Molecular assessment of clarithromycin resistant Helicobacter pylori strains using rapid and accurate PCR-RFLP method in gastric specimens in Iran
Currently, a seven-day, triple-drug regimen has been recommended as one of the first-line therapies for Helicobacter pylori management in which clarithromycin is a key component. Development of clarithromycin resistance leads to the long term assessment of the efficacy of clarithromycin in the triple-drug regimen. The aim of this study was to rapidly and directly assess clarithromycin resistance point mutations on gastric biopsy specimens by using PCR-RFLP method. Biopsy samples were obtained over a 6-months period of 2009, from 200 dyspeptic patients referred to Shahrekord University of Medical Sciences, Iran. Initially, rapid urease test was performed and then DNA was isolated from each tissue and used for molecular analysis such as PCR (for H. pylori diagnostic) and PCR-RFLP (for Cla resistance determination). RUT and PCR results showed that 164 (82%) of the patients were H. pylori-positive. Resistance was evaluated in 164 samples by using enzymes BsaI and MboII. Thirty nine (39) (23/78%) clarithromycin-resistant strains were detected which were identified as 15 (9.15%) A2143G, 15 (9.15%) A2142G and 9 (5.49%) mix strains. The results showed that PCR-RFLP method had a high accuracy to detect A2142G and A2143G mutations associated with resistance to clarithromycin in the minimum possible time.
Key words: Helicobacter pylori, clarithromycin resistance, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP).