To characterize antimicrobial resistance patterns of Helicobacter pylori (H.pylori) in the Xizang region through parallel molecular and conventional culture-based susceptibility testing, and to assess the clinical concordance between these methods.

A cohort of 100 consecutive patients with active H.pylori infection confirmed by gastroscopy was prospectively enrolled between September 2023 and June 2025. Detailed data on prior H.pylori treatment histories, antibiotic exposure, and allergies were documented. Gastric mucosal biopsies from the antrum and body were split for: (1) PCR detection of clarithromycin (23S rRNA) and fluoroquinolone (gyrA) resistance mutations; and (2) culture and Kirby-Bauer disk diffusion susceptibility testing against eight antibiotics. Resistance rates of H. pylori to different antibiotics were analyzed. Using the culture method as the gold standard, the diagnostic value of the PCR method for detecting clarithromycin and levofloxacin resistance was explored.

A total of 100 patients were enrolled (92 with no prior H.pylori treatment history and 8 with prior H.pylori treatment). The positivity rates for H.pylori detected by culture and PCR methods showed a statistically significant difference (81.0% vs 99.0%, P<0.01). Phenotypic resistance rates were as follows: metronidazole 66.7% (54/81), levofloxacin 39.5%(32/81), clarithromycin 22.2% (18/81), amoxicillin 4.9% (4/81), gentamicin 3.7% (3/81), and furazolidone/tetracycline/rifampicin each at 1.2%(1/81). Multidrug resistance patterns were observed: 40.7% (33/81) single-drug resistance (mainly metronidazole), 24.7% (20/81) double-drug resistance (mainly levofloxacin+metronidazole), and 12.4% (10/81) triple-drug resistance (levofloxacin+clarithromycin+metronidazole). PCR identified clarithromycin and levofloxacin resistance in 38.4% (38/99) and 41.4% (41/99) of cases, respectively, with 28.3% (28/99) exhibiting dual resistance. The Kappa value for detecting clarithromycin resistance between PCR and culture methods was 0.62 (95% confidence interval [CI]: 0.43~0.80, P＜0.001), and for levofloxacin resistance, it was 0.72 (95%CI: 0.57~0.86, P＜0.001).

This study reveal that the three antibiotics with the highest resistance rates to H. pylori in Xizang are metronidazole, levofloxacin, and clarithromycin, while amoxicillin and gentamicin show intermediate resistance rates, and furazolidone, tetracycline, and rifampin exhibit lower resistance rates. The PCR method demonstrated a significantly higher positive rate for H. pylori compared to the culture method, and both methods showed good consistency in detecting resistance to clarithromycin and levofloxacin.