Helicobacter pylori 23S rRNA gene mutations associated with clarithromycin resistance in chronic gastritis in Vietnam

Abstract

Introduction: Data about the prevalence of the A2142C, A2142G, and A2143G mutations in 23S rRNA gene is still limited. The aim of this study was to determine the prevalence of these mutations in 23S rRNA gene of H. pylori vietnamese strains. Methodology: One hundred and sixty-nine patients with H. pylori-positive chronic gastritis were examined. H. pylori was detected by rapid urease test and Polymerase chain reaction (PCR). Total DNA was extracted from gastric biopsy specimens. A2142C, A2142G, and A2143G mutations were detected by DNA sequencing and PCR-restriction fragment length polymorphism (PCR-RFLP). Results: A2143G mutation was detected in 36.1% of samples, A2142G mutation in 3.6%, while A2142C mutation was not found in any case. The mixture of wild-type and mutation strains was found in 50% of specimens with A2142G, in 23% of specimens with A2143G mutation. There was no association of 23S rRNA gene point mutations with gender or age. However, an association between the heterogeneity of mutation and age was evidenced, with mean age of the group of pure A2143G higher than the group of wild-type/A2143G mixture, and rate of the wildtype/A2143G mixture higher in patients under 40 years of age. Conclusion: A2143G mutation was prominent, while A2142C mutation was not found in the 23S rRNA gene. PCR-RFLP has revealed a reliable assay allowing a rapid and cost-effective detection of clarithromycin-resistant strains. This is useful in countries as Vietnam with high prevalence of clarithromycin-resistance before choosing optimal therapy for H. pylori eradication.

Molecular Mechanisms of Antibiotic Resistance and Novel Treatment Strategies for Helicobacter pylori Infections

“…However, the number of sequenced samples (25) was relatively small. The screening of 169 patients positive for chronic gastritis in Vietnam, using PCR-RFLP, found the A2143G mutation in 36.1% of samples and the A2142G mutation in 3.6%; however, it failed to detect the A2142C mutation [ 29 ].…”

Vietnam Association of Gastroenterology (VNAGE) consensus on the management of Helicobacter pylori infection

“…Comments: The results of clinical trials conducted during the last 5 years in Vietnam showed that the primary resistance rates of clarithromycin and metronidazole were very high, up to 34.1 and 69.4%, respectively ( 4 , 38 ). Recent data also show that the resistance rates of amoxicillin and levofloxacin tend to increase significantly ( 39 , 40 ).…”

Antibiotic resistance and heteroresistance in Helicobacter pylori isolates from symptomatic Vietnamese children: A prospective multicenter study

“…The coexistence of multiple H. pylori strains in the same patient may be the result of simultaneous colonization, which has been described in many studies, 45,46 including in the Vietnamese population. 47…”

“…The vacA genotyping results also demonstrated that 27.9% of patients had multiple vacA genotypes in the same gastric biopsy ( s1/m1m2 , s1s2/m2 , and s2/m1m2 ), suggesting multiple strains infections. The coexistence of multiple H. pylori strains in the same patient may be the result of simultaneous colonization, which has been described in many studies, 45,46 including in the Vietnamese population 47 . In addition, PCR‐based methods are highly sensitive but fail to differentiate between alive and dead bacteria, which can lead to false positive results.…”