Classification of enterobacteria based on overall similarity.

Krieg, R. E. (Iowa State University, Ames), and W. R. Lockhart. Classification of enterobacteria based on overall similarity. J. Bacteriol. 92:1275-1280. 1966.-A numerical study was made of 53 organisms, representing 12 genera of the family Enterobacteriaceae and 4 members of the genus Aeromonas. A total of 105 features was determined for each culture. Matching coefficients were computed, and the organisms were sorted into phenetic groups by use of the "highest-link" criterion. The genera Enterobacter (Aerobacter), Escherichia, Citrobacter, Arizona, Shigella, and Salmonella formed a single, large cluster with little or no evidence of subdivisions into tribes or genera. Paracolobactrum and Klebsiella were joined to the large group as subclusters. Members of the genera Erwinia and Serratia formed separate, distinct clusters related to the large group at a lower level of similarity. At a still lower level were appended Aeromonas, Proteus, Providencia, and some individual species from other genera. These organisms were no more closely related to one another than to the larger group.