Luminex Submits ARIES MRSA Assay for FDA Clearance

Luminex Corporation announced that the company submitted the ARIES® MRSA Assay to the U.S. Food and Drug Administration (FDA) for clearance on Friday, June 28, 2019. The assay is a real-time, quantitative polymerase chain reaction (qPCR)-based, in vitro diagnostic test for the direct detection of methicillin-resistant Staphylococcus aureus (MRSA) DNA from nasal swabs in patients at risk for nasal colonization.

"This submission demonstrates our continued dedication to expanding the menu of clinically relevant and high-value tests that support patient care throughout the world on our sample to answer platforms," said Homi Shamir, President and CEO of Luminex. "Our VERIGENE® II GI Flex and RSP Flex submissions, as well as the commercialization of our new SENSIPLEX™ instrument, remain on track with our previously communicated timelines."

According to the U.S. Centers for Disease Control and Prevention, in 2016, there was approximately one case of MRSA for every 30 people in the U.S. This works out to around 10 million cases of MRSA in the U.S. each year.1,2 Rapid molecular tests for organisms such as MRSA have the potential to aid physicians in reigning in the spread of antimicrobial resistance and the associated negative outcomes for both patients and healthcare facilities by reducing the unnecessary use of antimicrobial therapies, thus allowing for more effective patient management.

The Luminex ARIES® System is a sample to answer, real-time system designed to increase laboratory efficiency, ensure result accuracy, and fit seamlessly into the modern laboratory. The system already offers six FDA and seven CE-IVD cleared assays, as well as the ability to run laboratory developed tests. "This assay will add another foundational test to the ARIES® System, increasing its value for customers and patients," said Shamir.

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Chemiluminescence Probes for the Rapid and Sensitive Detection of Salmonella and Listeria

Salmonella and listeria are among the most widely distributed and deadliest causes of foodborne infections. Their rapid and reliable detection on food and industrial food processing equipment is very important. In the journal Angewandte Chemie, scientists have introduced a new, ultrasensitive, chemiluminescence-based method for the direct detection of Salmonella and Listeria monocytogenes. Because of the simplicity and sensitivity, this test is significantly faster than conventional methods and can be carried out in the field.

It is estimated that about a million people per year are infected with salmonella infections in the USA alone. Of these, 380 die. Infections with listeria can also often be fatal. Current testing methods usually require the growth of bacterial cultures in a containment laboratory. A conclusive result based on standard diagnostic techniques generally takes two to six days.

Researchers working with Urs Spitz and Doron Shabat at the University of Tel Aviv, Nemis Technologies AG (Zurich, Switzerland), Zurich University of Applied Sciences, and Biosynth AG (Staad, Switzerland) have now introduced a new and efficient method for the ultrasensitive and significantly faster detection of Salmonella and Listeria. The method is based on chemiluminescence -- the emission of light resulting from a chemical process. The simplicity of the tests allows for both enrichment of the bacteria and their detection in a test tube, with no further sample preparation, so no containment laboratory is required. The chemiluminescence probes have proven to be about 600 times more sensitive than conventional fluorescence probes.

The success of this technique is due to two specially developed probe molecules made by combining a luminescent substance (a phenoxy-dioxetane) with a "trigger." In this form the probe does not light up. The trigger is tailored to the bacteria to be detected: it is recognized by a specific enzyme produced by the pathogen -- a special esterase in the case of Salmonella and a special phospholipase C for Listeria -- that splits it from the luminescent part. This initiates a chemical reaction that causes the luminescent molecule to split off more pieces. The energy released by the reaction is emitted in the form of a very intense green glow. Tests with various bacteria demonstrated that the probe tailored to Listeria test only reacts to Listeria monocytogenes, not to other, non-pathogenic, strains of listeria. The intensity of the glow can be used to quantify the concentration of bacteria. The tests are so sensitive that, for example, a count of ten salmonella can be detected within six hours of enrichment. Even dried bacteria can be swabbed from surfaces and detected.

The researchers are confident that their new method can be used more broadly to develop specific chemiluminescence probes for other bacteria.

Reference

Michal Roth-Konforti, Ori Green, Mario Hupfeld, Lars Fieseler, Nadine Heinrich, Julian Ihssen, Raffael Vorberg, Lukas Wick, Urs Spitz, Doron Shabat. Ultrasensitive Detection of Salmonella and Listeria monocytogenes by Small-Molecule Chemiluminescence Probes. Angewandte Chemie International Edition, 2019; DOI: 10.1002/anie.201904719

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