Prevalence Of Clarithromycin Resistance Of Helicobacter Pylori In A Population With A History Of Administration Of The Antibiotics

Background Infection of Helicobacter pylori (H. pylori) is a recognized cause of chronic active gastritis and peptic ulcer diseases. It is also an aetiological factor of stomach cancer. The prevalence of H, pylori infection may reach 60% or more in China. In recent years, resistance to clarithromycin is increasing that leads to more and more failure of H. pylori eradication by the antibiotics.Aim 1) To setup a rapid PCR-based assay to detect H. pylori infection and clarithromycin resistance simultaneously. 2) To investigate the prevalence and pattern of clarithromycin resistance among about 900 subjects with or without a history of administration of the antibiotics. 3) To evaluate formation of resistance and the long-term maintenance of eradication of H, pylori by clarithromycin.Mothod Gastric juice samples (n=876) were gathered from subjects in a high risk area of stomach cancer enrolled in an intervention study. H. pylori infection and the mutations associated with clarithromycin resistance were determined by PCR of 23S rDNA and restriction fragment length polymorphism (RFLP), respectively. The short- and long-term maintenance of eradication by clarithromycin were evaluated also by combining with the results of ¹³C-urea breath (¹³C-UBT) test and enzyme-linked immunosorbent assay (ELISA).Results1) Using the results (both positive or negative) of ¹³C-UBT and ELISA as golden standard, the sensitivity of PCR assay of 23S rDNA in the fixed fasting gastric juice was 83.3%; specificity, 75.1%; and Youden's index, 0.58.2) 23S rDNA of H. pylori was detected in 57.5% (504/876) of gastric juice samples, A2143G point mutation of 23S rDNA was observed in 70 of 504 PCR...