Objective Severe drug resistances to the first line antibiaotics used in eradication therapy have been observed in clinical isolates of Helicobacter pylori in China. The study conducted a multi-center drug susceptibility testing for minocycline, a second-generation semi-synthetic tetracycline, in clinical isolates of H. pylori, and set the epidemiological cutoff values （ECOFF） to provide scientific evidence for the selection of antibiotics for H. pylori eradication and the development of H. pylori infection prevention and control strategies.

Methods A total of 131 clinical isolates of H. pylori were obtained from Hubei, Yunnan, and Shaanxi provinces, representing the central, southwestern and northwestern regions of China. The minimum inhibitory concentration （MIC） range of minocycline to H. pylori was detected by using the standardized agar dilution method, and the ECOFF was calculated.

Results Most of the 131 clinical isolates of H. pylori were sensitive to minocycline, only a small amount of H. pylori strains showed low-level resistance, and the differences in drug resistanc were not significant among the strains from different regions. The research data showed that the ECOFF of minocycline for H. pylori was 0.5 mg/L.

Conclusion H. pylori is generally sensitive to minocycline.in China The ECOFF value of minocycline is low, and the use of minocycline in clinical eradication therapy is expected to have good effect.