Numerical Taxonomy of Vibrios Isolated from Aquatic Environments

Abstract

A total of 443 strains of Vibrio, many of which were isolated from estuaries in the United States, were studied with numerical taxonomy to determine relationships among those species known to be pathogenic for humans, e.g., V. cholerae, V. mimicus, V. fluvialis, V. parahaemolyticus, and V. vulnificus, as well as among strains not identifiable from the minimum diagnostic characteristics likely to be used in many clinical laboratories. Similarity coefficients were calculated on the basis of 133 characters, using Euclidean distance. Most of the strains clustered in phena along with reference strans. Several new, as yet undescribed phena containing strains isolated from diverse geographic locations were detected. Deficiencies in current schemes for identification of V. vulnificus and V. parahaemolyticus were observed, and the definitions of these species were extended by using information obtained in this study.