Abstract
OBJECTIVE: To characterize antibiotic resistance, virulence genotypes and phylogenetic lineages of Helicobacter pylori (H. pylori) isolates from Eastern China and identify resistance/virulence-associated genetic variants. METHODS: Whole-genome sequencing (WGS) and phenotypic antimicrobial susceptibility testing (AST) for 6 antibiotics were performed on 141 H. pylori isolates from Hangzhou, China. Genetic analysis (resistance mutations, virulence genotyping, phylogenetic tree) and the assessment of antibiotic resistance related phenotype-genotype concordance were conducted. RESULTS: Metronidazole resistance was highest (85.1%), followed by levofloxacin (57.4%), clarithromycin (53.9%) and amoxicillin (21.3%); tetracycline and furazolidone resistance was low at 2.8% and 0.7%, respectively. Key resistance mutations included 23S rRNA A2143G (clarithromycin, 92.91% phenotype-genotype concordance), gyrA N87K (levofloxacin, 89.13% concordance) and pbp1A 1785_1786insAGC (amoxicillin, 83.69% concordance). Dominant virulence genotypes: cagA ABD (86.26%), vacA s1-type (100%, 58.02% s1m2, 41.22% s1m1), htrA 171S (61.07%). 95.4% of strains clustered in hpEastAsia lineage; 3.8% in hpEurope, 0.76% in hpAsia2. CONCLUSION: H. pylori isolate in Eastern China show high resistance to common antibiotics and dominant high-virulence genotypes. WGS identifies key resistance markers, aiding targeted H. pylori treatment.