title: Identification and characterization of class 1 integrons among atypical enteropathogenic Escherichia coli isolated from children under 5 years of age.
abstract: OBJECTIVE
  The therapeutic options for diseases caused by Escherichia coli are limited. In this study we investigated the presence of virulence factors among Enteropathogenic Escherichia coli (EPEC) strains and their antibiotic resistance patterns. The isolates were also checked for the presence of class1 integrons and gene cassettes.
  
  
  METHODS
  This study included 70 EPEC strains isolated from children. Antimicrobial resistance patterns were determined using diffusion methods. The broth microdilution methods was used to determine the minimum inhibitory concentration. PCR was used to detect eaeA, bfpA genes. The 5' and 3' conserved sequences (CSs) of class 1 integrons and intI gene were amplified to investigate the presence of integrons and gene cassettes.
  
  
  RESULTS
  Antimicrobial susceptibility testing showed that 4 (5.7%), 3 (4.2%), and 2 (2.8 %) isolates were resistant to ampicillin, trimethoprim-sulfamethoxazole, and ceftazidime, respectively. Resistance rates to ciprofloxacin and aztreonam were 1.4%. Thirteen (18.5%) isolates showed resistance to tetracycline, and 4 (5.7%) were kanamycin resistant. Class I integron detected in 22 (31.4%) isolates. All the gene cassettes found in class I integrons corresponded to different variants of dfr and aadA genes.
  
  
  CONCLUSIONS
  Prevalence of class I integrons in EPEC strains was high. Presence of aadA and dfr gene cassettes in integrons represents high distribution of resistance determinants in EPEC strains.
authors: Special Disease Center, Shiraz University of Medical Science, Shiraz, Iran.
authors: Farzad
authors: F
authors: Shahcheraghi
authors: Department of Bacteriology & Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors: Fatemeh
authors: F
authors: Rahmati Ghezelgeh
authors: Department of Bacteriology & Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors: Saman
authors: S
authors: Nobari
authors: Department of Bacteriology & Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors: Elham
authors: E
authors: Torabi
authors: Department of Bacteriology & Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors: Seyed Fazlollah
authors: SF
authors: Mousavi
authors: Department of Bacteriology & Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors: Mohammad Mehdi
authors: MM
authors: Aslani
authors: Department of Bacteriology & Microbiology Research Center, Pasteur Institute of Iran, Tehran, Iran.
authors: Fereshteh
authors: F
authors: Shahcheraghi
keywords: Children; Class I integrons; Enteropathogenic Escherichia coli