Listeria detection system receives approval

Food manufacturers worried about listeria will now be able to use the detection system created by DuPont Qualicon after it was approved for use last week.

The company announced that its BAX system for detecting Listeria has been certified as performance tested by the AOAC Research Institute of Gaithersburg, Maryland

The validation study compared the BAX system - a DNA-based technology - to the standard culture method used by the USDA food safety and inspection service, which requires a 48-hour dual enrichment and manual plating.

AOAC-RI found that the new system performed as well as the culture method for detecting listeria species on environmental surfaces such as plastic, ceramic, rubber, concrete, wood, cast iron and air filter material.

Moreover, the system combines a single enrichment step with shorter incubation times, so that test results should be available 30-33 hours after sampling.

"Labs that need third-party endorsement have been waiting for this approval," said Kevin Huttman, president of DuPont Qualicon. "Now they can start saving time and money."

A USDA report published in December suggested that an interim final rule designed to reduce the incidence of Listeria monocytogenes (LM) in ready-to-eat (RTE) meat and poultry products was working.

The report showed that the overall safety of these products has improved because manufacturers have strengthened their control procedures, increased testing and taken additional steps to eliminate the pathogen.

"If progress continues at the current rate, we should achieve the Healthy People 2010 goal of lowering the incidence of listeriosis to 0.25 cases per 100,000 people," said agriculture under secretary for food safety Dr Elsa Murano

The interim final rule on controlling LM was based upon a risk assessment for LM in ready-to-eat meat and poultry products. It requires all establishments producing RTE products that are exposed to the environment after cooking to consider LM a hazard likely to occur, develop written programs to control it and to verify the effectiveness of those programs through testing.

Establishments must share testing data and plant generated information relevant to their controls with FSIS. Plants that rely on sanitation measures alone to control LM receive the greatest level of scrutiny from the agency.

The report found that following the implementation of the rule, many plants have made improvements to address the problem of LM. In some cases, antimicrobial ingredients have been added to product formulations to inhibit the growth of LM and post-processing treatment has been installed to eliminate the pathogen.

In addition, the report found that plants have either initiated or greatly increased their testing for Listeria or Listeria-like organisms on plant surfaces that come in contact with products after cooking. These testing data are available to FSIS inspection personnel as a result of the interim final rule and are used to determine the effectiveness of sanitation and other control measures.