CHARACTERIZATION OF LISTERIA BY STANDARDIZED CELLULAR PROTEIN ELECTROPHORETIC PATTERNS

Seventy-five strains of the six currently recognized Listeria species were characterized using cellular protein profiles. With the exception of L. grayi (including strains designated as L. murrayi), which showe d significant differences from all other species, all exhibited a high degree of homogeneity with only few visible differences between their protein patterns. Numerical analysis of normalized and standardized p rotein profiles, however resulted in the grouping of strains received as L. seeligeri, L. welshimeri and L. ivanovii into distinct species c lusters. With a few exceptions, strains of L. innocua and L. monocytog enes were also found in separate clusters. Highly standardized cellula r protein profiles corroborates the recent taxonomy of Listeria and ca n be used as additional tool for species (group) differentiation.