Many attempts, based on biochemical properties, have been made to differentiate strains of the tribe Eschericheae-a biochemically heterogeneous collection of the Enterobacteriaceae-into genera. In the sixth edition of Bergey's Manual (Breed et al., 1948), these strains, if of animal origin, are classified into three genera: Escherichia, Aerobacter, and Klebsiella. The genus Aerobacter is subdiv...
