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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Integrated Aquatic Animal Health Strategies

Location: Aquatic Animal Health Research

2013 Annual Report


1a.Objectives (from AD-416):
Objective 1 - Determine population and strain responses to vaccines and infectious pathogens (e.g., Edwardsiella ictaluri, Flavobacterium columnare), using genetically characterized fish. Objective 2 - Determine characteristics of coinfections and their role in disease processes in aquaculture and aquatic environments. Objective 3 - Identify microbial pathogen genes and pathways critical for host pathogenesis and immunity. Objective 4 - Develop and validate new and novel pathogen detection tests for Edwardsiella ictaluri, Flavobacterium columnare, Streptococcus iniae and S. agalactiae using genomic, proteomic, microbiological and immunological approaches.


1b.Approach (from AD-416):
Fish farmers continue to identify disease as a significant negative impact on profitability. Therefore, the goal of this project is to improve fish health and reduce this negative impact. Using a multi-disciplinary approach, we will accomplish four objectives that address important questions about bacterial diseases that affect the catfish (e.g., Edwardsiella ictaluri, Flavobacterium columnare) and tilapia (e.g., Streptococcus iniae, S. agalactiae) industries. Studies will be conducted at the gene, protein, individual, and/or population levels. Questions remain about some barriers to optimum vaccine efficacy in the field and about the responses of current and future strains of fish to pathogens and vaccines. Therefore, Objective 1 will determine population and strain responses to vaccines and infectious pathogens (e.g., E. ictaluri, F. columnare), using genetically characterized fish. In most intensive aquaculture production systems, multiple pathogens are present and result in mortality. Objective 2 will determine characteristics of coinfections and their role in disease processes in aquaculture and aquatic environments. Objective 3 will identify microbial pathogen genes and pathways critical for host pathogenesis and immunity that will provide important information for future vaccine development. Objective 4 will develop and validate new and novel pathogen detection tests for E. ictaluri, F. columnare, S. iniae and S. agalactiae so that these can be used in fish health management. The results from this work will contribute to present and future vaccine development, provide useful management information about farm use of vaccines and coinfections, and leverage development of future catfish strains being developed for the industry.


3.Progress Report:
Substantial progress was made to evaluate channel catfish families that were selectively bred for resistance against Edwardsiella (E.) ictaluri for susceptibility to Flavobacterium (F.) columnare infection. Data demonstrated that there may be a negative correlation between the resistance of catfish to F. columnare and their resistance to E. ictaluri. Substantial progress was made on the co-infection of Gyrodactylus and F. columnare. Research results revealed that the infection of Gyrodactylus increased the susceptibility of fish to infection of F. columnare. Substantial progress was made to determine factors influencing the vectoring ability of parasites for bacterial pathogens. The influence of 20 different lectins on the ability to affect the attachment of bacteria E. ictaluri to the theront Ichthyophthirius (Ich) was evaluated. Substantial progress was made to expand proteomic work for a large panel of F. columnare isolates for comparative proteomics. No clear association between virulence to tilapia and genomovar type of these isolates were found. Significant progress was made to identify immune genes of channel catfish in response to infection or vaccination of Aeromonas (A.) hydrophila. Significant progress was made to characterize the extracellular proteins of A. hydrophila. Significant progress was made to develop and evaluate attenuated vaccines to protect catfish and tilapia against Edwardsiella tarda and A. hydrophila. Attenuated vaccines have been developed and invention disclosures have been filed. Significant progress was made to develop and evaluate recombinant Deoxyribonucleic acid (DNA) vaccine against the protozoan parasite Ich. The efficacy studies on these recombinant DNA vaccines were determined.


4.Accomplishments
1. Attenuated polyvalent vaccine developed to protect tilapia against Streptococcus agalactiae. Streptococcosis caused by Streptococcus (S.) agalactiae is a hyperacute systematic disease that affects both cultured and wild fish species in various aquatic environments (freshwater, estuarine, and marine). ARS researchers at Auburn, Alabama, developed an attenuated polyvalent vaccine to protect tilapia against infections by both biotype I and biotype II strains of S. agalactiae. The attenuated polyvalent vaccine offered significant protection to tilapia against infections of S. agalactiae. The use of this polyvalent vaccine will protect tilapia against streptococcosis caused by S. agalactiae.

2. Attenuated vaccine developed to protect catfish and tilapia against Edwardsiella tarda. Bacterial diseases caused by Edwardsiella (E.) tarda are plaguing the aquaculture industry, causing losses to be estimated in millions of dollars annually. ARS researchers at Auburn, Alabama, developed an attenuated vaccine Eta30305NOVO that was found to be safe and highly efficacious in protecting fish against infection of E. tarda. The use of this vaccine will prevent future disease outbreaks in catfish and tilapia caused by E. tarda.

3. Attenuated vaccine developed to protect catfish against Aeromonas hydrophila. Disease outbreaks caused by Aeromonas (A.) hydrophila is causing economic loss in millions of dollars annually. ARS researchers at Auburn, Alabama, have developed an attenuated vaccine AH11NOVO to protect catfish against A. hydrophila infection. AH11NOVO was found to offer 100% protection to catfish against infections of A. hydrophila. The use of this vaccine will prevent future disease outbreaks in catfish caused by A. hydrophila.

4. Virulence factors identified in the highly virulent West Alabama isolate of Aeromonas hydrophila. Disease outbreaks caused by Aeromonas (A.) hydrophila have led to an estimated loss of more than $3 million annually in West Alabama. ARS researchers at Auburn, Alabama, identified virulence factors of these highly virulent isolates of A. hydrophila, including hemolysin, aerolysin, elastase (metalloprotease), nuclease, and nucleotidase. The identification of these virulence factors will provide novel strategies to control disease outbreaks caused by these highly virulent A. hydrophila.

5. Compare immune responses against parasite Ichthyophthirius between channel catfish and hybrid catfish. The hybrid catfish (female channel catfish x male blue catfish) has been reported to exhibit many commercially desirable characteristics, including faster growth, better feed conversion, and resistance to diseases. There is limited information available on the immune protection of hybrid catfish against parasite Ichthyophthirius (Ich). ARS scientists in Auburn, Alabama, compared immune response and host protection between channel catfish and hybrid catfish to evaluate a fish immune protection against the parasite. The immunized channel catfish and hybrid catfish showed a higher anti-Ich antibody level and higher survival (90-100%) than non-immunized controls (0%). Overall results indicated that hybrid catfish could develop the same strong immune protection against Ich as its parent channel catfish. These study results will help fish farmers and fish breeders to select disease resistant fish to minimize the impact of disease on cultured fish.


Review Publications
Yeh, H., Klesius, P.H. 2012. Channel catfish (Ictalurus punctatus Rafinesque, 1818) tetraspanin membrane protein family: Identification, characterization and phylogenetic analysis of tetraspanin 3 and tetraspanin 7 (CD231) transcripts. Fish Physiology and Biochemistry Journal. 38:1553-1563.

Yeh, H., Klesius, P.H. 2012. Construction, expression and characterization of eleven putative flagellar apparatus genes of Aeromonas hydrophila AL09-73. Journal of Fish Diseases. 35:853-860.

Yeh, H., Klesius, P.H. 2013. Changes of serum myeloperoxidase and nitric oxide in the early stage of Edwardsiella ictaluri infection in channel catfish, Ictalurus punctatus. Journal of Fish Diseases. 36:441-446.

Lafrentz, B.R., Lapatra, S.E., Shoemaker, C.A., Klesius, P.H. 2012. Reproducible challenge model to investigate the virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss. Diseases of Aquatic Organisms. 101:115-122.

Xu, D., Shoemaker, C.A., Zhang, Q., Klesius, P.H. 2012. Naturally infected channel catfish (Ictalurus punctatus) concurrently transmit Ichthyophthirius multifiliis and Edwardsiella ictaluri to naive channel catfish. Aquaculture. 376-379:133-136.

Xu, D., Klesius, P.H. 2013. Comparison of serum antibody responses and host protection against parasite Ichthyophthirius multifiliis between channel catfish and channel x blue hybrid catfish. Fish and Shellfish Immunology. 39:1356-1359.

Qiao, G., Jang, I., Won, K., Woo, S., Xu, D., Park, S. 2012. Pathogenicity comparison of high and low virulent strains of Vibrio scophthalmi in olive flounder (Paralichthys olivaceus). Fisheries Sciences. 79:99-109.

Wei Pridgeon, Y., Klesius, P.H., Aksoy, M.Y. 2013. Attempt to develop live attenuated bacterial vaccines by selecting resistance to gossypol, proflavine hemisulfate, novobiocin, or ciprofloxacin. Vaccine. 31:2222-2230.

Bebak, J.A., Garcia, J.C., Darwish, A.M. 2012. Effect of copper sulfate on Aeromonas hydrophila infection in channel catfish (Ictalurus punctatus) fingerlings. North American Journal of Aquaculture. 74(4):494-498.

Wei Pridgeon, Y., Klesius, P.H. 2012. Major bacterial diseases in aquaculture and their vaccine development. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources. 7(048):1-16.

Lafrentz, B.R., Shoemaker, C.A., Booth, N.J., Peterson, B.C., Ourth, D.C. 2012. Spleen index and mannose-binding lectin levels in four channel catfish Ictalurus punctatus families exhibiting different susceptibilities to Flavobacterium columnare and Edwardsiella ictaluri. Journal of Aquatic Animal Health. 24:141-147.

Shoemaker, C.A., Lafrentz, B.R., Klesius, P.H. 2012. Bivalent vaccination of sex reversed hybrid tilapia against Streptococcus iniae and Vibrio vulnificus. Aquaculture. 354-355:45-49.

Gliniewicz, K., Plant, K.P., Lapatra, S.E., Lafrentz, B.R., Cain, K., Snekvik, K.R., Call, D.R. 2012. Comparative proteomic analysis of virulent and rifampicin attenuated Flavobacterium psychrophilum. Journal of Fish Diseases. 35:529-539.

Xu, D., Klesius, P.H., Bosworth, B.G., Chatakondi, N.G. 2012. Susceptibility of three strains of blue catfish to parasite Ichthyophthirius multifiliis. Journal of Fish Diseases. 35(12):887-895.

Shoemaker, C.A., Martins, M.L., Xu, D., Klesius, P.H. 2012. Effects of Ichthyophthirius multifiliis parasitism on the survival, hematology and bacterial load in channel catfish previously exposed to Edwardsiella ictaluri. Parasitology Research. 111(5):2223-2228.

Qiao, G., Park, S., Xu, D. 2012. Clinical, hematological and biochemical alterations in olive flounder, Paralichthys olivaceus following experimental infection by Vibrio scophthalmi. Canadian Journal of Fisheries and Aquatic Sciences. 15(3):233-239.

Darwish, A.M., Bebak, J.A., Schrader, K. 2012. Assessment of Aquaflor (c), copper sulfate and potassium permanganate for control of Aeromonas hydrophila and Flavobacterium columnare infection in sunshine bass, Morone chrysops female x Morone saxatilis male. Journal of Fish Diseases. 35:637-647.

Wei Pridgeon, Y., Klesius, P.H., Song, L., Zhang, D., Kojima, K., Mobley, J. 2013. Identification, virulence, and mass spectrometry of toxic ECP fractions of West Alabama isolates of Aeromonas hydrophila obtained from a 2010 disease outbreak. Veterinary Microbiology. 164:336-343.

Wei Pridgeon, Y., Klesius, P.H., Garcia, J.C. 2013. Identification and virulence of Chryseobacterium indologenes isolated from diseased yellow perch (Perca flavescens). Journal of Applied Microbiology. 114:636-643.

Wei Pridgeon, Y., Aksoy, M., Klesius, P.H., Srivastavae, K., Reddy, G. 2012. Attenuation of a virulent Aeromonas hydrophila with novobiocin and pathogenic characterization of the novobiocin-resistant strain. Journal of Applied Microbiology. 113:1319-1328.

Qiao, G., Lee, D., Woo, S., Li, H., Xu, D., Park, S. 2012. Microbiological characteristics of Vibrio scophthalmi isolates from diseased olive flounder Paralichthys olivaceus. Fisheries Sciences. 78(4):853-863.

Wei Pridgeon, Y., Mu, X., Klesius, P.H. 2013. Biochemical and molecular characterization of the novobiocin and rifampicin resistant Aeromonas hydrophila vaccine strain AL09-71 N+R compared to its virulent parent strain AL90-71. Veterinary Microbiology. 165:349-357.

Wei Pridgeon, Y., Li, Y., Aksoy, M.Y., Song, L., Klesius, P.H., Srivastava, K.K., Reddy, P. 2013. Fitness cost, gyrB mutation, and absence of phosphotransferase system fructose specific IIABC component in novobiocin-resistant Streptococcus iniae vaccine strain ISNO. Veterinary Microbiology. 165:384-391.

Last Modified: 9/10/2014
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