INTRODUCTION: The aim of this study was to characterize the mutations types present in the 23S rRNA gene related to H. pylori clarithromycin-resistance strains in Spain and evaluate a novel PCR-RFLP method for detection of the most frequent point mutation in our population. METHODS: Gastric biopsies were obtained by endoscopy from patients with gastric symptoms. H. pylori was cultured according to standard microbiological procedures and clarithromycin resistance was determined by E-test. DNA extraction was performed by NucliSens platform with the NucliSens magnetic extraction reagents (bioMérieux) according to the manufacturer instructions. Analyses for point mutations in 23S rRNA gene strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using BsaI enzyme to detect restriction sites that correspond to the mutation (A2143G). RESULTS: We found 42 out of 118 (35.6%) strains resistant to clarithromycin by E-test. E-test results were confirmed for the presence of point mutation in 34 (88.1%) of these strains. Mutation A2143G was found in 85.3% of the strains. Analyses with the restriction enzyme BsaI was able to confirm the presence of A2143G mutation. There were 8 H. pylori strains resistant to clarithromycin by E-test but without any point mutation in the 23 rRNA gene. CONCLUSIONS: We conclude that PCR-RFLP is a reliable method to detect clarithromycin-resistance H. pylori strains in countries with a high prevalence of clarithromycin-resistance as Spain. It may be useful before choosing regimens of H. pylori eradication.
INTRODUCTION: The aim of this study was to characterize the mutations types present in the 23S rRNA gene related to H. pyloriclarithromycin-resistance strains in Spain and evaluate a novel PCR-RFLP method for detection of the most frequent point mutation in our population. METHODS: Gastric biopsies were obtained by endoscopy from patients with gastric symptoms. H. pylori was cultured according to standard microbiological procedures and clarithromycin resistance was determined by E-test. DNA extraction was performed by NucliSens platform with the NucliSens magnetic extraction reagents (bioMérieux) according to the manufacturer instructions. Analyses for point mutations in 23S rRNA gene strains were performed by sequence analysis of amplified polymerase chain reaction products. Restriction fragment length polymorphism was performed using BsaI enzyme to detect restriction sites that correspond to the mutation (A2143G). RESULTS: We found 42 out of 118 (35.6%) strains resistant to clarithromycin by E-test. E-test results were confirmed for the presence of point mutation in 34 (88.1%) of these strains. Mutation A2143G was found in 85.3% of the strains. Analyses with the restriction enzyme BsaI was able to confirm the presence of A2143G mutation. There were 8 H. pylori strains resistant to clarithromycin by E-test but without any point mutation in the 23 rRNA gene. CONCLUSIONS: We conclude that PCR-RFLP is a reliable method to detect clarithromycin-resistance H. pylori strains in countries with a high prevalence of clarithromycin-resistance as Spain. It may be useful before choosing regimens of H. pylori eradication.
Authors: J Versalovic; M S Osato; K Spakovsky; M P Dore; R Reddy; G G Stone; D Shortridge; R K Flamm; S K Tanaka; D Y Graham Journal: J Antimicrob Chemother Date: 1997-08 Impact factor: 5.790
Authors: S Koletzko; F Richy; P Bontems; J Crone; N Kalach; M L Monteiro; F Gottrand; D Celinska-Cedro; E Roma-Giannikou; G Orderda; S Kolacek; P Urruzuno; M J Martínez-Gómez; T Casswall; M Ashorn; H Bodanszky; F Mégraud Journal: Gut Date: 2006-04-07 Impact factor: 23.059
Authors: Teresa Alarcón; Alba E Vega; Diego Domingo; Maria Josefa Martínez; Manuel López-Brea Journal: J Clin Microbiol Date: 2003-01 Impact factor: 5.948