June 28, 2022
Powerful new tool developed to combat cancer-causing bacteria in stomach
The bacteria Helicobacter pylori infects about half the population of the planet

Helicobacter pylori is one of the most common human pathogens. The bacteria infects the linings of the stomach, causing a number of diseases including gastritis, peptic ulcers and even stomach cancers. About half the population of the world is infected by Helicobacter pylori. The hardy bacteria can persist throughout the life of the patient if untreated. To treat an infection, it is necessary to identify an infection quickly, and select the right combination of sensitive antibiotics. Helicobacter pylori are slow growing and hard to cultivate, limiting the effecacy of the current tools available to healthcare workers to combat the bacteria. Researchers from China have developed a new medical instrument known as Clinical Antimicrobial Susceptibility Test Ramanometry for Helicobacter pylori (CAST-R-HP), that can act as a powerful new diagnostic tool for identifying infections by the bacteria.

The diagnostic tools needed for combating Helicobacter pylori have to be capable of profiling the genome-wide mutations that reveals the resistance mechanisms of the bacteria. One of the reasons why the bacteria is so hardy and persistent is its genetic variability that allows it to rapidly adapt to novel environments and conditions. The tests also have to be fast, reliable, and sensitive for pathogen identification tests, as well as antimicrobial susceptibility tests. The current approaches for detecting Helicobacter pylori and identifying the antibiotics suitable for eradication therapy are bacterial culture, and drug sensitivity testing based on gastric mucosal samples collected through endoscopy. Both of these approaches are painfully slow.

Senior author of the study, Zhang Jianzhong says, “The current culture-based antimicrobial susceptibility testing is too slow and requires at least a week of turnaround time.” The diagnostic tool developed by the team performs rapid pathogen identification, antimicrobial susceptibility tests based on metabolism inhibition, and single cell whole genome sequencing to uncover the antimicrobial resistance mechanisms. The approach has an accuracy of greater than 98 per cent, and directly works with a single cell resolution based on biopsy samples.

Senior author of the study, Xu Jian says, “The culture-independency, speed, high resolution and comprehensive information output suggest CAST-R-HP as a powerful tool for diagnosis and treatment of H. pylori infections, now at single-cell precision.” The researchers are looking at accelerating the process, for example, using a microfluidic chip to enhance the trace number of cells. The researchers hope to reduce the turn around time to less than 24 hours with such a chip. First author of the paper Liu Min says, “Our next step would be to fully assess the utility of the workflow for all the first-line and second-line antibiotics in use for the treatment of H. pylori infections.”

A paper describing the findings has been published in Clinical Chemistry.

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