Buffered Listeria Enrichment Broth

Buffered Listeria Enrichment Broth is used for selective enrichment of Listeria spp and 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 public health and food industries. Evidence from outbreaks of listeriosis has indicated that the principle route of transmission is via consumption of foodstuffs contaminated with Listeria monocytogenes. Implicated vehicles of transmission include 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.

Buffered Listeria Enrichment Broth, a modification of the formula by Lovett et al., was developed after subsequent work concluded that enrichment properties can be improved by increasing the buffering capacity of the medium with the addition of Disodium Phosphate. Listeria spp. grow over a pH range of 5.0 - 9.6, and survive in food products with pH levels outside these parameters. Listeria spp. are microaerophilic, Gram-positive, asporogenous, non-encapsulated, non-branching, short, motile rods. Motility is pronounced at 20°C. Identification of Listeria is based on successful isolation of the organism, biochemical characterization, and serological confirmation.