A visual diagnostic detection of Helicobacter pylori and the gastric carcinoma-related virulence genes (cagA and vacA) by a fluorescent loop-mediated isothermal amplification (LAMP)

Talanta. 2023 May 1:256:124260. doi: 10.1016/j.talanta.2023.124260. Epub 2023 Jan 10.

Abstract

Helicobacter pylori (H. pylori) infection has increasingly been a serious problem worldwide. The H. pylori infection can result in a series of stomach diseases including gastric carcinoma. There are two specific virulence genes (cagA and vacA) of H. pylori that are closely related to the occurrence of gastric cancer, and the common molecular detection methods (PCR, qPCR) are not suitable for high-screening test due to the requirement of expensive instruments and well-trained personals. Herein, we develop a rapid visual assay based on loop-mediated isothermal amplification (LAMP) for detecting H. pylori and its major virulence genes (cagA, vacAs1 and vacAm1) to guide clinical treatment for H. pylori infection. In this research, a fluorescent LAMP assay was established by optimizing the indicator of MnCl2-Calcein, so that the resulted color and fluorescence changes could be utilized to perform the visual detection for H. pylori and its virulence genes with high sensitivity (10-3 ng/μL). The proposed LAMP assay is simple, fast (30 min) and capable in providing more sensitive results than traditional methods in the test of 46 clinical biopsy samples. By detecting the three virulence genes together, we can profile the infection risk of the patients, and discuss the correlation among the genes. Moreover, the method could be used to diagnose virulently infected individuals and benefit the eradication of H. pylori in early warning for gastric cancer.

Keywords: Helicobacter pylori; Loop-mediated isothermal amplification; Virulence genes; Visual detection.

MeSH terms

  • Antigens, Bacterial / genetics
  • Bacterial Proteins / genetics
  • Carcinoma*
  • Gastritis* / genetics
  • Gastritis* / pathology
  • Genotype
  • Helicobacter Infections* / diagnosis
  • Helicobacter Infections* / epidemiology
  • Helicobacter Infections* / pathology
  • Helicobacter pylori* / genetics
  • Humans
  • Molecular Diagnostic Techniques
  • Nucleic Acid Amplification Techniques
  • Stomach Neoplasms* / diagnosis
  • Stomach Neoplasms* / pathology
  • Virulence / genetics

Substances

  • Bacterial Proteins
  • Antigens, Bacterial

Supplementary concepts

  • LAMP assay