title: Prevalence and antibiotic resistance patterns of diarrheagenic Escherichia coli isolated from adolescents and adults in Hamedan, Western Iran.
abstract: OBJECTIVE
  Pathogenic strains of Escherichia coli are a common cause of acute infectious diarrhea. The aim of this study was to investigate the frequency, virulence markers and antibiotic resistance patterns of diarrheagenic E. coli (DEC) isolated from adolescents and adults in Hamadan, west of Iran.
  
  
  METHODS
  A total of 187 stool samples were collected from adults with acute diarrhea. Stool culture was performed by conventional methods for enteropathogenic bacteria. Virulence factor genes for DEC were detected by polymerase chain reaction. Antimicrobial susceptibility was tested using the disk diffusion method.
  
  
  RESULTS
  Among the 187 patients, 40 (21.4%) were positive for DEC. The most frequently identified DEC was enteropathogenic E. coli (47.5%), followed by enteroaggregative (20%), enterotoxigenic (17.5%) and shiga-toxin producing E. coli (15%). No isolates of enteroinvasive E. coli were detected. All STEC strains were stx+ / eaeA-. Out of the seven ETEC strains, five (71.4%) produced ST, one (14.3%) produced only LT and one (14.3%) of the isolates produced both ST and LT encoded by est and elt genes, respectively. Among the 40 DEC strains 27(67.5%) were multidrug resistant.
  
  
  CONCLUSIONS
  DEC contribute to the burden of diarrhea in adults in Hamadan. Enteropathogenic E. coli was the most commonly identified DEC strain in the region studied.
authors: Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamedan, Iran.
authors: Mohammad Yousef
authors: MY
authors: Alikhani
authors: Seyyed Hamid
authors: SH
authors: Hashemi
authors: Mohammad Mehdi
authors: MM
authors: Aslani
authors: Safar
authors: S
authors: Farajnia
keywords: Antimicrobial resistance; Diarrhea; Escherichia coli; Hamadan