Live attenuated
A live attenuated Edwardsiella ictaluri bacterium lacking a viable gene encoding a functional evpB protein and a method of using the same to protect fish against infection from virulent Edwardsiella ictaluri . The methods and compositions for protecting fish against infection from virulent Edwardsiella ictaluri comprising administering to a fish a therapeutically effective amount of an attenuated Edwardsiella ictaluri bacterium lacking a viable gene encoding a functional EvpB protein. The bacterium may include an insertion and/or deletion mutation in the evpB gene. The fish include catfish, preferably catfish fingerling or a catfish fry. The composition may be delivered via immersion delivery, an injection delivery, an oral delivery, or combinations thereof.
1. A vaccine for protecting fish against Edwardsiella ictaluri infection comprising an immunogenically effective amount of an attenuated Edwardsiella ictaluri bacterium, the bacterium lacking a viable gene encoding a functional EvpB protein by having a deletion of the coding sequence of the evpB gene.
2. A composition comprising an amount of live attenuated Edwardsiella ictaluri bacterium sufficient for protecting fish against infection from virulent Edwardsiella ictaluri , the bacterium lacking a viable gene encoding a functional EvpB protein by having a deletion of the coding sequence of the evpB gene, and one or more of the group consisting of a pharmaceutically-acceptable vehicle, a carrier, and an excipient.
3. The composition of claim 2 , wherein the composition is formulated for delivery to fish by the method selected from the group consisting of an immersion delivery, an injection delivery, an oral delivery, or combinations thereof.
4. A method for protecting fish against infection from virulent Edwardsiella ictaluri comprising: administering to a fish a therapeutically effective amount of an attenuated Edwardsiella ictaluri bacterium lacking a viable gene encoding a functional EvpB protein by having a deletion of the coding sequence of the evpB gene.
5. The method of claim 4 , wherein the administering step is selected from a group consisting of immersion delivery, injection delivery, oral delivery, and combinations thereof.
6. The method of claim 4 , wherein the fish is a catfish.
7. The method of claim 4 , wherein the attenuated Edwardsiella ictaluri bacterium is mixed with a fish feed to form a fish feed mixture, and wherein the fish feed mixture is delivered to the fish for oral consumption.