Neogen’s new Listeria Right Now™ test system can detect all species of Listeria, including the pathogenic L. monocytogenes, in under 60 minutes through their ribosomal RNA (rRNA). The system’s effectiveness has been validated by NSF International to detect low levels of Listeria in environmental samples with greater sensitivity and speed than any other method available. The test is also under review for AOAC Performance Tested certification to further validate its accuracy.
“The advanced technology in Listeria Right Now truly changes everything about testing the environment for Listeria. Contamination of Listeria in the environment can now be determined, and cleaned as necessary, before food production begins and the quality and safety of a food product is compromised,” said Ed Bradley, Neogen’s vice president of Food Safety. “The new test system enables food safety professionals to very quickly implement corrective actions, which could include improving sanitation efforts or processes. Using Listeria Right Now also means that companies no longer have to grow potentially dangerous cultures in their facilities during the testing process, nor store test cultures for potential follow-up testing.”
The innovative Listeria Right Now process starts with taking an environmental sample to capture any Listeria present. The entire swab sample is placed in a tube that contains a lysis buffer that breaks up any bacteria present, and releases its rRNA. If Listeria is in the sample, the test’s reagents will amplify thousands of copies of its rRNA — and make the Listeria easily detectable by Listeria Right Now.
In the validation study of Listeria Right Now comparing the test against the reference cultural method, NSF International confirmed the effectiveness of this new test. The evaluation determined that under the conditions employed in this study, the enrichment-free Listeria Right Now method is as sensitive as the enrichment-based culture reference method.
The system employs an isothermal, amplified nucleic acid-based reaction to target rRNA. Amplification occurs through a polymerization mechanism by a specific endonuclease. Detection occurs in real-time using a fluorescent, molecular beacon.
Ribosomal RNA is present in much greater numbers in Listeria cells than the traditional DNA target (~1000 – 10,000 copies per cell vs. 1 copy per cell for DNA). This can result in a 1,000 – 10,000 fold increase in target analyte concentration.
The isothermal reaction within the instrument produces a constant cycle of molecular replication producing analyte copies much more quickly than traditional PCR reactions which run through a series of heating and cooling cycles.