A numerical taxonomic study of species ofVibrioisolated from the aquatic environment and birds in Kent, England

Abstract

A numerical taxonomic study was carried out to confirm the identity of strains of the family Vibrionaceae isolated during an ecological study. The 237 strains included 148 from the aquatic environment, 6 from estuarine birds, 1 from sheep feces and 61 control cultures. Duplicates of 21 of the strains were randomly selected and included to estimate test and operator error. Taxonomic resemblance was estimated on the basis of 148 characters using Euclidean distance. The taxonomic position of some strains was reevaluated using the pattern difference coefficient. Strains were clustered by 3 methods, all of which gave similar results. The estimated average probability of test error was 1.5%. Strains previously identified as V. anguillarum fell into 4 distinct phenons corresponding to V. anguillarum biovar I, V. anguillarum biovar II, V. diazotrophicus and strains pathogenic to oyster larvae. The latter group characteristically degraded xanthine and probably represents a new species. The phenon corresponding to V. cholerae included the type strain, strains of human origin, and strains isolated in the UK from birds and the aquatic environment. Some strains of V. cholerae were luminous. Other phenons were identified as V. metschnikovii, V. fluvialis and Aeromonas spp.