Genotyping Helicobacter pylori antibiotic resistance and virulence- associated genes in patients with gastric cancer in Wenzhou, China

Background and Study Aims: Helicobacter pylori infection affects approximately 50% of the global population and has become a serious health concern related to gastric cancer, gastritis, and peptic ulcers. This organism acquires drug resistance through gene mutations, and its increasing resistance to antibiotics has severely influenced the effectiveness of eradication efforts. Therefore, we designed this study to determine the prevalence of H. pylori virulence- (cagA and vacA) and antibiotic resistance - associated genotypes in patients with gastric cancer infected with H. pylori in Whenzhou, China. Patients and Methods: We used polymerase chain reaction (PCR) to confirm H. pylori in cancerous and paracancerous tissue specimens from 225 patients. Then we tested the prevalence of virulence- and antibiotic resistance - associated genotypes in H. pylori using a PCR-based DNA-sequencing assay. Results: We observed H. pylori DNA in 222 of the 225 patients and found the most prevalent virulenceassociated genotypes in cagA+ (97.75%) and vacAs1m1 (93.25%). Metronidazole resistance - associated gene mutation was G616A in rdxA; levofloxacin resistance - associated gene mutations were N87K, N87I, and D91G in gyrA; clarithromycin resistance - associated gene mutations were A2143G and A2142G in 23SrRNA; and amoxicillin resistance - associated gene mutation was T556S in pbp1. The most prevalent mutation related to antibiotic resistance was present in rdxA (97.30%), followed by gyrA (41.44%) and 23SrRNA (16.67%); the least prevalent was in pbp1 (2.25%). We observed single-gene mutations in 102 patients (45.95%) and found mutations in multiple genes (>2 genes) in 116 patients (52.25%). Conclusion: Patients with gastric cancer in Wenzhou, China, have high incidence infection caused by H. pylori with high-toxicity virulence genotypes. The frequency of gene mutations associated with metronidazole, levofloxacin, and clarithromycin resistances was high and that associated with amoxicillin resistance was relatively low. The mutation patterns were diverse, and the rates of multiple gene mutations were high. (c) 2021 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.

Automated summary

The study aimed to determine the prevalence of virulence- and antibiotic resistance-associated genotypes of H. pylori in gastric cancer patients in Wenzhou, China. High-toxicity virulence genotypes were prevalent in H. pylori infections in these patients, with frequent gene mutations related to metronidazole, levofloxacin, and clarithromycin resistances. Multiple gene mutations were also observed at a high rate.