Clarithromycin resistance stability in Helicobacter pylori: influence of the MIC and type of mutation in the 23S rRNA

• Published in: Journal of antimicrobial chemotherapy Vol. 46; no. 4; pp. 613 - 616
• Main Authors: Alarcón, Teresa, Domingo, Diego, Prieto, Nuria, López-Brea, Manuel
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01.10.2000; Oxford Publishing Limited (England)
• Subjects: Anti-Bacterial Agents - pharmacology; Antibacterial agents; Antibiotics. Antiinfectious agents. Antiparasitic agents; Bacteriology; Biological and medical sciences; Cells, Cultured; clarithromycin; Clarithromycin - pharmacology; Culture Media; Drug Resistance, Microbial - genetics; Fundamental and applied biological sciences. Psychology; Genetics; Helicobacter pylori; Helicobacter pylori - drug effects; Helicobacter pylori - genetics; Humans; Medical sciences; Microbial Sensitivity Tests - methods; Microbiology; Mutation - drug effects; Mutation - genetics; Pharmacology. Drug treatments; RNA, Ribosomal, 23S - drug effects; RNA, Ribosomal, 23S - genetics; Clarithromycin; Spirillales; Spirillaceae; 23S-RNA; In vitro; Macrolide; Resistance; Antibiotic; Helicobacter pylori; Ribosomal RNA; Minimum inhibitory concentration; Microorganism culture; Bacteria; Mutation; Antibacterial agent
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/46.4.613

Thirty clarithromycin-resistant Helicobacter pylori strains (MIC range 8–64 mg/L) were subcultured in a drug-free medium and the MIC was determined every five passages to detect in vitro stability of resistance. Three out of the 30 (10%) lost their resistance after 10, 13 or 18 subcultures (MIC decrease from 8 to 0.008, from 16 to 0.064 and from 32 to 0.016 mg/L). The effect of four macrolides at subinhibitory concentrations on the development of resistance was studied in H. pylori NCTC 11638 and TIGR 26695. A change in the MIC was observed only when NCTC11638 was exposed to 0.5 × MIC of erythromycin for 20 days.