Listeria spp.

Background:  Listeria spp. can be used as an indicator organism that pathogenic Listeria monocytogenes, which can cause serious illness in persons with heightened immune susceptibility, is present.

Listeria spp. in environmental samples collected from production facilities, especially if ready-to-eat products are being produced.

Traditional assays for Listeria spp. require 40-48 hours of incubation whereas this assay, in conjunction with proprietary media, has been AOAC approved for 24 hours of incubation for environmental swab samples, and 26 to 28 hours for product samples.

The BAX System uses DNA-based technology to provide next-day results that are reliable and reproducible, allowing food producers and processors to quickly and accurately release safe products to the market.



Turn Around Time

Sample Required

Type of Test

Reportable Units

Detection Limit

AOAC 081401 BAX Real-Time PCR

BAX System

1-2 Business Days

25g to 375 g or Swab

Qualitative Pathogen Analyses

Negative or Positive per 25g or 375g or swab analyzed

One Viable Cell per 25g or 375g or swab analyzed

This is a Quantitative analysis, this test will detect if only one Listeria spp. cell is present, therefore resulting in a Negative or Positive result.  This assay does not tell you how much of the pathogen is present.

Standard sample sizes are one swab, 25g, 65g or 375g.  Representative sample portions are collected from sample submitted, mixed with highly selective enrichment media and incubated for 24 to 48 hours.  After incubation, cells from the sample enrichment are broken open to expose their DNA, which, if the target Listeria spp. DNA is present, will be copied thousands of times, allowing for detection via the BAX Real Time PCR Listeria spp. assay.

Customers desiring cultural confirmation of positive pathogen enrichments must request so within 24 hours of MBL reporting the positive pathogen result.