Detection of point mutations on 23S rRNA of Helicobacter pylori and resistance to clarithromycin with PCR-RFLP in gastric biopsy specimens in Mersin, Turkey.

Background/aims: Helicobacter pylori infection has a high prevalence and is considered an important health problem in Turkey. Unfortunately, an effective treatment has not yet been found for the eradication of Helicobacter pylori infection, at least in our country. Standard therapies recommended for the eradication of Helicobacter pylori have failed in the province of Mersin, Turkey. The rate of eradication with the standard triple treatment was only 45% in the province of Mersin. It may be that Helicobacter pylori has become resistant to antibiotics. Therefore, we aimed to determine the rate of resistance to clarithromycin in the province of Mersin.

Methods: The study included 92 patients presenting with dyspepsia to the Gastroenterology Clinic of Mersin University Medical School and undergoing endoscopy. We obtained gastric biopsy specimens and investigated whether Helicobacter pylori was present and resistant to clarithromycin. We used polymerase chain reaction-restriction fragment length polymorphism to determine A2143G and A2144G mutations and resistance to clarithromycin.

Results: Out of 92 specimens, 37 (40.2%) had Helicobacter pylori DNA. Out of 37 specimens with Helicobacter pylori DNA, 15 (40.5%) had point mutations. Eleven specimens (29.7%) had mutations on nucleotide 2144 and 4 specimens (10.8%) had mutations on 2143.

Conclusions: Taking account of the failure of the treatment regimens used to eradicate Helicobacter pylori infection in the province of Mersin, the high rate of point mutations determined in this study was not surprising and the rate of resistance to clarithromycin was an important indicator for the failure in the eradication of Helicobacter pylori infection.