Basic study in molecular noninvasive estimation of Clarithromycin resistant Helicobacter pylori: Set up of ASP-PCR in differentiation of infB, and PCR-sequencing to evaluate 23S rRNA, and rpl22 related mutations.

Designation of the local profile of Clarithromycin resistant (CAM-R) in Helicobacter pylori (H. pylori) positive patients with phenotypic testes consequently evaluation of probable agreement between resistance phenotypes to genotypes is the necessity of accessing rapid molecular noninvasive tests. So, we designed ASP-PCR and PCR-sequencing methods to evaluate infB (G160A), and 23S rRNA (A2142C/G, A2143C/G) and rpl22 (GTG deletion or TTCCATGTA insertion) nucleotide polymorphisms from stool of patients with symptoms of gastritis. Urea tubes were used to transport 96 gastric biopsies to the laboratory. Methods. Agar dilution method was performed to assess CAM-R strains. Besides the phenotypical identification, stool samples were collected and stored at -80° C. Molecular identity was characterized by amplification of 23S rRNA target gene. In evaluation of noninvasive genotypical molecular tests in detection of corresponded mutations, ASP-PCR was performed to isolate infB G160G wild-type strains and PCRsequencing in determining 23S rRNA and rpl22 polymorphisms. Results. Molecular isolation of H. pylori positive-patients was reported to be 34/54(62%). Among 35/96 (36%) phenotypically characterized H. pyloripositive infected patients,16/35(45%) were considered for CAM-R strains. Distribution of point mutations between resistant isolates have been revealed to be (1/16) for A2143C, (4/16) for infB G160A (PCR negative patients), (2/16) rpl22 for 3bp deletion, and (16/16) for rpl22 9bp insertion. Conclusion. We are honored to introduce rpl22-related point mutations as the potential marker in designing noninvasive molecular method in Clarithromycin resistant infected patients screening. [ABSTRACT FROM AUTHOR]