title: Relationship between O serotype and virulent genes in Escherichia coli causing urinary tract infections.
abstract: BACKGROUND
  Escherichia coli are the most frequent pathogens in acute urinary infections. They are classified based on various types of O antigen. Escherichia coli strains that cause urinary tract infections possess several genes encoding urovirulent factors. To assay the relation of virulent factors of E coli in acute urinary infections, the serotypes and virulence factor genotypes were determined.
  
  
  METHODS
  We studied 96 E coli isolates from children with acute urinary infections. Four urovirulence determinants were analyzed by DNA colony hybridization, including the genes for type 1 fimbriae (pil), P fimbriae (pap), S fimbriae (sfa), hemolysin (hly), and cytotoxic necrotizing factor 1 (cnf1). O serotypes were also determined.
  
  
  RESULTS
  The most frequently found virulence factor-encoding gene in the E coli strains studied was the gene for type 1 fimbriae (27.4%). The prevalence of pap, sfa, hly, and cnf1 were higher in serotypes causing pyelonephritis than cystitis. The most common type of O antigen was O1 (12.2%). There was a significant correlation between serotype and genotype in uropathogenic E coli.
  
  
  CONCLUSIONS
  The high prevalence of O6 serotypes in children urinary tract infections and the high percentage of virulent genes in serotype O6 suggested a close relation between serotype and genotypes of uropathogen E coli.
authors: Division of Pediatric Nephrology, Department of Pediatrics, Jahrom University of Medical Sciences, Jahrom, Iran. ghoraishy@yahoo.com
authors: Fatemeh
authors: F
authors: Emamghoraishi
authors: Shohreh
authors: S
authors: Farshad
authors: Mehdi
authors: M
authors: Kalani
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis; D004927:Escherichia coli Infections / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007223:Infant; D008297:Male; D012494:Sampling Studies; D012703:Serotyping; D012720:Severity of Illness Index; D017678:Sex Distribution; D016482:Urinalysis; D014552:Urinary Tract Infections / Q000453:epidemiology* / Q000382:microbiology* / Q000652:urine; D056689:Uropathogenic Escherichia coli / Q000235:genetics* / Q000302:isolation & purification; D014774:Virulence
chemical_list: D004269:DNA, Bacterial