Taxonomic studies on Brochothrix, Erysipelothrix, Listeria and atypical lactobacilli.

One hundred and eighty-seven strains of listeriae, atypical lactobacilli, Brochothrix, Erysipelothrix and related Gram-positive bacteria were tested for 140 characters based on morphology, physiology and biochemistry. Computer analyses of the data resulted in the recovery of 20 phenons. Representative strains were examined for cytochrome content, cell wall, fatty acid and isoprenoid quinone composition and the G + C content of the DNA. The results indicate that the species Listeria monocytogenes, L. innocua and L. ivanovii are phenotypically very similar. L. grayi and L. murrayi are more distinct from these but are so similar to each other that L. murrayi should be regarded as a subspecies of L. grayi. Some of the atypical lactobacilli studied are members of the genus Brochothrix; the others probably represent four distinct species in a new genus.