No abstract

SUMMARY. The results of 91 characteristics selected from 165 tests performed on 127 clinical and other isolates of Pseudomonas aeruginosa were subjected to numerical analysis. Only one cluster, representing a single biotype of the species, was revealed at a similarity (S,) level of 95% and above. Ten melanogenic and six of the non-melanogenic isolates studied gave diverse atypical results in many of the tests; these strains appear to be aberrant forms of the species.