Classification and identification of rhodococci.

Ninety-nine representative strains of Rhodococcus were compared through 129 unit characters and the data examined using the simple matching, Jaccard and pattern coefficients. Clustering was achieved using the unweighted pair group method with arithmetic averages algorithm. The numerical classification was not affected by the statistics used or by test error, estimated at 1.95%. Sixteen multimembered and 23 single member clusters were defined by the simple matching coefficient at or above the 89% similarity level. The numerical phenetic data support the taxonomic integrity of all 13 validly described species of Rhodococcus, including Rhodococcus aichiensis. Rapid enzymic tests based upon fluorophores 7-amino-4-methylcoumarin and 4-methylumbelliferone provide valuable data for rhodococcal systematics.