172 страниц. 2012 год. LAP Lambert Academic Publishing Helicobacter pylori is a gram-negative bacterium that forms the etiology of chronic gastritis and peptic ulcer disease. Infection with H. pylori can be effectively treated by the combination of a proton pump inhibitor in addition Clarithromycin and amoxicillin. Emergence of Clarithromycin resistant strains of was not well studied in Sudan. Clarithromycin is a macrolide that binds to the 23S rRNA components of the bacterial ribosome. Resistant strains emerge due to failure of such binding because of modification of the target site by point mutations in the peptidyl transferase region of domain V of the 23S rRNA. H. pylori contain two copies of the 23S rRNA gene8. Several points mutations have been reported that are associated with macrolide resistance, but the most common is A-G transitions at position 2143 (A2143G).