Oxford Listeria Agar Base is used with antimicrobics for the selective isolation of Listeria spp. in a laboratory setting. Oxford Listeria Agar Base is not intended for use in the diagnosis of disease or other conditions in humans. Listeria monocytogenes, described first in 1926 by Murray, Webb, and Swann, is an extensive problem in food industries. Epidemiological evidence from outbreaks of listeriosis has indicated that the principle route of transmission is via the consumption of foodstuffs contaminated with Listeria monocytogenes. Implicated vehicles of transmission included turkey frankfurters, coleslaw, pasteurized milk, Mexican style cheese, and pate. Listeria spp. are ubiquitous in nature, being present in a wide range of unprocessed foods as well as in soil, sewage and river water. Oxford Listeria Agar is prepared according to the formulation of Curtis et al. Listeria spp. grow over a pH range of 5.0 – 9.6 and survive in food products with pH levels outside these parameters.