https://orcid.org/0000-0002-9995-5522
I read Rokkas and Graham’s [Citation1] review article with great interest, suggesting that the current universal availability of susceptibility testing for Helicobacter pylori and performing therapy to susceptibility-based optimized therapies portend a worldwide change in the approach and odds of successful therapy for H. pylori. Particularly, the use of stool-based susceptibility testing eliminates the need for gastric biopsies, thus promoting efficient optimization when endoscopic examination is difficult, especially when managing pediatric H. pylori infection. Rokkas and Graham suggested that culture, molecular testing (polymerase chain reaction [PCR]), or next-generation sequencing methods are useful in drug susceptibility testing for H. pylori. However, further research is needed to investigate the drug sensitivity testing methods for H. pylori.
Although Rokkas and Graham reported that sensitivity testing methods for H. pylori are available worldwide, I believe that this is not the case. Culture-based drug susceptibility testing is time-consuming and limited in the facilities where it can be performed. Additionally, the fact that it takes several days to receive the results of the testing makes it impossible to start eradication treatment promptly, which becomes a burden for medical physicians and patients. Due to the current lack of testing method standardization or consensus on the antibiotic resistance breakpoints, culturing for H. pylori drug susceptibility testing is seldom implemented [Citation2].
Attempts to test for H. pylori clarithromycin (CAM) resistance using molecular methods have been reported [Citation3,Citation4], because many cases of H. pylori eradication therapy failure largely depend on the presence or absence of CAM resistance [Citation5]. However, these methods have been difficult to implement in the clinical setting because they require individual clinicians to use a machine that is large and high-priced, which limits their accessibility in medical establishments where it can be set up. Additionally, the method requires special technical skills. Considering this, we developed a new reagent for evaluating H. pylori genes and CAM-resistant mutations using stool samples, developed as a dedicated reagent for the Smart Gene™ point-of-care testing kit [Citation6,Citation7]. Smart Gene™ (Mizuho Medy Co., Ltd., Tosu-City, Saga, Japan) was developed based on the concept of point-of-care testing, which can mechanically perform nucleic acid extraction and amplification and the detection of the target genes. It is a small, lightweight, and inexpensive gene detection device ($5,000 per unit) and is purchased once and can be used continuously at an additional cost for reagents only. The reagents used in Smart Gene™ for H. pylori are also inexpensive, costing ~$30 per sample. To our knowledge, this is the world’s first reagent for point-of-care testing that is capable of rapidly detecting H. pylori genes and CAM-resistant mutations. The assay combines PCR and the quenching probe method, which simultaneously detects H. pylori genes and CAM-resistant mutations in ~30–50 min with a single test. Moreover, the test time is far shorter than that of conventional methods. Using our developed equipment and reagents, even at the clinic level, H. pylori CAM resistance can b e measured without requiring special skills, which can be a powerful method for tailored therapy for H. pylori eradication, as mentioned by Rokkas and Graham.
In conclusion, to improve the efficacy of tailored therapy for H. pylori eradication, it is essential to further develop simple and economical molecular methods that can test the drug susceptibility of H. pylori.
Declaration of interest
T Kakiuchi developed a reagent for Smart GeneTM, which is affiliated with Mizuho Medy Co., Ltd. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
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References
- Rokkas T, Graham DY. How widespread and convenient H. pylori susceptibility testing will result in pharmacological opportunities. Expert Rev Gastroenterol Hepatol. 2023;17(1):1–7.
- Tang X, Shen Y, Hu R, et al. Re-assessment of the disk diffusion technique for routine antimicrobial susceptibility testing for Helicobacter pylori. Helicobacter. 2020;25(4):e12703.
- Xiong LJ, Tong Y, Wang Z, et al. Detection of clarithromycin-resistant Helicobacter pylori by stool PCR in children: a comprehensive review of literature. Helicobacter. 2013;18(2):89–101.
- Redondo JJ, Keller PM, Zbinden R, et al. A novel RT-PCR for the detection of Helicobacter pylori and identification of clarithromycin resistance mediated by mutations in the 23S rRNA gene. Diagn Microbiol Infect Dis. 2018;90(1):1–6.
- Kato S, Konno M, Maisawa S, et al. Results of triple eradication therapy in Japanese children: a retrospective multicenter study. J Gastroenterol. 2004;39(9):838–843.
- Kakiuchi T, Hashiguchi K, Imamura I, et al. Assessment of a novel method to detect clarithromycin-resistant Helicobacter pylori using a stool antigen test reagent. BMC Gastroenterol. 2020;20(1):397.
- Kakiuchi T, Okuda M, Matsuo M, et al. Smart Gene™ as an effective non-invasive point-of-care test to detect Helicobacter pylori clarithromycin-resistant mutation. J Gastroenterol Hepatol. 2022;37(9):1719–1725.