Novel PCR Test Detects H. Pylori Drug Resistance

Helicobacter pylori is a Group 1 carcinogen that is responsible for approximately 89% of lower stomach gastric cancer cases.

Helicobacter pylori infection affects nearly half of the world's population and is associated with peptic ulcer, gastric ulcers, mucosa-associated lymphoid tissue lymphoma and gastric cancer. In developing countries, the prevalence of infection is as high as 90%.

The gold standard diagnostic procedure for H. pylori detection is the use of a gastric fluid culture and antimicrobial susceptibility testing which typically takes a minimum of five days to obtain a definitive result. Other more rapid methods have low sensitivity for the detection of H. pylori including the helicobacter-urease assay from gastric biopsies, antigen testing from stool or breath tests. Scientists have evaluated a molecular based diagnostic test for H. pylori called the Hpylori-Q Assay (Autogenomics, Inc., Carlsbad, CA, USA), an automated multiplexed film-based microarray assay that can simultaneously detect H. pylori and its resistance to clarithromycin from human biopsy samples in a clinic setting.

A total of 100 gastric biopsies were performed to isolate genomic DNA (50 H. Pylori positive and 50 H. Pylori negative), from specimens previously evaluated with the M-PCR assay. The 100 DNA samples were retested with the Autogenomics Hpylori-Q assay. The results showed that, the Hpylori-Q assay detected 48 out of the 50 H. pylori positive DNA specimens (96% sensitivity) and identified the entire 50 negative DNA as negative for H. pylori (100% specificity). In addition, 17 out of the 50 positive specimens were tested as clarithromycin resistant (34%), while nine had an A2142G point mutation, another nine DNA carried A2143G point mutation and one carried both A2142G, and A2143G mutations. The limit of detection for H. pylori was 22 copies per test for the Hpylori-Q assay.

The INFINITI H. pylori Assay can be performed on AutoGenomics' INFINITI Plus and INFINITI High Throughput System (HTS) and is designed to meet the needs of small and large volume laboratories. Fareed Kureshy, MBA, President and CEO of AutoGenomics, said, “With the addition of the INFINITI H. pylori Assay, we now have 26 CE-marked molecular diagnostic tests and two CE-marked instruments to serve the international market in the areas of personalized medicine, oncology, women's health and infectious diseases.” The study was presented at the 69th AACC Annual Scientific Meeting and Clinical Expo held July 30 to August 3, 2017, in San Diego, CA, USA.

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