The Inappropriateness of Using Rifampicin E-Test to Predict Rifabutin Resistance in Helicobacter pylori. (8th December 2022)

• Record Type: Journal Article
• Authors: Yang, Tiankuo; Liu, Bowen; Zhou, Junpeng; Shen, Yalin; Song, Xiaona; Tang, Xiaoqiong; Benghezal, Mohammed; Marshall, Barry James; Tang, Hong; Li, Hong
• Is Part Of: Journal of infectious diseases. Volume 226(2022)Supplement 5
• Page Start: S479
• Page End: S485
• Publication Date: 2022-12-08
• Subjects: Helicobacter pylori -- cross-resistance -- rifabutin -- rifampicin; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiac417
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: The aim of this study was to evaluate the rifamycin cross-resistance in Helicobacter pylori, and whether the use of rifampicin E-test strips to screen H. pylori rifabutin resistance is appropriate. Methods: A total of 89 H. pylori isolates were included. Rifampicin minimum inhibitory concentrations (MICs) were obtained by E-test, while the MICs for rifapentine, rifaximin, and rifabutin were determined by agar dilution method. The rifamycin resistance rates based on different breakpoints were compared. Isolates with high-level rifampicin resistance were subjected to whole-genome sequencing. Results: A wide distribution of MICs (mostly in the range 0.125–8 mg/L) was observed for rifampicin, rifapentine, and rifaximin. Using MIC >1, ≥ 4, and > 4 mg/L as the breakpoints, resistance rates to rifampicin/rifapentine/rifaximin were 60.4%/48.3%/38.2%, 28.1%/25.8%/23.6%, and 15.7%/16.9%/7.9%, respectively. However, the rifabutin MICs of all the tested H. pylori isolates were extremely low (≤0.016 mg/L). Applying MIC ≥ 0.125 mg/L as the breakpoint, rifabutin resistance was nil. No mutation was found in the rpoB gene sequences of the 2 isolates with high-level rifampicin resistance. Conclusions: There is a lack of cross-resistance between rifabutin and other rifamycins in H. pylori . The use of rifampicin E-test to predict H. pylori rifabutin resistance is inappropriate.