Quantitative PCR of string‐test collected gastric material: A feasible approach to detect Helicobacter pylori and its resistance against clarithromycin and levofloxacin for susceptibility‐guided therapy

Abstract

AbstractBackgroundAs the reduced eradication rate of Helicobacter pylori (H. pylori), we introduced string‐test and quantitative PCR (qPCR) for susceptibility‐guided therapy innovatively. The practicality of the string test was evaluated.MethodsIt was an open‐label, non‐randomized, parallel, single‐center study, in which subjects tested by 13C‐ urea breath test (UBT) and string‐qPCR were enrolled. Based on the results of string‐qPCR, we calculated clarithromycin and levofloxacin resistance rates and gave 13C‐UBT positive patients 14 days susceptibility‐guided bismuth quadruple therapy. In the empirical therapy group, we retrospectively analyzed the treatment results of 13C‐UBT positive patients also treated with bismuth quadruple at Shenzhen Luohu People's Hospital from January 2021 to May 2022. The eradication rate was compared between susceptibility‐guided therapy and empirical therapy groups.ResultsThe diagnosis of H. pylori infection using the string‐qPCR had an overall concordance rate of 95.9% with the 13C‐UBT results. Based on the results of string‐qPCR, the clarithromycin and levofloxacin resistance rates were 26.1% and 31.8%, respectively. The patients who were given 14 days susceptibility‐guided bismuth‐based quadruple therapy achieved a high H. pylori eradication rate of 91.8%. Retrospective analysis of patient treatment data from January 2021 to May 2022 available in the hospital database revealed an overall success rate of 82.3% for those who received empirical bismuth‐based quadruple therapies, which is marginally significantly lower than that of the string‐qPCR susceptibility‐guided group (p = 0.084).ConclusionThe high treatment success rate of 91.8% indicates that the string‐qPCR test is a valuable and feasible approach for clinical practice to help improve H. pylori treatment success rate.