title: Distribution of Integrons and Gene Cassettes Among Uropathogenic and Diarrheagenic Escherichia coli Isolates in Iran.
abstract: Integrons are considered to play a significant role in the evolution and spread of antimicrobial resistance genes. A total of 200 uropathogenic (UPEC) and diarrheagenic Escherichia coli (DEC) isolates from outpatients were investigated for antimicrobial susceptibility and the presence of class 1, 2, and 3 integron-associated integrase (intI) genes and gene cassettes. Conjugal transfer and Southern hybridization were performed to determine the genetic localization of class 1 integrons. One hundred ninety-two (96%) isolates were resistant to one or more antimicrobial agents. Antimicrobial resistance among DEC isolates was higher compared with the UPEC. Integrons were highly prevalent in both pathotypes (92.5%). Comparison of integrons among UPEC and DEC showed that DEC isolates harbored integrases (94% for intI1, 8% for intI2) with a slightly higher frequency than in UPEC isolates (87% for intI1, 7% for intI2) (p>0.05). Dihydrofolate reductase (dfrA) and aminoglycoside adenyl transferase (aad) gene cassettes were found most frequently in intI1-positive isolates. All isolates carried their class 1 integrons on conjugative plasmids. These results indicate that class 1 integrons are widespread among E. coli isolates. Therefore, appropriate surveillance and control measures are essential to prevent the further spread of integron-producing isolates.
authors: 1 Department of Microbiology, Zanjan University of Medical Sciences , Zanjan, Iran .
authors: Habib
authors: H
authors: Zeighami
authors: 1 Department of Microbiology, Zanjan University of Medical Sciences , Zanjan, Iran .
authors: Fakhri
authors: F
authors: Haghi
authors: 2 Department of Microbiology, Zanjan Islamic Azad University , Zanjan, Iran .
authors: Neda
authors: N
authors: Masumian
authors: 1 Department of Microbiology, Zanjan University of Medical Sciences , Zanjan, Iran .
authors: Fatemeh
authors: F
authors: Hemmati
authors: 1 Department of Microbiology, Zanjan University of Medical Sciences , Zanjan, Iran .
authors: Ali
authors: A
authors: Samei
authors: 1 Department of Microbiology, Zanjan University of Medical Sciences , Zanjan, Iran .
authors: Ghazal
authors: G
authors: Naderi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015139:Blotting, Southern; D003227:Conjugation, Genetic / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D003967:Diarrhea / Q000382:microbiology; D004352:Drug Resistance, Microbial / Q000235:genetics; D054308:Enteropathogenic Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D006801:Humans; D019426:Integrases / Q000235:genetics; D032023:Integrons / Q000235:genetics*; D007492:Iran / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D014552:Urinary Tract Infections / Q000453:epidemiology / Q000382:microbiology*
chemical_list: C405495:AADA4 protein, E coli; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D019426:Integrases; C115006:integron integrase IntI1