title: Identification of a Novel Cassette Array in Integronbearing Helicobacter Pylori Strains Isolated from Iranian Patients.
abstract: Helicobacter pylori as the second most common cause of gastric cancer in the world infects approximately half of the developed countries population and 80% of the population living in developing countries. Integrons as genetic reservoirs play major roles in dissemination of antimicrobial resistance genes. To the best of our knowledge, this is the first study to report carriage of class 1 and 2 integrons and associated gene cassettes in H. pylori isolates from Iran. This crosssectional study was conducted in Tehran among 110 patients with H. pylori infection. Antimicrobial susceptibility testing (AST) for H. pylori strains were assessed by the micro broth dilution method. Class 1 and 2 integrons were detected using PCR. In order to determine gene cassettes, amplified fragments were subjected to DNA sequencing of both amplicon strands. The prevalence of resistance to clarithromycin, metronidazole, clarithromycin, tetracycline, amoxicillin, rifampin, and levofloxacin were 68.2% (n=75), 25.5% (n=28), 24.5% (n=27), 19.1% (n=21), 18.2% (n=20) and 16.4% (n=18), respectively. Frequency of multidrug resistance among H. pylori isolates was 12.7%. Class 2 integron was detected in 50 (45.5%) and class 1 integron in 10 (9.1%) H. pylori isolates. The most predominant gene cassette arrays in class 2 integron bearing H. pylori were included sateraaadA1, dfrA1sat2aadA1, blaoxa2 and, aadB whereas common gene cassette arrays in class 1 integron were aadBaadA1cmlA6, aacA4, blaoxa2, and catB3. The high frequency of class 2 integron and multidrug resistance in the present study should be considered as a warning for clinicians that continuous surveillance is necessary to prevent the further spread of resistant isolates.
authors: Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran Email : gudarzim@yahoo.com.
authors: Mehdi
authors: M
authors: Goudarzi
authors: Sima Sadat
authors: SS
authors: Seyedjavadi
authors: Maryam
authors: M
authors: Fazeli
authors: Maryam
authors: M
authors: Roshani
authors: Mehdi
authors: M
authors: Azad
authors: Mohsen
authors: M
authors: Heidary
authors: Masoumeh
authors: M
authors: Navidinia
authors: Hossein
authors: H
authors: Goudarzi
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy / Q000382:microbiology*; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D032023:Integrons / Q000235:genetics*; D007492:Iran; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial