The testing of four enrichment media for optimal detection of Listeria spp.

Abstract

By Sara Keith, Biology

Advisor: Daniel Buchholz

Presentation ID: PM_C10

Abstract: Listeriosis is an infection from Listeria spp. which can lead to many symptoms that include: headaches, confusion, loss of balance or convulsions. This is especially problematic in the immunocompromised, infants and pregnant women which can lead to miscarriage or premature labor. Listeria spp. contamination has been a rising problem in produce and historically is found in unpasteurized milk and milk products. The ability to detect this bacterium is important in food safety. In this study, 4 different proprietary enrichment media formulations were compared to determine the optimal growth conditions for Listeria spp. to be tested on multiple rapid method platforms. Depending on the food or product type, all samples were also confirmed via the USDA or the FDA reference methods. The results for this study concluded that one proprietary enrichment media formulation was able to provide optimal nutrients and selective reagents to suppress the growth of competing bacteria but provide optimal growth conditions for the target organism to be detected on an ELISA immunoassay. Other proprietary enrichment media formulations analyzed was not able to promote the growth for the target organism to a high enough level to produce the same quality of results in the same assay. The results generated will enable laboratories to produce results that are accurately and reliable to ensure the food safety requirements are being met and safe for the consumer.