Source: MISSISSIPPI STATE UNIV submitted to
HEALTH MANAGEMENT, DISEASE PREVENTION AND CONTROL STRATEGIES IN CATFISH AQUACULTURE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
REVISED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
1004524
Grant No.
(N/A)
Project No.
MIS-371660
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Sep 9, 2014
Project End Date
Sep 30, 2018
Grant Year
(N/A)
Project Director
Wise, D.
Recipient Organization
MISSISSIPPI STATE UNIV
(N/A)
MISSISSIPPI STATE,MS 39762
Performing Department
Delta Research & Extension Center
Non Technical Summary
Research in the area of fish health management and diagnostic medicine will establish new effective measure for the early detection, prevention and treatment of significant pathogens effecting catfish production. Reducing disease-related costs would substantially increase net profitability of catfish farming and help ensure the economic viability of the catfish industry. Advances in the understanding of disease transmission, pathogenesis, and epidemiology, along with the development of state of the art diagnostic technologies will provide benefits to the scientific community and fish health providers throughout the United States. This project builds on past projects to refine disease surveillance programs, treatment strategies and management practices. The objectives focus on the diagnostic surveillance to identify emerging diseases, the development of rapid diagnostic procedures for important pathogens, evaluation of therapeutic agents and vaccines, and the development and implementation of practical management strategies to improve fish health and production efficiency.
Animal Health Component
100%
Research Effort Categories
Basic
10%
Applied
70%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
3113710106010%
3113710104020%
3113710109010%
3113710110020%
3113710116020%
3113710110310%
3113710117010%
Knowledge Area
311 - Animal Diseases;

Subject Of Investigation
3710 - Catfish;

Field Of Science
1170 - Epidemiology; 1060 - Biology (whole systems); 1090 - Immunology; 1160 - Pathology; 1100 - Bacteriology; 1040 - Molecular biology; 1103 - Other microbiology;
Goals / Objectives
In 2011, more than 152 million kg of farm-raised catfish, valued at approximately $423 million, was produced in the United States. Despite the prosperity of the past few decades, the U.S. catfish industry is threatened by increasing disease losses, low fish prices, foreign competition and high feed costs. Collectively these factors contributed to a 50% decline in farm acreage over the past few years and continued economic hardship threatens the viability of more operations. Improvements in fish health management and production strategies are needed to maintain market shares in a competitive global market. This project addresses practical, production-oriented problems, identified by industry advisory groups, through research derived management programs designed to improve fish health and production efficiencies. This project builds on past projects to refine disease surveillance programs, treatment strategies and management practices. The first objective focuses on recognition and pathogenicity of emerging diseases and development of rapid diagnostic procedures for important catfish pathogens. This approach will utilize diagnostic records to monitor disease trends occurring in the channel, blue and channel x blue hybrid catfish. The second objective will investigate the responses of channel, hybrid and blue catfish to therapeutic agents and vaccines against important bacterial pathogens. The final objective will focus on the development and implementation of practical management strategies to improve fish health and production efficiency.
Project Methods
Objective 1: Investigate new and emerging diseases, and develop rapid diagnostic procedures for important pathogens of channel, hybrids and blue catfish.The Aquatic Research & Diagnostic Laboratory (ARDL) in Stoneville serves as a valuable resource to catfish producers in Mississippi and the surrounding states (Alabama, Arkansas, Louisiana and Texas) and is utilized by a broad cross section of the catfish industry. Diagnostic records provide critical insight to changes in disease trends and emergence of new diseases affecting animal production systems, an essential component of population health management. This provides clinicians, caregivers and researchers a good cross-section of disease occurrence across the industry. Information will be used to prioritize the allocation of resources in the development of rapid diagnostic procedures, disease surveillance and treatment programs and implementation of biosecurity measures to stop the spread of emerging diseases when possible. Research will focus on the pathogenicity and development of new molecular diagnostic tests for E. tarda, E. piscicida and E. piscicida-like sp., as well as both genomovars of F. columnare. Multiplex assays will be developed to allow for simultaneous detection of major bacterial and parasitic infections causing significant losses in cultured catfish. These assays will be utilized in on-going disease surveillance programs and aide in diagnostic evaluations. The susceptibility of channel catfish, blue catfish and blue x channel catfish hybrids to parasitic and bacterial infections will be evaluated by experimentally infecting fish with target pathogens and monitoring infection rates, mortality and histopathology. Information will be used to identify priority pathogens in different species of cultured catfish. Information obtained from this work will be used to identify significant disease risks to catfish production and develop species specific disease management programs.Objective 2: Investigate the responses of channel, hybrid and blue catfish to therapeutic agents and oral vaccines for important bacterial pathogens.Research will be conducted to define minimum inhibitory concentration (MIC) and cut-off values for clinical bacterial pathogens against 3 commercially available antibiotics. This information is critical to policy review concerning antibiotic approval in the catfish industry. Separately, research will be conducted to optimize the effectiveness of oral vaccination and determine environmental factors which may limit vaccine efficacy and safety.Evaluation of therapeutic agents - In vitro and in vivo analysis of antibiotic sensitivity will be determined from bacterial pathogens recovered and archived from diagnostic case submissions. Information will be used to tract potential patterns in antibiotic resistance to ensure the judicious use medicated feeds labeled for use in catfish production. Minimal Inhibitory Concentration and zone diameters of inhibition values will be established for Edwardsiella ictaluri, E. tarda and E. piscicida against Aquaflor, Romet and Terraymcin. Isolates demonstrating varying degrees of antibiotic resistance will be used in disease challenge trials to correlate in-vivo resistance patterns to treatment failure. Wild type catfish bacterial pathogens and non-wild type bacteria (isolates show varying degrees of resistance) will be used to establish experimental infections in channel catfish followed by treatment with antimicrobial medicated feed. Data will be analyzed for differences in fish mortality, feeding activity, and weight changes between antimicrobial medicated groups exposed to wild type vs. non wild type bacteria. Information will be used by fish health veterinarians to make science based recommendations on the use of medicated feedsExperimental vaccination trials - The optimal age for orally vaccinating fish against E. ictaluri infection and factors affecting vaccine safety and efficacy will be evaluated in laboratory trials. Channel catfish will be vaccinate at 30, 50, and 70 days of age using a live attenuated vaccine delivered orally. Following vaccination fish will be observed daily for dead and sick fish to document vaccine safety and possible adverse reactions to vaccination. Fish will be exposed to a virulent culture of E. ictaluri 30 d after vaccination to establish vaccine efficacy. In subsequent trials fish will be subject to low oxygen levels and confinement to create a stress events before and after vaccination. Mortality following vaccination but prior to disease challenge will be used to determine if stress effects vaccine safety and mortality following challenge will be used to determine if stress can diminish protection offered through vaccination. Information will be used to establish field vaccination protocols and develop label recommendations.Objective 3: Develop and implement practical management strategies to improve fish health and production efficiency.Field studies will be conducted to evaluate practical management strategies for controlling two diseases which account for more than half of the diagnostic case submissions to the Aquatic Research and Diagnostic Laboratory (ARDL). Research will focus on development management strategies for controlling proliferative gill disease (PGD), caused by the myxozoan parasite Henneguya ictaluri and field evaluation of an oral vaccine for control of enteric septicemia of catfish (ESC) caused by the gram-negative bacteria Edwardsiella ictaluri. These management approaches have the potential to greatly reduce the impact of these diseases, that are estimated to cost the catfish industry $60-80 million annually.Proliferative gill disease - Channel and hybrid catfish will be raised in 1.0 acre research ponds and harvested and re-stocked on a yearly basis for 4 years. At the end of each grow-out period, ponds will be clean harvested and restocked. Ponds will not be dried between production cycles. Water samples will be collected and processed according to protocols established in our laboratory to estimate the approximate concentration of Henneguya ictaluri actinospores in catfish ponds over the course of the study. The life cycle for this parasite involves a fish host and ubiquitous benthic oligochaete. Previous research has demonstrate hybrid catfish maybe a dead-end host for this disease providing an opportunity to limit life cycle development in the fish host. This work will evaluate the use of hybrid catfish in rotation with channel catfish as a management strategy to control the severity of PGDCommercial field vaccination trials - To demonstrate operational development of the oral vaccination platform, vaccination trials will be conducted on commercial fingerling operations. Catfish will be orally vaccinated when fish are between 50 and 70 days of age post hatch. The number of viable vaccine isolates per gram of feed will be determined from vaccine/feed admixtures sampled during the course of delivery to verify dose. Vaccinated ponds will be randomly paired with non-vaccinated ponds on the day of vaccination. Vaccinated fish will be monitored daily for adverse reactions (decreased feed consumption, morbidity, mortality) to vaccination for 21 days to document vaccine safety. Paired ponds will be clean harvested at the end of the production cycle as fish are used for sales or transferred to grow-out production ponds. Data collected from field studies will be analyzed by one factor analysis of variance (harvest head and size, feed fed, biomass produced and feed conversion ratio). Data will be used to establish proof of concept for the oral vaccination platform and used to support vaccine licensing.

Progress 10/01/16 to 09/30/17

Outputs
Target Audience:The goal of research in this project is to address high priority, industry-identified issues to increase production efficiencies and profitability of aquaculture in the southeastern United States by improvements in disease management. The target audience for new information and technologies developed from the project will be the U.S. catfish farmer, research scientists, extension specialists, and fish health professionals. Ultimately, American consumers will be the major beneficiaries through the production of an inexpensive, safe, domestically produced seafood product that will help offset the large U.S. trade deficit in seafood commodities. Information derived from this project will be passed to user groups through a formal network of extension program specialists utilizing workshops, seminars, advisory groups, and demonstration projects involving farmer user-groups. Investigators will also deliver findings to other scientist and students of aquaculture through scientific publications and professional meetings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?As part of our mission, the ARDL provides training to veterinary students. Mississippi State University veterinary students who are on their preventive medicine rotation spend a day at the ARDL learning about the industry, management, and the common diseases of catfish. In addition, the ARDL also takes veterinary externs who spend a minimum of 2 weeks at the laboratory. In 2016, there were 4 veterinary externs. Two were from Mississippi State University and one from the University of Pennsylvania and one from Ross University School of Veterinary medicine. The project also supports two doctoral candidates developing expertise in DNA isolation, PCR analysis, genome sequencing, bioinformatics, fish necropsy, and fish health management How have the results been disseminated to communities of interest?Information generated from this project will benefit catfish farmers in the southeastern United States as well as aquaculture research scientists, extension specialists, and fish health professionals. This project will form the framework for the development of integrated fish health management practices that reflect herd health management programs that have been successful in monitoring and controlling diseases in other species of production animals. The project objectives were developed in consultation with the NWAC Industry Liaison Council and the NWAC Fish Health Advisory Committee. Information generated from this project has been disseminated to U. S. catfish farmers, fish health specialist and other research scientist through on-farm demonstration projects, scientific meetings and journal articles, extension workshops and consultation with farmers. What do you plan to do during the next reporting period to accomplish the goals?Scientist will continue to monitor disease prevalence trends using the diagnostic case submissions to help guide the research needs. This would include changes in currently known diseases as well as possible new emerging diseases. Vaccine research will include assessment of cross reactivity of the vaccine isolate to closely related Edwardsiella species, and evaluation of antigenic variation in E. ictaluri field isolates recovered from distinct geographic regions. Pond management strategies will focus on the use of hybrid catfish as a means reducing pathogen loading rates in catfish production systems and use of multiplex PCR assays to assess treatment efficacies and monitor pathogen loading rates in commercial catfish production systems. On-farm disease monitoring and surveillance of atypical Aeromonas hydrophila in catfish production systems has been initiated and will be expanded in the following year. Treatment strategies, risk factors associated with disease outbreaks and mechanisms related to the spread of infection will be evaluated.

Impacts
What was accomplished under these goals? The Aquatic Research and Diagnostic Laboratory (ARDL) offers a comprehensive disease diagnostic service to catfish producers centered in Mississippi and surrounding states, including Alabama, Arkansas, Louisiana, and Texas. Diagnostic records provide critical insight to changes in disease trends and emergence of new diseases affecting catfish production systems. This information provides clinicians, caregivers and researchers a good cross-section of disease occurrence across the industry and is used to prioritize research investment. In addition the ARDL provides diagnostic support for disease and production research at NWAC and has developed rapid molecular diagnostic assays for the detection of all major catfish pathogens from the environment and fish tissues, which are central to on-going disease research projects The ARDL provides a year-end report, based on a calendar year, categorizing diagnostic case submissions. In 2016, the ARDL received a total of 744 cases, 631 submitted by producers and 113 submitted by NWAC researchers. Bacterial diseases represented a majority of case submissions, led by Flavobaterium columnare (columnaris disease) isolated from 40.7% of case submissions and Edwardsiella ictaluri (enteric septicemia of catfish, ESC) from 39.2% of disease cases. Edwardsiella piscicida (formerly E. tarda) was isolated from 51 cases (6.9%), 47 of which were from hybrid catfish. There were 24 atypical Aeromonas hydrophila (aAh) cases (3.2%), a relatively new disease causing tremendous losses on commercial operations in Mississippi, Arkansas and Alabama. Yersinia ruckeri, a previously unreported pathogen was isolated from hybrid catfish on one farm.. Antibiotic sensitivities to Aquaflor, Romet, and Terramycin were performed on all bacterial pathogens isolated from case submissions. Flavobacterium columnare was shown susceptible to all antibiotics, but antibiotic resistance was seen in 25 of the 292 E. ictaluri isolates tested. Comparably, all but one of the E. piscicida and aAh isolates were shown susceptible to antibiotics. The predominant parasitic diseases were proliferative gill disease caused by Henneguya ictaluri (11%) and Bolbophorus trematode infestations (6%), both of which are associated with significant production losses. Similar trends were observed in 2017 and the data will be compiled at year's end. Again, bacterial pathogens were the predominant cause of mortality in commercially produced catfish, led by ESC and columnaris disease. There is increased incidence and prevalence of fish diagnosed with E. piscicida, although this trend seems largely associated with hybrid catfish. Yersinia ruckeri has now been diagnosed in hybrid catfish on different farms. . While mortality appears limited and not widespread Y. ruckeri is now considered a potentially emerging pathogen in catfish aquaculture, similar to E. piscicida. Research is being conducted to develop challenge models and comparative disease susceptibility studies. Cases associated with aAh have decreased compared to previous years but remain a pathogen of serious concern as catastrophic losses have been linked to aAh outbreaks. Atypical A. hydrophila is a relatively new disease causing severe losses in commercially cultured catfish in Mississippi, Arkansas and Alabama. Field research is being conducted evaluating the epidemiology of aAh to identify potential disease vectors, evaluate pathogen loading rates in response to treatment, and determine environmental factors predisposing catfish to infection. Prior to and following an epizootic, fecal and gill swabs were positive for aAh in a relatively high percentage of asymptomatic fish, indicating a carrier state may be involved in the kinetics of infection. In response to infection, medicated feed was shown to greatly reduce this carrier state indicating medicated feed is effective in curtailing losses. Piscivorous birds were shown to be a disease vector and severe outbreaks have been associated with certain species of blue-green algae which may serve as a predisposing factor to outbreaks. This work is part of an on-going project involving multiple institutions. Proliferative gill disease is a parasitic disease caused by Henneguya ictaluri, a myxozoan parasite. The parasite has a complex life cycle involving fish and a benthic oligochaete. Experimental infectivity trials investigating the developmental life stages of H. ictaluri in the fish host demonstrated significantly higher concentrations of H. ictaluri DNA in channel catfish than hybrid catfish across multiple organ systems. Mature myxospores were observed in 36% of channel catfish beginning 6 weeks post exposure. Comparably, mature myxospores were observed in only 1% of hybrid catfish across the same span. This work suggests the development of H. ictaluri is arrested in hybrid catfish and propagation of hybrid catfish may be an effective management strategy to minimize pathogen loading rates. Pond studies are being conducted investigating the effects of hybrid monoculture on the propagation and transmission of H. ictaluri within the system and the potential for hybrid catfish to serve as a biological control for PGD. Edwardsiella piscicida (formerly E. tarda) is an enteric pathogen closely related to E. ictaluri. Incidence and prevalence of E. piscicida has increased in prevalence over the last few years. Research evaluating susceptibility of hybrid and channel catfish to E. piscicida infection showed hybrid catfish are significantly more susceptible to infection. This is in line with diagnostic observations and anecdotal reports from industry that E. piscicida is an emerging disease in hybrid catfish. Cross challenge studies were conducted with E. ictaluri and E. piscicida showing fish surviving E. ictaluri infection were resistant to subsequent exposure to E. piscicida and visa-versa. The efficacy of an ESC vaccine to protect fish against E. piscicida infection is being evaluated. Initial trials indicates the ESC vaccine protects fish against this closely related pathogen. Life cycles of 3 trematodes isolated from catfish production systems have been completed by molecular and host susceptibility studies. The impact these new trematodes on catfish production is being evaluated. A new emergent snail species (Biomphalaria sp.) has been identified as an intermediate host for trematodes Bolbophorus damnificus and Drepanocephalus auritus, both of which are linked to mortality in juvenile catfish. Parasite induced anemia associated with B. damnificus was demonstrated in juvenile catfish and may be linked to decreases in production observed in infested populations of fish. Chemical and biological control of the snail host in catfish ponds is being evaluated. Research conducted under the previous project led to the development of an oral live attenuated vaccine for control of ESC and a mechanized system for oral delivery. Laboratory work has demonstrated the orally delivered vaccine is highly efficacious and safe at 10 times the target dose. Back passage of the vaccine isolate showed no increase in virulence indicating very low potential for reversion to virulence. Evaluation of data from previous field trials demonstrated significant increases in survival, feed fed, feed conversion ratio and yield resulting in increased revenue in vaccinated channel ($2,220-$3,000/acre) and hybrid catfish ($2,500-$3,200/acre catfish. In 2017, 9 commercial catfish producers participated in commercial field trials involving approximately 200 million channel and hybrid catfish. Trials were used to refine protocols for commercial application and validate final design of a mechanized delivery system. The vaccine was also shown to cross protect against a closely related bacterial pathogen, Edwardsiella piscicida. It is anticipated the vaccine will be commercial available by the 2018 catfish production season.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Aarattuthodiyil, S., T. Byars, M. Griffin, L. Khoo, T. Greenway and D. Wise. Evaluation of factors affecting the safety and efficacy of Edwardsiella ictaluri vaccine. 42nd Eastern Fish Health Workshop, East Lansing, MI. April 2017
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Reichley, S. R., C. Ware, T. E. Greenway, L. H. Khoo, B. G. Bosworth, D. J. Wise, M. L. Lawrence, M. J. Griffin. Comparative susceptibility of channel catfish (Ictalurus punctatus), blue catfish (Ictalurus furcatus) and channel x blue hybrid catfish to Edwardsiella anguillarum, Edwardsiella piscicida, and Edwardsiella tarda. Journal of the World Aquaculture Society. September 2017. doi: 10.1111/jwas.12467.
  • Type: Journal Articles Status: Published Year Published: 2016 Citation: Gao D and Gaunt P (2016) Development of new G media for culture of Flavobacterium columnare and comparison with other media, Aquaculture 463: 113122
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Griffin, M. J., L. H. Khoo, T. G. Rosser, N. R. Alberson, S. R. Reichley, T. E. Greenway, D. J. Wise and L. M. Pote. Encapsulation of Bolbophorus damnificus (Digenea: Bolbophoridae) metacercariae in juvenile channel catfish, Ictalurus punctatus, is linked to delayed-onset mortality. Journal of World Aquaculture Society. DOI: 10.1111/jwas.12472
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Alberson, N. R., T. G. Rosser, L. H. Khoo, S. K. Buddenborg, E. S. Loker, T. D. Richardson, E. T. Woodyard, L. M. Pote, and M. J. Griffin. 2017. North and South American haplotypes of Drepanocephalus auritus (Digenea: Echinostomatidae) are released from Biomphalaria havanensis (Mollusca: Planorbidae) inhabiting catfish aquaculture ponds in Mississippi, USA. Comparative Parasitology. 84:87-101.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mischke, C. C., M. J. Griffin, M. H. Li, D. J. Wise, and T. E. Greenway. 2017. Postponed feeding does not substantially reduce production expense during pond rearing of hybrid catfish fry. North American Journal of Aquaculture 79:135-139.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Greenway, T.E., T. S. Byars, R. B. Elliot, X. Jin, M. J. Griffin and D. J. Wise. 2017. Validation of fermentation and processing procedures for the commercial scale production of a live attenuated Edwardsiella ictaluri vaccine for use in commercial catfish aquaculture. Journal of Aquatic Animal Health. 29:83-88.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Rosser, G., N. R. Alberson, E. T. Woodyard, F. L. Cunningham, L. M. Pote and M. J. Griffin. 2017. Clinostomum album n. sp. and Clinostomum marginatum Rudolphi, 1819 parasites of the great egret Ardea alba L. from Mississippi, USA. Systematic Parasitology 94:35-49
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Rosser, T. G., W. A. Baumgartner, N. R. Alberson, E. T. Woodyard, S. R. Reichley, L. H. Khoo, D. J. Wise, D. T. King, F. L. Cunningham, and M. J. Griffin. Advancing our understanding of trematodes of farm-raised catfish in the southeastern United States. American Fisheries Society Fish Health Section Annual Meeting, East Lansing, MI. April 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Hendrix, M., S. Reichley, L. Khoo, P. Gaunt, D. Wise, T. Welch, E. Soto and M. Griffin. Yersinia ruckeri from farm-raised channel x blue hybrid catfish in Mississippi. American Fisheries Society Fish Health Section Annual Meeting, East Lansing, MI. April 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Reichley, S. R., M. J. Griffin, C. Ware, G. C. Waldbieser, H. C. Tekedar, T. E. Greenway, L. H. Khoo, M. L. Lawrence, P. S. Gaunt, and D. J. Wise. Expanding our knowledge of Edwarsdiella. American Fisheries Society Fish Health Section Annual Meeting, East Lansing, MI. April 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Reichley, S. R., M. L. Lawrence, T. E. Greenway, L. H. Khoo, D. J. Wise and M. J. Griffin. Advancing our knowledge of the bacteria formerly known as Edwardsiella tarda. 42nd Eastern Fish Health Workshop, East Lansing, MI. April 2017
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Griffin, M. J. Misclassifications: Limitations of 16S Sequencing and Misplaced Reliance on Public Nucleotide Databases. 42nd Eastern Fish Health Workshop, East Lansing, MI. April 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Alberson, N. R., T. G. Rosser, D. T. King, L. H. Khoo, D. J. Wise, E. T. Woodyard, L. M. Pote and M. J. Griffin. Elucidation Of The Life Cycle Of Drepanocephalus auritus, A Digenetic Trematode Infecting The Double-Crested Cormorant Phalacrocorax auritus, The Marsh Ramshorn Snail Planorbella trivolvis, And The Channel Catfish Ictalurus punctatus. 42nd Eastern Fish Health Workshop, East Lansing, MI. April 2017
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: Rosser, T. G., L. H. Khoo, L. M. Pote, D. J. Wise, T. E. Greenway, N. A. Alberson, S. R. Reichley, E. T. Woodyard, and M. J. Griffin. Arrested Development Of Henneguya ictaluri (Cnidaria: Myxobolidae) In Channel x Blue Hybrid Catfish. 42nd Eastern Fish Health Workshop, East Lansing, MI. April 2017


Progress 10/01/15 to 09/30/16

Outputs
Target Audience:The goal of research in this project is to address high priority, industry-identified issues to increase production efficiencies and profitability of aquaculture in the southeastern United States by improvements in disease management. The target audience for new information and technologies developed from the project will be the U.S. catfish farmer, research scientists, extension specialists, and fish health professionals. Ultimately, American consumers will be the major beneficiaries through the production of an inexpensive, safe, domestically produced seafood product that will help offset the large U.S. trade deficit in seafood commodities. Information derived from this project will be passed to user groups through a formal network of extension program specialists utilizing workshops, seminars, advisory groups, and demonstration projects involving farmer user-groups. Investigators will also deliver findings to other scientist and students of aquaculture through scientific publications and professional meetings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?As part of our mission, the ARDL provides training to veterinary students. Mississippi State University veterinary students who are on their food animal rotation (this has been changed to the preventive medicine rotation) spend a day at the ARDL learning about the industry, management, and the common diseases of catfish. In addition, the ARDL also takes veterinary externs who spend a minimum of 2 weeks at the laboratory. In 2015, there were 3 veterinary externs who hailed from the University of Florida, the University of Illinois and the University of Prince Edward Island. The project also supports two doctoral candidates developing expertise in DNA isolation, PCR analysis, genome sequencing, bioinformatics, fish necropsy, and fish health management. How have the results been disseminated to communities of interest?Information generated from this project will benefit catfish farmers in the southeastern United States as well as aquaculture research scientists, extension specialists, and fish health professionals. This project will form the framework for the development of integrated fish health management practices that reflect herd health management programs that have been successful in monitoring and controlling diseases in other species of production animals. The project objectives were developed in consultation with the National Warmwater Aquaculture Center Industry Liaison Council and the National Warmwater Aquaculture Center Fish Health Advisory Committee. Information generated from this project has been disseminated to U. S. catfish farmers, fish health specialist and other research scientist through on-farm demonstration projects, scientific meetings and journal articles, extension workshops and consultation with farmers. What do you plan to do during the next reporting period to accomplish the goals?Scientist will continue to monitor disease prevalence trends using the diagnostic case submissions to help guide the research needs. This would include changes in currently known diseases as well as possible new emerging diseases. Additional in vitro tests will be conducted to evaluate MIC testing methods for catfish bacterial pathogens. Vaccine research will include expansion of commercial field trials, production of a vaccine delivery system with greater capacity, assessment of cross reactivity of the vaccine isolate to closely related Edwardsiella species, and evaluation of antigenic variation in E. ictaluri field isolates recovered from distinct geographic regions. Pond management strategies will focus on the use of hybrid catfish as a means reducing pathogen loading rates in catfish production systems and use of multiplex PCR assays to assess treatment efficacies and monitor pathogen loading rates in commercial catfish production systems. On-farm disease monitoring and surveillance of atypical Aeromonas hydrophila in catfish production systems has been initiated and will be expanded in the following year. Treatment strategies, risk factors associated with disease outbreaks and mechanisms related to the spread of infection will be evaluated.

Impacts
What was accomplished under these goals? This project addresses practical, production-oriented problems, identified by industry advisory groups, through research derived management programs designed to improve fish health and production efficiencies. Annual reports generated from diagnostic case submissions documented changes in the prevalence of diseases afflicting cultured catfish. The predominate diseases were associated with infection caused by Flavobacterium (F.) columnare and Edwardsiella (E.) ictaluri but several emerging diseases have been identified. Most notably is E. piscicida which has increased in prevalence due to an increase in the use of hybrid catfish as a culture species. Atypical Aeromonas (A.) hydrophila, associated with high mortality in west Alabama and east Mississippi has been sporadically recovered from disease case submissions in the Delta region of west Mississippi. Molecular methods have been developed to differentiate E. piscicida from E. ictaluri as well as the atypical A. hydrophila from the typical A. hydrophila that is predominantly an opportunistic pathogen secondary to other disease agents or poor water quality. More recently, Yersinia ruckeri the causative agent of enteric redmouth disease in salmonids was isolated from diagnostic submissions and preliminary studies are underway to determine if this is an emerging pathogen of concern. There has been some antibiotic resistance observed in E. ictaluri case isolates, although this resistance is mostly to Terramycin with some intermediate resistance to Aquaflor. With regards to parasites, Proliferative Gill Disease caused by the myxozoan Henneguya (H.) ictaluri continues to be the most prevalent parasitic disease based on case submissions, although there was a drop in 2015 which could be related to an increased acreage used in the production of hybrid catfish. Comparatively, although the number of digenetic trematode Bolbophorus (B.) damnificus cases are relatively low (10 year average of less than 3% of total submissions) it appears to be a significant problem in 2016, as case submissions currently exceed the 10 year average. Drepanocephalus (D.) auritis is another digenetic trematode infective to catfish showing significant pathology in catfish fingerlings. At present a multiplex real-time polymerase chain reaction (PCR) assay has been developed and validated for the four Edwardsiella spp. considered to be fish pathogens (E. ictaluri, E. piscicida, E. tarda, E. anguillarum), allowing for the simultaneous detection and quantification of all four pathogens in a single reaction. Similar assays have been evaluated for detecting multiple catfish pathogens for use in field surveillance, coupled with an internal reference standard to identify the presence/absence of inhibitors in field samples and are in the final stages of development. Scientists at the Thad Cochran National Warmwater Aquaculture Center, Stoneville, MS, are cooperating with researchers at the US Food and Drug Administration (FDA) and Louisiana State University in establishing uniform criteria to determine whether bacteria isolated from catfish are susceptible or resistant to antibiotics in medicated feed. Research is continuing on establishing the breakpoints for E. ictaluri. The Clinical and Laboratory Standards Institute (CLSI) states the minimal inhibitory concentration (MIC) are determined at 24 hours (h). Work is being conducted to modify CLSI requirements to extend test limits to 48 h to account for slow growing bacterial species such as E. ictaluri. In addition, all three laboratories are currently researching the breakpoints for A. hydrophila and F. columnare. This information will provide uniform measurements to determine the susceptibility of bacteria to antimicrobials and improve diagnosticians' abilities throughout the world to choose appropriate antimicrobial agents to control mortality associated with bacterial agents Malacological surveys have identified a second snail host (Biomphalaria sp.) that transmits B. damnificus and D. auritus, with parasites released by this host showing infectivity to catfish. Experimental life cycle studies are ongoing, but preliminary data has shown double crested cormorants fed catfish experimentally infected with D. auritus develop patent trematode infections, suggesting catfish can serve as an intermediate host in the D. auritus life cycle. Similarly, malacological surveys have linked cercariae released by Biomphalaria sp. to several trematode species in the family Diplostomidae, which cause ocular diplostomiasis in fish worldwide. Experimental challenges have demonstrated at least one of these species (Austrodiplostomum ostrowkiae) causes ocular diplostomiasis in channel catfish. Moreover, research has identified a parasite induced anemia associated with the encapsulation process of B. damnificus in channel catfish, which coincided with mortality in experimentally challenged fish. Research into the effects of H. ictaluri, the causative agent of proliferative gill disease (PGD) in channel and hybrid catfish continues. Studies investigating the in vivo development of H. ictaluri have shown the parasite undergoes arrested or stunted development in hybrid catfish, as mature H. ictaluri spores are typically observed 6-12 weeks post infection in channel catfish, but have not been observed, or observed only as a rare event, in hybrid catfish as much as 14 weeks post challenge. It is thought the hybrid catfish is a dead end host in the H. ictaluri life cycle. This supports field observations that suggest incidence and prevalence of PGD in hybrid production ponds is less than observed in channel production systems. Comparative pond studies have demonstrated H. ictaluri densities in hybrid catfish ponds are less than channel catfish ponds managed under similar conditions after only two years of production. Similar work is ongoing comparing relative susceptibility of channel, blue and hybrid catfish to several Edwarsdiella spp. formerly classified as E. tarda. Our work has demonstrated E. piscicida is more pathogenic to catfish than E. tarda or E. anguillarum, while hybrid and blue catfish are more susceptible to E. piscicida than channels. This is in line with anecdotal reports from industry that suggest E. piscicida is of greater concern in hybrids than channels. Research conducted under the previous project "Development of approaches to prevent and ameliorate diseases of catfish" led to the development of an oral live attenuated vaccine for control of enteric septicemia of catfish and a mechanized system for oral delivery. Continuation of this work under the current project focuses on refinement and validation of the delivery system, development of protocols for the commercial scale production and processing of vaccine serials, identification of factors potentially affecting vaccine safety and efficacy, genetic characterization of the vaccine isolate and development of a molecular based diagnostic assay to differentiate between the attenuated vaccine and wild type E. ictaluri isolate. In collaboration with Mississippi State University Department of Agricultural and Biological Engineering the mechanized delivery system has been refined and validated in field use. In collaboration with the United States Department of Agriculture (USDA), Agricultural Research Service (ARS), National Biological Control Laboratory (NBCL), Stoneville, MS, fermentation and processing procedures for commercial scale vaccine production have been developed. Supporting work demonstrated the vaccine is effective against different E. ictaluri isolates collected between 1999 and 2016 from different geographic regions and low oxygen stress was not shown influence vaccine safety or efficacy. In 2016, over 100 million fingerlings were vaccinated on 6 commercial operations. Data is being used to conduct time-in-motion studies to determine resources needed for commercial application.

Publications

  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Griffin MJ, Reichley SR, GreenwayTE, Quiniou SM, Ware C, GAO DX Gaunt PS, Yanong RPE, Pouder DB, Hawke JP, Soto E. 2015. Comparison of Edwardsiella ictaluri isolates from different hosts and geographic origins. Journal of Fish Diseases doi:10.1111/jfd.12431.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Mischke, C. C., M. J. Griffin, D. J. Wise, T. E. Greenway. 2015. Effects of co-stocking smallmouth buffalo Ictiobus bubalus with channel catfish Ictalurus punctatus. Journal of the World Aquaculture Society. 47:212-219
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Mischke, C.C., C.S. Tucker, D.J. Wise and T.W. Brown. 2015 DEET (N, N?diethyl?m?toluamide) Toxicity to Channel Catfish, Ictalurus punctatus, Sac Fry. Journal of the World Aquaculture Society 46:344-347.
  • Type: Other Status: Published Year Published: 2015 Citation: Reichley, S. R., G. C. Waldbieser, M. Ucko, A. Colorni, L. Dubytska, R. L. Thune, M. L. Lawrence and M. J. Griffin. 2015. Complete genome sequence of an Edwardsiella piscicida-like species isolated from diseased grouper in Israel. Genome Announcements 3(4):e00829-15. doi: 10.1128/genomeA. 00829-15.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Scott, S. J., M. J. Griffin, L. Khoo, and T. K. Bollinger. 2015. Myxobolus neurophilus: a common myxosporidian parasite infecting yellow perch (Perca flavescens) in Saskatchewan, Canada. Journal of Fish Diseases. 38: 355-364.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Alberson, N. R., T. G. Rosser, M. J. Griffin, L. M. Pote, S. K. Buddenborg, E. S. Loker, L. H. Khoo, T. D. Richardson and E. T. Woodyard. A new snail host identified for Drepanocephalus spathans (Digenea: Echinostomatidae) in catfish aquaculture. In proceedings of the 40th Eastern Fish Health Workshop. Charleston, SC. March 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Gaunt PS, Pechan T, Epperson B, Hanon L, Chatla K. 2015. Project Director Meeting for theUSDA National Institute of Food and Agriculture Programs related to Animal Health and Disease. Agriculture and Food Research Initiative Animal Health and Disease/Animal Wellbeing Pathiophysiologic assessment of visceral toxicosis of catfish: management using optimized botulinum detection and risk factor analysis Chicago, IL December 4, 2015
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Griffin, M., C. Ware, C. Mischke, L. Hanson, T. Greenway, T. Byars and D. Wise. Biotic and abiotic factors associated with outbreaks of an emergent strain of Aeromonas hydrophila in catfish aquaculture. In proceedings of the 40th Eastern Fish Health Workshop. Charleston, SC. March 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Griffin, M., C. Ware, S. Quiniou, R. Yanong, D. Pouder, J. Hawke, and E. Soto. Repetitive sequence mediated PCR and gyrB sequence demonstrates intraspecific genetic variability amongst Edwardsiella ictaluri isolates from different hosts and geographic regions. In proceedings of the 40th Eastern Fish Health Workshop. Charleston, SC. March 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Reichley, S.R., M. J. Griffin, C. Ware, G. C. Waldbieser, H. C. Tekedar, M. M. Banes, T. E. Greenway, L. H. Khoo, M. L. Lawrence, D. J. Wise. Recent advancements in our knowledge of Edwarsiella piscicida and E. tarda. In proceedings of the 40th Eastern Fish Health Workshop. Charleston, SC. March 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Rosser, T. G., M. J. Griffin, L. M. Pote, L. H. Khoo, S. M. A. Quiniou, D. J. Wise, T. E. Greenway, N. R. Alberson and S. R. Reichley. An overview of myxozoan parasites associated with catfsih aquaculture. In proceedings of the 40th Eastern Fish Health Workshop. Charleston, SC. March 2015.
  • Type: Other Status: Published Year Published: 2015 Citation: Gaunt PS (2015) Impact of the Veterinary Feed Directive Rule on medicated feeds in aquaculture. The Catfish Journal 27(5) 9,15.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: Gaunt P, Gao D, Gieseker C, Hawke J, Miller R. 2015. Use of minimal inhibitory concentration and disk diffusion zone data to determine epidemiological cutoff values of antimicrobials agents against Edwardsiella ictaluri. Eastern Fish Health Workshop, Charleston, South Carolina, Mar 2-6, 2015


Progress 10/01/14 to 09/30/15

Outputs
Target Audience:The goal of research in this project is to address high priority, industry-identified issues to increase production efficiencies and profitability of aquaculture in the southeastern United States. The target audience for new information and technologies developed from the project will be the U.S. catfish farmer, research scientists, extension specialists, and fish health professionals. Ultimately, American consumers will be the major beneficiaries through the production of an inexpensive, safe, domestically produced seafood product that will help offset the large U.S. trade deficit in seafood commodities. Information derived from this project will be passed to user groups through a formal network of extension program specialists utilizing workshops, seminars, advisory groups, and demonstration projects involving farmer user-groups. Investigators will also deliver findings to other scientist and students of aquaculture through scientific publications and professional meetings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During this reporting period twograduate students on this project weretrained in DNA isolation,PCR analysis, genomesequencing, bioinformatics, fish necropsy, experimental design,aseptic microbiological techniquesand presented their findings atregional,national and international scientific meetings. How have the results been disseminated to communities of interest?Information generated from this project will benefit catfish farmers in the southeastern United States as well as aquaculture research scientists, extension specialists, and fish health professionals. This project will form the framework for the development of integrated fish health management practices that reflect herd health management programs that have been successful in monitoring and controlling diseases in other species of production animals. The project objectives were developed in consultation with the National Warmwater Aquaculture Center Industry Liaison Council and the National Warmwater Aquaculture Center Fish Health Advisory Committee. Information generated from this project has been disseminated to U. S. catfish farmers, fish health specialists and other research scientists through on-farm demonstration projects, scientific journal articles, extension workshops and consultation with farmers. What do you plan to do during the next reporting period to accomplish the goals?Scientists will continue to monitor disease prevalence trends using the diagnostic case submissions to help guide the research needs. This would include changes in currently known diseases as well as possible new emerging diseases. Additional in vitro tests will be conducted to evaluate MIC testing methods for catfish bacterial pathogens. Vaccine research will include expansion of commercial field trials, production of a vaccine delivery system with greater capacity, assessment of cross reactivity of the vaccine isolate to closely related Edwardsiella species, and evaluation of antigenic variation in E. ictaluri field isolates recovered from distinct geographic regions. Pond management strategies will focus on the use of hybrid catfish as a means reducing pathogen loading rates in catfish production systems and use of multiplex PCR assays to assess treatment efficacies and monitor pathogen loading rates in commercial catfish production systems.

Impacts
What was accomplished under these goals? This project addresses practical, production-oriented problems, identified by industry advisory groups, through research derived management programs designed to improve fish health and production efficiencies. The first objective focuses on new, emerging disease and the development of rapid diagnostic procedures for important catfish pathogens. This approach will utilize diagnostic records to monitor disease trends occurring in the channel, blue and channel x blue hybrid catfish. The second objective addresses the development of molecular-based diagnostics that will aide in disease surveillance programs evaluating the epidemiology and treatment efficacies of important catfish pathogens. The third objective will investigate responses of catfish to therapeutic agents and oral vaccines. The fourth objective will evaluate novel management strategies to improve fish health and production. Successful completion of this project will assist U.S. catfish farming by improving production efficiencies through the development and implementation of improved fish health management practices. Objective 1: Investigate new and emerging diseases, and develop rapid diagnostic procedures for important pathogens of channel, hybrids and blue catfish. Diagnostic records provide critical insight to changes in disease trends and emergence of new diseases affecting animal production systems, and is an essential component of population health management. The Aquatic Research and Diagnostic Laboratory (ARDL) provided diagnostic services to producers in the southeastern United States and diagnostic support for on-going disease and production research. In 2014 the ARDL processed 701 case submissions involving, bacterial, viral, parasitic and histopathological evaluations. In addition, 634 water samples were also analyzed. Results were archived in a retrievable database and an end-of year report generated electronically on the Thad Cochran National Warmwater Aquacutlure Center website (http://tcnwac.msstate.edu). In support of diagnostic research, multiplex quantitative polymerase chain reactions assays were developed for predominant fish pathogens effecting commercial catfish culture. These protocols allow for the simultaneous quantification and detection of multiple fish pathogens from environmental and tissue samples. Multiplex qPCR assays are being used by research scientists in on-going disease monitoring projects aimed at developing and evaluating disease management strategies and to aide in diagnostic evaluations. Clinical research demonstrated acted synergistically with F. columnare infection to cause increased mortality in catfish thatn exposure to either botulinum or F. columnare alone. This information is used by farmers, research scientists, and fish health specialists to identify emerging diseases and develop and evaluate disease treatments. Objective 2: Study the pathology and epidemiology of significant pathogens affecting cultured catfish. Trematode infections have become a serious problem in commercially raised catfish. Laboratory submissions indicate that Bolbophorus damnificus continues to remain and important parasitic disease with 4.7% of cases submitted to the laboratory in 2014. This may be a function of pelicans remaining longer in the area then previous years, as well as an increase in potential loafing areas. In addition, a new species of trematode, Drepanocephalus auritus has been shown to cause mortality in juvenile channel catfish under experimental conditions. In laboratory trials the parasite was shown to localize in the branchial arches and obstruct blood flow to the gills. Additional work also indicates that the lateral line system is also a predilection site for the parasite. Fortunately, the infection was not shown to persist in the catfish beyond the acute stages of infection, indicating the potential for recovery if removed from the source of infection. In young fish, mechanical occlusion of the branchial vessels by the parasite can result acute losses and D. auritus is now recognized as a potential pathogen of catfish by fish health specialist and diagnosticians. As a result of this work, young fish with unexplained losses are now being evaluated for this disease. Research done in collaboration with MSU CVM in Starkville, MS has identified a new snail host for both Bolbophorus damnificus and Drepanocephalus auritus. Snails in the Biomphalaria havanensis/obstructa complex have been found in increasing numbers in catfish production ponds in East Mississippi. Under experimental conditions, Biomphalria spp. snails collected from these ponds were demonstrated to transmit the infective stages of both B. damnificus and D. auritus to juvenile channel catfish. This work identifies a second snail host capable of transmitting these parasites in commercial catfish ponds. Previously, Biompharia spp. snails have been considered a pest of minimal concern on catfish operations, although this research demonstrates that producers should be wary of their presence and take appropriate action if large populations of these snails are habitually found in ponds. Objective 3: Investigate the responses of channel, hybrid and blue catfish to therapeutic agents and oral vaccines for important bacterial pathogens. Antimicrobial susceptibilities of catfish pathogen Edwardsiella ictaluri was determined by three independent laboratories. Frequency distribution of minimal inhibitory concentration (MIC) values was used to set epidemiologic breakpoints. These values will be used to discriminate between wild-type (i.e. originally susceptible bacterial populations) from non-wild type (i.e. populations with acquired and mutational resistance mechanism) isolates and help determine susceptibility of bacteria to antimicrobials. Data has been submitted to the Veterinary Antimicrobial Susceptibility Testing (VAST) subcommittee for evaluation and determination of quality control ranges by the Clinical Laboratory Standards Institute (CLSI). Once the quality control ranges are accepted by the VAST, data will be published in the CLSI VET05-A2 guideline in 2016. This data will be used in clinical evaluations and to determining effective recommendations for control of bacterial infections in catfish. Objective 4: Develop and implement practical management strategies to improve fish health and production efficiency. Enteric septicemia of catfish (ESC) is a bacterial diseases with an economic impact of $30 million annually. Research generated from this project has led to the development of an oral vaccination platform that provides exceptional protection against ESC. Protocols for commercial scale vaccine production and a mechanized system for mixing the vaccine with feed at the point of delivery were developed and validated. In support of vaccine development (objective 3 of this project), the effects of fish age and stress on vaccine safety and efficacy were determined. Data indicated fish can be safely vaccinated at 30 days of age and extreme low oxygen events before or after oral immunization does compromise vaccine safety and efficacy. Field trials were conducted using the experimental vaccine and delivery system showing a 2 fold increase in the per acre value of production. This work is being conducted in support of the USDA/APHIS licensing process for the commercial use of biologics. A commercially available effective vaccine will greatly increase the profitability of commercial catfish culture.

Publications

  • Type: Book Chapters Status: Published Year Published: 2014 Citation: Miller R., J. Carson, I. Dalsgaard, P. Gaunt, C. Gieseker, J. Hawke, R. Reimschuessel, P. Smith, T. Somsiri, and C.C.Wu. Methods for Broth Dilution Susceptibility Testing of Bacteria Isolated From Aquatic Animals; Approved Guideline-Second Edition. CLSI document VET04-A2. Wayne, PA: Clinical and Laboratory Standards Institute; 2014.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Allen, P.J., D.J. Wise, T.E. Greenway, L. Khoo, M.J. Griffin, and M. Jablonsky. 2014. Using 1-D 1H and 2-D 1H J-resolved NMR metabolomics to understand the effects of anemia in channel catfish (Ictalurus punctatus). Metabolomics. doi: 10.1007/s11306-014-0767-2
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Banajee, K. P.S. Gaunt, L. Khoo and S.D. Gaunt SD. 2014. Pathology in Practice. Journal of American Veterinary Medical Association 246 (11):1193-1195.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Beecham R., T. Thomas, D. Gao, and P.S. Gaunt. 2014. The effects of a sublethal dose of botulinum serotype E on the swimming performance of channel cat?sh fingerlings. Journal of Aquatic Animal Health 26(3):149153.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Camus C.C., D.J. Wise, L.H. Khoo, J. Shi, and R.D. Berghaus. 2014. Iron status of channel catfish Ictalurus punctatus affected by channel catfish anemia and response to parenteral iron. Diseases of Aquatic Organisms. 107(3):241-248.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Chatla K., P. Gaunt, L. Petrie-Hanson, C. Hohn, L. Ford, and L. Hanson. 2014. Zebrafish (Danio rerio) bioassay for visceral toxicosis of catfish and botulinum neurotoxin serotype E Journal of Veterinary Diagnostic Investigation 2014, Vol. 26(2) 240245.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Chou, L., M.J. Griffin, T. Fraites, C. Ware, H. Ferguson, N. Keirstead, J. Brake, J. Wiles, J.P. Hawke, M. T. Kearney, R.G. Getchell, P. Gaunt, E. Soto. 2014. Phenotypic and genotypic heterogeneity amongst Streptococcus iniae isolates recovered from cultured and wild fish in North America, Central America and the Caribbean islands. Journal of Aquatic Animal Health 26: 263-271.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Gaunt P, N. Chatakondi, D. Gao, and R. Endris. 2015. The efficacy of florfenicol for control of mortality associated with Edwardsiella ictaluri in three species of catfish. Journal of Aquatic Animal Health Journal of Aquatic Animal Health 27:4549.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Griffin M.J., S.R. Reichley, L.H. Khoo, C. Ware, T.E. Greenway, C.C. Mischke, and D.J. Wise. 2014. Comparative susceptibility of channel catfish, blue catfish, and their hybrid cross to experimental challenge with Bolbophorus damnificus (Digenea: Bolbophoridae) cercariae. Journal of Aquatic Animal Health. 26(2): 96-99.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Griffin M.J., S. Quiniou, C. Ware, L. Bogdanovic, and E. Soto. 2014. Kudoa thunni from blackfin tuna (Thunnus atlanticus) harvested off the island of St. Kitts, West Indies. Journal of Parasitology. 100 (1): 110-116.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Griffin M.J., C. Ware, S. Quiniou, J. Steadman, P. Gaunt, L. Khoo, and E. Soto. 2014. Edwardsiella piscicida identified in the southeastern United States by gyrB sequence, species-specific and repetitive sequence mediated PCR. Diseases of Aquatic Organisms. 108(1): 23-35.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Griffin, M.J., L.H. Khoo, J.M. Steadman, C. Ware, S.M. Quiniou, C. C. Mischke, T.E. Greenway and D.J. Wise. 2014. Chronic pathology and longevity of Drepanocephalus spathans infections in juvenile channel catfish. Journal of Aquatic Animal Health. 26: 210-218.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Keirstead N.D., J.W. Brake, M.J. Griffin, I. Halliday-Simmonds, M.A. Thrall, and E. Soto. 2014. Fatal septicemia caused by the zoonotic bacterium Streptococcus iniae during an outbreak in Caribbean reef fish. Veterinary Pathology 51:1035-1041.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Khoo, L., F. Austin, S. Quiniou, P. Gaunt, D. Riecke, A. Jacobs, K. Meals, A. Dunn and M. Griffin. 2014. Lactococcosis in silver carp Hypophthalmichthys molitrix. Journal of Aquatic Animal Health. 26: 1-8.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Leach C.A., M.S.Thomas, A.J.Cooley, G.C. Waldbieser, B.G. Bosworth, E.L. Torrans, and L.H. Khoo. 2014. Histological and computed tomographic evaluation of a parasitic conjoined twin in hybrid catfish (Ictalurus punctatus {Rafinesque] X Ictalurus furcatus [Lesueur]). Journal of Fish Diseases, 37(6):521-626.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Mischke, C.C., D.J. Wise, M.J. Griffin and T.E. Greenway. 2014. Potassium permanganate is not an effective pond disinfectant to control Dero digitata. Journal of World Aquaculture Society. 45: 350-353.
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Peterson, B.C., C. Flora, M.W. Woods, B.G. Bosworth, S.M. Quiniou, T.E. Greenway, T.S. Byars, and D.J. Wise. (Accepted). Vaccination of full-fib channel catfish families against enteric septicemia of catfish with an oral live attenuated Edwardsiella ictaluri vaccine. Journal of Aquatic Animal Health.
  • Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Pinto, H.A., M.J. Griffin, S.M. Quiniou, C. Ware, and A.L. de Melo. 2015. Biomphalaria straminea (Mollusca: Planorbidae) as an intermediate host of Drepanocephalus (Trematoda: Echinostomatidae) in Brazil: a morphological and molecular study. Parasitology Research. DOI 10.1007/s00436-015-4469-0.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Rosser T.G., M.J. Griffin, S.M.A. Quiniou, L,H, Khoo, and LM Pote. 2014. 18S rRNA gene sequencing identifies a novel species of Henneguya parasitizing the gills of the channel catfish (Ictaluridae). Parasitology Research 113(12): 4651-4658.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Rosser T.G., M.J. Griffin, S.M. Quiniou, T.E. Greenway, L.H. Khoo, D.J..Wise, and L.M. Pote. 2014. Molecular and morphological characterization of myxozoan actinospore types from a commercial catfish pond in the Mississippi Delta. Journal of Parasitology. 100:828-839.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Rosser T.G., M.J. Griffin, S.M. Quiniou, L.H. Khoo, T.E. Greenway, D.J. Wise, and L.M. Pote. 2015. Small subunit ribosomal RNA sequence links the myxospore stage of Henneguya mississippiensis n. sp. from channel catfish Ictalurus punctatus to an actinospore released by the benthic oligochaete Dero digitata. Parasitology research, 114(4), 1595-1602.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Scott, S.J., M.J. Griffin, L. Khoo, and T.K. Bollinger. 2015. Myxobolus neurophilus: a common myxosporidian parasite infecting yellow perch (Perca flavescens) in Saskatchewan, Canada. Journal of Fish Diseases. 38: 355-364.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Wolf J.C., W.A.Baumgartner, V.S. Blazer, A.C. Camus, J.A. Engelhardt, J.W. Fournie, S. Frasca Jr, D.B. Groman, M.L. Kent, L. H. Khoo, J.M. Law, E.D. Lombardini, C Ruehl-Fehlert, H.E.Segner, S.A. Smith, J.M. Spitbergen, K. Weber, and M.J. Wolfe MJ. 2015. Nonlesions, misdiagnoses, missed diagnoses, and other interpretive challenges in fish histopathology studies - A Guide for investigators, Authors, reviewers, and readers. Toxicologic Pathology 43(3)297-325.
  • Type: Book Chapters Status: Published Year Published: 2014 Citation: Hanson, L.A., M.R. Liles, M.J. Hossain, M.J. Griffin and W.G. Hemstreet. 2014. Motile Aeromonas septicemia. In AFS-FHS (American Fisheries Society-Fish Health Section). FHS blue book: suggested procedures for the detection and identification of certain finfish and shellfish pathogens, 2014 edition. Accessible at: http://afs-fhs.org/bluebook/bluebook-index.php.
  • Type: Theses/Dissertations Status: Published Year Published: 2014 Citation: Chatla, K. 2014. Botulinum associated with visceral toxicosis of catfish: Investigation of a viral-vectored heavy chain subunit vaccine and development of a zebrafish bioassay. Available through: http://sun.library.msstate.edu/ETD-db/ETD-browse/browse.
  • Type: Book Chapters Status: Published Year Published: 2015 Citation: Soto, E., M.J. Griffin, and J.A. Tobar. 2015. Mucosal vaccines. In Mucosal Health in Aquaculture, ed. Beck B., Peatman E. Elsevier, Oxford, UK.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Reichley, S.R., G.C. Waldbieser, M.L. Lawrence, M.J. Griffin. 2015. Complete genome sequence of an Edwardsiella piscicida-like species recovered from tilapia in the United States. Genome Announcements 3(5):e01004-15. doi:10.1128/genomeA.01004-15.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Wise, D. J., T. E. Greenway, T. S. Byars, M. J. Griffin and L. H. Khoo. 2015. Oral vaccination of channel catfish against enteric septicemia of catfish (ESC) using a live attenuated Edwardsiella ictaluri isolate. Journal of Aquatic Animal Health. 27: 135-143.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Reichley, S.R., G.C. Waldbieser, H.C. Tekedar, M.L. Lawrence and M.J. Griffin (2015). Complete genome sequence of Edwardsiella tarda isolate FL95-01, recovered from channel catfish. Genome Announcements 3(3):e00682-15. doi: 10.1128/genomeA.00682-15.
  • Type: Journal Articles Status: Published Year Published: 2015 Citation: Reichley, S.R., C. Ware, T.E. Greenway, D.J. Wise and M.J. Griffin. (2015). Real-time PCR assays for detection and quantification of Edwardsiella tarda, Edwardsiella piscicida, and Edwardsiella piscicida-like sp. in catfish tissues and pond water. Journal of Veterinary Diagnostic Investigation. 27: 130-139.
  • Type: Journal Articles Status: Published Year Published: 2014 Citation: Rosser, T.G., M.J. Griffin, S.M. Quiniou, T.E. Greenway, L.H. Khoo, D.J. Wise, and L.M Pote. 2014. Molecular and morphological characterization of myxozoan actinospore types from a commercial catfish pond in the Mississippi Delta. Journal of Parasitology 100: 828-839.
  • Type: Book Chapters Status: Published Year Published: 2014 Citation: Miller R., J. Carson, I. Dalsgaard, P. Gaunt, C. Gieseker, J. Hawke, R. Reimschuessel, P. Smith, T. Somsiri, and C.C.Wu. CLSI Performance Standards for Antimicrobial Susceptibility Testing of Bacteria Isolated From Aquatic Animals; Second Informational Supplement. CLSI document VET03/VET04-S2. Wayne, PA: Clinical and Laboratory Standards Institute; 2014.


Progress 09/09/14 to 09/30/14

Outputs
Target Audience: Research in the area of fish health management and diagnostic medicine will establish new effective measures for the early detection, prevention, and treatment of disease. Reducing disease-related costs will substantially increase the net profitability of fish farming and help to insure the economic viability of the channel catfish industry. This project will form the framework for the development of integrated fish health management practices that reflect herd health management programs that have been successful in monitoring and controlling diseases in other species of production animals. Information generated from this project will benefit catfish farmers in the southeastern United States as well as aquaculture research scientists, extension specialists, and fish health professionals. Ultimately, American consumers will be the major beneficiaries through the production of an inexpensive, safe, domestically produced seafood product that will help offset the large U.S. trade deficit in seafood commodities. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Information obtained from the project, in conjunction with hands-on diagnostic training, is used to provide experience for veterinary students during their food animal rotation. This experience is offered to all veterinary students at Mississippi State University and externs from other veterinary programs. How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? A virulent form ofAeromonas hydrophila (VAh) has been identified as an emerging disease in commercially raised catfish. Losses associated with VAh range from low-grade chronic to catastrophic. The prevalence and persistence of VAh will be determined from infected and non-infected populations of commercially raised catfish. Initial samples have been collected and serum samples from resident fishhave been processed for determination of anti-A. hydrophilaantibody levels. In addition,fecal, tissue, water and sediment samples have been processed for detection ofA. hydrophilaby qPCR analysis. The Biolog Microplate system consisting of 94 biochemical tests will be used to characterize the virulent strain of Aeromonas hydrophila. Additional samples will be collected monthly from test sites over a period of12 months. Other projects included ESC field vaccination trials, the prevalence ofmyxozoan infections in commercially raised channel and hybrid catfish, development of rapid diagnostic tests for the detection of fish pathogens in fish tissues and environmental samples, evaluation of antibiotic resistance in bacterial pathogens recovered from diagnostic case submissions, and development of best management practices for the control of bacterial and parasitic infections affecting channel and hybrid catfish. These projects have been initiated but there is no progress to report at this time.

Publications