|
Principal Investigator: Dr. Theodore Clark
Contact Information: E-mail: tgc3@cornell.edu - Phone: 607-253-4042
Sponsor: USDA-Federal Formula Funds
Grant Number: 2005-06-051
Title: Controlling White Spot Disease in Fish: Development of New Antigens and Methods for Vaccine Delivery
Annual Direct Cost: $30,000
Project Period: 10/01/05-09/30/08
NON-TECHNICAL SUMMARY: Our long-term goal is the development of an effective vaccine against Ichthyophthirius multifiliis (Ich), a protozoan parasite that has major impact on commercial aquaculture worldwide. Ich is highly pathogenic and readily kills fish. Nevertheless, animals that survive infection develop a long-term, acquired immunity to subsequent challenge. In previous studies, we showed that a family of parasite membrane proteins (the so called i-antigens) confers strong immunity against Ich when administered to naïve fish in an injectable form. This proposal will attempt to develop a more practical, oral/immersion-based vaccine that could be delivered to fish while still in the pond. In addition, we intend to isolate and characterize additional i-antigen variants from field isolates obtained in New York and elsewhere. If successful, this work will provide an effective vaccine against Ich, along with a novel delivery system that should be directly applicable to
many other pathogens of farmed fish.
OBJECTIVES: Our research is directed towards the control of Ichthyophthirius multifiliis (Ich), the causative agent of white-spot disease in farm-raised fish. While Ich is highly pathogenic, animals that survive infection resist subsequent challenge, and the target antigens responsible for immunity (so called i-antigens) have now been identified. Nevertheless, the degree to which these antigens vary in natural populations is unknown. Furthermore, while a prototype injectable vaccine for this agent has been developed, simpler oral/immersion vaccine delivery systems would be extremely useful to the aquaculture industry. To address these issues, we plan to sample parasite isolates from disease outbreaks in New York and other regions of the country, and categorize them with respect to i-antigen serotype using reference antisera against existing strains. Novel strains will be used to isolate variant i-antigen genes, and new reference sera will be prepared for use in future serotyping efforts. This survey will provide important information relative to antigenic variation among existing strains, and provide new targets for potential vaccine development. In addition, we will attempt to develop new methods for oral/immersion delivery of vaccine antigens to fish. Success in this arena will contribute not only to the prevention of Ich, but will be directly applicable to other microbial diseases of farm-raised and ornamental fish.
|
