Formulation of a Novel Phage Cocktail against Vibrio cholerae O1

Abstract

A number of 26 phages lytic for 26 isolates of V. cholerae O1, biotype El Tor, Serotype Inaba are isolated from sewage water. The phage isolates showed host range of 35-65% against V. cholerae O1 by spot lysis methods. The morphological properties of plaques formed on the top agarose are studied and showed that most virulent phages had larger diameter (in millimeter) with regular or irregular margin cut and clear plaque comparing with smaller diameter and turbid plaque for those less virulent phages. A total of 8 phages are selected for formulation the phage cocktail in order to extend the host-range of phages in cocktail collectively. The %inhibition assay for every single phage of the 8 phages selected for formulation of phage cocktail ranged from 0-75, whereas that of the 8 phages cocktail was 100%inhibition against all V. cholerae O1 isolates. The formulation of the 8 phages in a cocktail proved to an effective approach to achieve the broad host-range activity towards V. cholerae O1 isolates and made it possible to go forwards the animal model for further studies on phage therapy for animal model of cholera.