Evaluation of a Molecular Mosprie Assay for Detection of Helicobacter pylori and Resistance to Clarithromycin and Levofloxacin

Abstract

Background Helicobacter pylori eradication regimens should be guided by antimicrobial susceptibility testing. The objective of this study was to evaluate the molecular-based Mosprie assay for detecting H. pylori resistance to clarithromycin and levofloxacin using gastric biopsies. Methods A total of 185 culture-positive frozen gastric biopsies were included for Mosprie assay and also for 23S rRNA and gyrA gene sequencing. The susceptibility results by the Mosprie assay were compared with the E-test results retrospectively retrieved. The discordant results were analyzed by sequencing of the 23S rRNA and gyrA genes. Results Susceptibility concordance between the Mosprie assay and E-test for clarithromycin and levofloxacin was 97.30% (180/185) and 88.11% (163/185), respectively. The full agreement between clarithromycin genotypes by Mosprie assay and the 23S rRNA sequencing results was observed in the 5 samples with discordant Mosprie assay and E-test results. However, for levofloxacin, of the 16 discordant samples with resistant phenotype but a susceptible genotype by Mosprie assay, 6 were found to have levofloxacin resistance-related gyrA gene mutations. Conclusions The rapid and reliable Mosprie assay can be recommended for H. pylori susceptibility testing of clarithromycin and levofloxacin on gastric biopsies. Future technical improvements are needed in detecting levofloxacin resistance-associated gene mutations.

Empirical versus tailored therapy based on genotypic resistance detection for Helicobacter pylori eradication: a systematic review and meta-analysis

“…Although it is generally believed that the detection of antibiotic resistance by molecular method and E-test method is highly consistent, some samples have been reported to be phenotypically resistant but genotypically sensitive, suggesting that some rare mutations associated with phenotypic resistance may be missed by molecular method. 12 A recent study demonstrated that the molecular testing-guided therapy was comparable to susceptibility testing-guided therapy in first-line treatment and non-inferior to susceptibility testing-guided therapy in third-line treatment, supporting the use of molecular testing-guided therapy for H. pylori eradication. 13 But the evidence for the use of genotypic resistance-guided therapy in eradicating H. pylori infection compared to conventional treatment regimens remains to be evaluated.…”