Identification of Vibrio spp. with a set of dichotomous keys


Anicet R. Blanch, Department of Microbiology, University of Barcelona, Diagonal 645, 08028 Barcelona, Spain. E-mail:


Aims:  To define a binary biochemical key for the identification of all recognized Vibrio spp.

Methods and Results:  A matrix of phenotypical results was developed based on the previous taxonomical studies and the first description manuscripts. A unification of results from various sources was also performed to integrate different taxonomical studies within the same data matrix. Established criteria for selecting the optimal set of tests yielded the highest discrimination, as well as the lowest number of tests. An initial identification key was defined using arginine dihydrolase, lysine decarboxylase and ornithine decarboxylase tests, as well as defining eight different clusters. This key leads each cluster to a secondary key for species identification. Most of Vibrio spp. presented an identification threshold of 100%.

Conclusions:  A new set of biochemical keys has been determined provides a scheme for the rapid identification of clinical and environmental species of Vibrio. No more than 14 are needed for even the most complicated identifications. This newly defined set of keys updates and improves similar findings published in previous studies.

Significance and Impact of the Study:  These biochemical keys are designed for use in routine applications, particularly in environmental and clinical studies involving a high number of isolates.