Antibiotic resistance of Helicobacter pylori in Nanjing, China: A cross-section study from 2018 to 2023

Abstract

Abstract Background The increasing prevalence of antibiotic resistance in cases of Helicobacter pylori (H. pylori) infection has emerged as a significant global issue. This study investigates the resistance situations, particularly the levofloxacin resistance pattern of H. pylori in Nanjing, China. Methods This research screened 4277 individuals diagnosed with H. pylori infection between April 2018 and May 2023. The phenotype and genotype resistance were evaluated using the Kirby-Bauer disk diffusion and ARMS-PCR method. Results The most recent primary resistance rates for metronidazole, clarithromycin, levofloxacin, amoxicillin, furazolidone, and tetracycline were recorded at 77.23% (2385/3088), 37.24% (1150/3088), 27.72% (856/3088), 0.52% (16/3088), 0.19% (6/3088), and 0.06% (2/3088), respectively. For the recent five years, we observed a notable upsurge in the rate of metronidazole resistance and a slight elevation of clarithromycin and levofloxacin resistance. The documented overall resistance rates to single-drug, dual-drug, triple-drug, and quadruple-drug regimens were 34.98%, 27.99%, 25.42%, and 0.21%, respectively. The prevalence of multidrug-resistant strains escalated, rising from 37.96% in 2018 to 66.22% in 2023. Strains from patients without levofloxacin eradication history showed significantly lower phenotypic (57.10%) and genotypic (65.57%) resistance rates compared to those with a history (94.74% and 88.73%, respectively). The prevailing gyrA mutations were primarily N87K (52.35%, 345/659), accompanied by D91N (13.96%, 92/659), and closely followed by D87G (10.77%, 71/659). An observed kappa value of 0.910 signifies strong concordance between ARMS-PCR and antibiotic sensitivity testing when identifying levofloxacin resistance. For gyrA mutations, the 91-amino acid mutants exhibit a higher likelihood of discrepancies between phenotypic and genotypic resistance than the 87-amino acid mutants. Conclusions The extent of antibiotic resistance within H. pylori remains substantial within the Nanjing region.Keeping track of regional information regarding antibiotic resistance in H. pylori is crucial for customizing individual treatment approaches. If levofloxacin proves ineffective in eradicating H. pylori during the initial treatment, its use in subsequent treatments is discouraged. The employment of levofloxacin resistance genotype testing can partially substitute conventional antibiotic sensitivity testing. Notably, predicting phenotypic resistance of levofloxacin through ARMS-PCR requires more attention to the mutation type of gyrA to improve prediction accuracy.