Listeria Monocytogenes

LITERATURE REVIEW

A. Listeria Monocytogenes

Listeria is under major food borne pathogens. Murray et al were credited with the discovery of small Gram-positive bacillus from blood of infected rabbits in 1924. Since it produces a typical monocytosis during illness in the diseased animal the organism was designated Bacterium monocytogenes. Pirie (1940) isolated an organism from gerbils which is very similar to that bacterium described by Murray et al and named it Listerella hepatolytica in honor of Lord Lister an English surgeon who is a discoverer of antisepsis (Doyle 1989). In 1939, it was discovered that the generic name Listerella had already been used for group of slime molds in 1906. This proposed name was changed by Pirie in 1940 from Listerella monocytogenes to Listeria monocytogenes. This name change was later approved in 1954 by the Judicial Commission on Bacteriological Nomenclature and Taxonomy (Ryser et al. 1991). In United States, in 1960s most of the listeriosis research was done based on animals by M. L. Gray and his associates (Doyle 1989). In 1985 eight species of listeria were recognized under Approved Lists of Bacterial Names. They are Listeria monocytogenes, L. ivanovii, L. inocua, L. welshimeri, L. denitrificans, L. murrayi, and L. grayi (Ryser et al. 1991). Although we can find these eight species of Listeria in the ninth edition of Bergey's Manual of Systematic Bacteriology, spp. L. grayi, and L. Murrayi are being consider for reclassification and placed in a newly created genus Murraya. L. denitrificance has been reclassified as Jonesia denitrificance. By observing the studies using DNA/DNA hybridization technology the degree of relatedness