title: [Adhesion patterns in diffusely adherent Escherichia coli (DAEC) strains isolated from children with and without diarrhea].
abstract: BACKGROUND
  Diffusely adherent E. coli (DAEC) is the sixth recognized group of diarrheagenic E. coli. However, its association with diarrhea remains controversial. Variability in the adherence patterns of clinical strains is unknown.
  
  
  OBJECTIVE
  To compare the adherence patterns between strains isolated from children with and without diarrhea.
  
  
  METHODS
  A total of 31 DAEC strains were analyzed, 25 from children with diarrhea and 6 from asymptomatic (control) children, isolated from a cohort study of children under one year of age in the southern districts of Lima. DAEC were identified by PCR (daaD gene). The pattern and adherence score in HEp-2 cell culture were evaluated, Actin polimerization was determined by fluorescence actin staining (FAS) and motility was evaluated by conventional microbiology methods.
  
  
  RESULTS
  Diffuse adherence pattern was found in 88% of diarrhea samples and in the total of control strains. The number of bacteria adhered per cell was significantly lower in diarrhea samples (p<0.05). However, actin polymerization was greater in diarrhea samples (60% vs. 17%). Motility test was positive in 60% of the diarrhea samples and in all control samples.
  
  
  CONCLUSIONS
  Our findings suggest a difference between adherence patterns, actin polymerization and motility between DAEC strains corresponding to diarrhea and control groups. The significance of these results must be confirmed with a bigger number of strains and determining the presence of virulence genes in the strains.
authors.affiliation: Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Perú
authors.forename: Maribel
authors.initials: M
authors.lastname: Riveros
authors.forename: Francesca
authors.initials: F
authors.lastname: Barletta
authors.forename: Martín
authors.initials: M
authors.lastname: Cabello
authors.forename: David
authors.initials: D
authors.lastname: Durand
authors.forename: Erik H
authors.initials: EH
authors.lastname: Mercado
authors.forename: Carmen
authors.initials: C
authors.lastname: Contreras
authors.forename: Fulton P
authors.initials: FP
authors.lastname: Rivera
authors.forename: Susan
authors.initials: S
authors.lastname: Mosquito
authors.forename: Angela
authors.initials: A
authors.lastname: Lluque
authors.forename: Theresa J
authors.initials: TJ
authors.lastname: Ochoa
mesh_terms: D001422:Bacterial Adhesion; D003967:Diarrhea / Q000382:microbiology*; D004926:Escherichia coli / Q000302:isolation & purification / Q000502:physiology*; D006801:Humans; D007223:Infant