Current status of Helicobacter pylori resistance to clarithromycin and levofloxacin in Vietnam: Results from molecular analysis of gastric biopsy specimens.

ABSTRACT

OBJECTIVES: The management of Helicobacter pylori in Vietnam is becoming progressively more difficult due to increasing antibiotic resistance, particularly to clarithromycin (CLR) and levofloxaxin (LVX). In Vietnam, the selection of an H. pylori eradication regimen is predominantly based on empirical evidence. However, molecular analysis aimed at identifying H. pylori antibiotic-resistant genotypes is a promising method in antibiotic susceptibility testing. In this study, we aimed to determine the rates of genotypic H. pylori resistance to CLR and LVX by using DNA strip technology in Vietnam. METHODS: We performed DNA-strip technology-based testing on 112 patients with H. pylori-positive gastroduodenal diseases to detect 23S rRNA and gyrA mutations. RESULTS: Helicobacter pylori genotypic resistance to CLR and LVX was evident in 81.3% and 53.6% of the patients, respectively, and dual resistance was observed in 48.2%. The 23S rRNA A2142G and A2143G mutations accounted for 1.8% and 79.5% of cases, respectively. The gyrA N87K, D91N, D91G, and D91Y mutations were present in 37.5%, 11.6%, 5.4%, and 5.4% of patients, respectively. All four gyrA mutations were observed in both the naïve and failure patients. We further found an association between the 23S rRNA A2143G mutation and a history of CLR use as well as between the gyrA N87K mutation and a history of LVX use. CONCLUSIONS: We found a very high prevalence of H. pylori resistance to CLR and LVX and dual resistance to these antibiotics in Vietnam. The application of molecular assays is feasible and may improve the management of H. pylori infection in Vietnam.