Document Type : Original Article (s)
Authors
1
Associate Professor, Department of Microbiology, Jahrom Branch, Islamic Azad University, Jahrom, Iran.
2
Department of Microbiology, Jahrom Branch, Young Researcher's Clube, Islamic Azad University, Jahrom, Iran.
3
Assistant Professor, Biotechnology Research Center, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
4
Assistant Professor, Biotechnology Research Center, Islamic Azad University, Shahrekord Branch, Shahrekord, Iran
Abstract
Background: Helicobacter pylori is a fastidious microorganism and therefore standard phenotypic susceptibility tests can take at least 10-14 days. Molecular based diagnostic assays offer an alternative approach to obtain susceptibilities to antibiotics and detection of point mutations with greater accuracy. The aim of this study was the assessment of Clarithromycin resistance and its point mutations by using real-time PCR assay.Methods: This cross-sectional descriptive study was performed on 200 gastric biopsy specimens obtained from patients undergoing upper gastrointestinal endoscopy at Hajar hospital in Shahrekord. Initially Helicobacter pylori were identified by rapid urease test (RUT) and polymerase chain reaction (PCR). Then clarithromycin resistance and its point mutations were evaluated by using specific probes and real-time PCR technique.Finding: Of total samples, 164 (82%) were Helicobacter pylori positive. Overall, a clarithromycin susceptible strains were detected in 105 (64.02%) patients and resistance strains were detected in 59 (35.98%) which were identified as 4 (2.44%) A 2144G, 26 (15.85%) A2143G, 15 (9.15%) A2143C, and 20 (12.19%) A2142G point mutations. Genotype of 5 (8.47%) strains was not detected. Purely resistant strains were detected in 38 (23.17%), while heteroresistant were found in the remaining 16 cases (9.76%).Conclusion: Results showed that real-time PCR assay has high accuracy to simultaneously identify Helicobacter pylori and clarithromycin resistance types directly in gastric biopsy specimens in short time.
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