Neogen Corporation has claimed it has developed the quickest enrichment and assay run-time test to detect Listeria.
The firm said it provides results after an assay run-time of 20 minutes and 16 hour enrichment time compared to competitive assays which can be one hour in assay-time and 24 hours in enrichment.
ANSR is an isothermal amplification reaction test method that exponentially amplifies the DNA of any bacteria present in samples to detectable levels.
Method of detection
Gerry Broski, senior marketing director of food safety at Neogen Corporation, told FoodProductionDaily.com the process starts with a sample from a food contact surface or product.
“The sample is placed in an enrichment broth and incubated to increase the presence of a food pathogen, in this case listeria.
“After about 16 hours, the enriched sample is then chemically lysed (split up) to release the RNA of the listeria (DNA for Salmonella).
“Using a second chemical, the RNA is converted to DNA which is then rapidly and exponentially amplified to a level which triggers a fluorescent reaction which is then detected by our instrument.
“The instrument measures the level of fluorescent signal and generates a result.”
Approval from the Association of Analytical Communities (AOAC) Institute is pending for the ANSR for Listeria test but the ANSR Salmonella test gained approval earlier in the year.
He said: “Pathogenic organisms are very tiny and have to be grown to a detectable level during the enrichment step.
“Basically, a culture sample is taken from a food contact surface or food product and incubated for a period of time in an enrichment medium."
Broski said the ANSR system is designed to detect listeria on environmental food-contact surfaces.
“We are currently testing the ANSR system for use on dairy products, turkey, cheeses, meats and fruits.
"The time savings that ANSR offers can reduce food-product hold times, which rely on these tests to ensure food safety."
The latest test is the ninth in less than six months and additional tests for the ANSR platform are currently in development.
“New products such as ANSR are a result of our investments in R&D, product development and our employees who are responding to the needs of the market.
“The ANSR system is the fastest isothermal test on the market, offering speed, cost effectiveness and simplicity. We have a stable and robust system which we will continue to expand with new assays.”