups.
  
  
  CONCLUSIONS
  DEC are a major cause of diarrhea in Peruvian children. These pathogens are highly heterogeneous. Additional studies are required to determine the prevalence in rural areas of Peru and in severe diarrhea cases.
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú
authors.forename: Theresa J
authors.initials: TJ
authors.lastname: Ochoa
authors.forename: Erik H
authors.initials: EH
authors.lastname: Mercado
authors.forename: David
authors.initials: D
authors.lastname: Durand
authors.forename: Fulton P
authors.initials: FP
authors.lastname: Rivera
authors.forename: Susan
authors.initials: S
authors.lastname: Mosquito
authors.forename: Carmen
authors.initials: C
authors.lastname: Contreras
authors.forename: Maribel
authors.initials: M
authors.lastname: Riveros
authors.forename: Angela
authors.initials: A
authors.lastname: Lluque
authors.forename: Francesca
authors.initials: F
authors.lastname: Barletta
authors.forename: Ana
authors.initials: A
authors.lastname: Prada
authors.forename: Joaquim
authors.initials: J
authors.lastname: Ruiz
mesh_terms: D003967:Diarrhea / Q000382:microbiology*; D054308:Enteropathogenic Escherichia coli / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000150:complications*; D006801:Humans; D007223:Infant; D010568:Peru