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Clustering of antibiotic resistant and susceptible Iranian Helicobacter pylori strains using RAPD-PCR profiling

Abstract number: R2372

Mohammadi M., Doroud D., Saberi Kashani S., Douraghi M., Mohajerani N., Esmaeili M., Bababeik M., Oghalaie A., Talebkhan Y.

Objectives:Helicobacter pylori (Hp) infects the majority of the adult population in developing countries including Iran and is associated with gastrointestinal diseases such as gastritis, peptic ulcer disease (PUD) and gastric cancer. Antibiotic resistance is a key factor in the failure of Hp eradication therapy. Hence characterisation of susceptible and resistant strains and identification of their clonal population is critical. This study conceived to provide information on the diversity of Metronidazole and Clarithromycin resistant Hp strains in Iran.

Methods: The susceptibility testing of 50 Hp isolates were performed and interpreted according to the guidelines from the Clinical and Laboratory Standards. Two set of primers were designed to detect point mutations in the 23S rRNA gene responsible for clarithromycin resistance and RFLP was done to reveal point mutations via digestion of PCR products with BsaI, MboII. Another set of primers were used for detection of rdxA gene deletion responsible for metronidazole resistance. All of the strains were typed by RAPD-PCR.

Results: Approximately 17.6% and 59.4% of strains were resistant to clarithromycin and metronidazole respectively. One (3.3%) strain was resistant to both antibiotics. RAPD-PCR revealed amplified fragment sizes ranging from 2kb to 0.17kb. With 80% similarity 18 clonal populations were identified based on RAPD profiling. Most (80%) of the strains of cluster 5 were resistant to metronidazole whereas 78% of the strains in cluster 6 were susceptible to both antibiotics.

Conclusion: These results indicate that clinical Helicobacter pylori strains in terms of antibiotic resistance are highly diverse. It seems the characteristics of the resistant and susceptible strains can be predicted by clustering of strains using RAPD-PCR profiling.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Barcelona, Spain
Presentation type:
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