Title Phenotypic and Genotypic Analysis of Clarithromycin-Resistant Helicobacter pylori from Bogotá D.C., Colombia
Author Alba A. Trespalacios1*, William Otero2, Jorge E. Caminos3, Marcela M. Mercado1, Jenny Ávila1, Liliana E. Rosero1, Azucena Arévalo1, Raúl A. Poutou-Piñales4, and David Y. Graham5,6
Address 1Infectious Diseases Group, Microbiology Department, Science Faculty, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia, 2Gastroenterology Unit. Clínica Fundadores, Bogotá, D.C., - Colombia and Universidad Nacional de Colombia, Bogotá, D.C., - Colombia, 3Biochemistry Unit, Universidad Nacional de Colombia, Bogotá, D.C., Colombia, 4Molecular Biotechnology Laboratory, Environment and Industrial Biotechnology Group (GBAI), Microbiology Department, Science Faculty, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia, 5Department of Medicine, Michael E. DeBakey Veterans Affairs Medical Center Houston, TX, USA, 6Baylor College of Medicine, Houston, TX, USA
Bibliography Journal of Microbiology, 51(4),448-452, 2013,
DOI 10.1007/s12275-013-2465-6
Key Words Helicobacter pylori, clarithromycin resistance, 23S rRNA mutations
Abstract Resistance of Helicobacter pylori to clarithromycin is the most common cause of treatment failure in patients with H. pylori infections. This study describes the MICs and the presence of 23S rRNA mutations of H. pylori isolates from Bogotá, D.C., Colombia. H. pylori were isolated from gastric biopsies from patients with functional dyspepsia. Clarithromycin susceptibility was investigated by agar dilution and strains were considered resistant if the MIC was ≥1 μg/ml. DNA sequences of the 23S rRNA gene of strains resistant and sensitive to clarithromycin were determined to identify specific point mutations. Clarithromycin resistance was present in 13.6% of patients by agar dilution. The A2143G, A2142G and A2142C mutations were found in 90.5, 7.1, and 2.4% of H. pylori strains with resistance genotype.The resistant phenotype was associated with 23S rRNA resistance genotype in 85.7% of isolates. The point mutations in 23S rRNA were well correlated with MICs values for clarithromycin.