Evaluation of a test-kit (Oxi/Ferm system) for identification of vibrios

A total of 258 strains belonging to different species of Vibrio isolated from various sources in different parts of the world were subjected to identification by Oxi/Ferm tube and conventional tests sometimes extending to 250 characters when the conventional tests failed to recognise them. Nearly 88 per cent of them could be identified accurately in this system at the species level. The strains designated as mannitol negative vibrios and Vibrio species were also identified properly as V. cholerae. However, the system recognised V. fluvialis (Group F vibrios) as Aeromonas hydrophila and some strains of L vibrios and V. parahaemolyticus as V. cholerae. Those strains that could be identified properly corresponded to one or more ID values of the kit. A few additional supplemental tests based on stable characters are recommended for inclusion to those ID values to identify all the vibrios accurately and in case of V. cholerae up to biotype level. Some of these tests are already included in the supplementary list of the system, the only change required is to put them against respective ID values. Reactions within the system were reproducible. This study establishes the utility of the convenient Oxxi/Ferm system for rapid and easy identification of the different members of the family Vibrionaceae including the newly recognised ones with few additional tests.