Assessment of a novel method to detect clarithromycin-resistant Helicobacter pylori using a stool antigen test reagent.

Background: The resistance rate of Helicobacter pylori to clarithromycin (CAM) is high among infected children in Japan. Therefore, a new method for detecting CAM-resistant H. pylori using a minimally invasive technique is strongly desired. We aimed to investigate the clinical usefulness of our newly developed nested polymerase chain reaction-quenching probe (Nested PCR-QP) method using stool specimens.

Methods: We first evaluated our method using a residual solution of the H. pylori stool antigen test for adolescents. Then, we evaluated our method using culture testing for adults.

Results: Among 57 middle school students with H. pylori, the Nested PCR-QP test results of 53 (90.3%) were able to be analyzed. A total of 28 students had CAM resistance mutations. We found a genetic mutation in 28 students and no mutation in 23 students, and these results were consistent with those of PCR-direct sequencing. In the 23 adults who were diagnosed with H. pylori infection using the rapid urease test and culture testing, we were able to use Nested PCR-QP for analyzing 21 adults who tested positive in the stool H. pylori antigen test. The results obtained for all 21 adults were consistent with those obtained via the drug susceptibility test.

Conclusions: Our novel method could be useful for non-invasively detecting CAM resistance mutations in H. pylori. This may help select a drug to reduce eradication failure rates against H. pylori. Trial registration This study was registered with the University Hospital Medical Information Network Clinical Trials Registry (no. UMIN000030632, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000034977 ) on 29 December 2017.