Progress 09/01/18 to 08/31/21
Outputs
Target Audience:The target audiences are fish health researchers, veterinarians, microbiologists and catfish producers. -Efforts Science-based knowledge has been delivered in laboratory teaching and group meetings Changes/Problems:Mutant construction in A. hydrophila has been challenging. However, we accomplished our first goal by producing more than 20 A. hydrophila mutants. We noticed a high variation in fish mortality among biological replicates during fish challenges. This variation was reduced by increasing the number of replicate tanks. What opportunities for training and professional development has the project provided?This project has provided training and professional development opportunities for one doctoral student, and one postdoctoral scientist. How have the results been disseminated to communities of interest? The doctoral student has given a college-wide seminar. The doctoral student has attended a conference and given a seminar. What do you plan to do during the next reporting period to accomplish the goals?Although the project has ended, efficacy of the three attenuated mutants and the new double gene deletion mutant is being re-evaluated.
Impacts
What was accomplished under these goals?
-Goal one Two new A. hydrophila mutants were constructed, bringing the total number of mutant strains to 24. These genes had roles in T6SS, sec pathway, tat pathway, ATP binding, flagella, lipopolysaccharide assembly, and type IV toxin-antitoxin system. -Goal two Safety and efficacy of 24 A. hydrophila mutants were assessed. 2) Specific objectives met -Goal one Two new A. hydrophila mutants were constructed. -Goal two Safety of 24 A. hydrophila mutants was assessed Efficacy of three attenuated A. hydrophila mutants was assessed. 3) Significant Results Achieved -Goal one Two new A. hydrophila mutants were constructed. -Goal two Safety of 24 A. hydrophila mutants was assessed in catfish Results indicated that three mutants were attenuated compared to A. hydrophila wild type. Efficacy of the three attenuated A. hydrophila mutants was assessed in catfish. One of the attenuated strains provided 55.5% relative percent survival. The other two attenuated mutants caused catfish mortalities during vaccination. Thus, we constructed a new double gene deletion mutant to reduce virulence further. Safety and efficacy of A. hydrophila mutants were challenging due to high tank-to-tank variation. To reduce variation, we increased the number of replicate tanks to six. Efficacy of the three attenuated mutants and the new double gene deletion mutant is being re-evaluated. 4) Key outcomes or other accomplishments realized -Goal one Two new A. hydrophila mutants were constructed. -Goal two Mutants showed varying degrees of attenuation in catfish fingerlings. Safety of 24 A. hydrophila mutants was assessed in catfish The majority of mutants were not safe. Efficacy of the three attenuated A. hydrophila mutants was assessed in catfish. One mutant showed complete attenuation and 55.5% relative percent survival. The other two attenuated mutants caused catfish mortalities during vaccination. Thus, a new double gene deletion mutant was constructed to reduce virulence further. A. hydrophila challenges show high tank-to-tank variation. Increasing the number of replicate tanks reduces this variation. Efficacy of the three attenuated mutants and the new double gene deletion mutant is being re-evaluated.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2021
Citation:
Ozdemir E, Abdelhamed H, Ozdemir O, Wu R, Lawrence M, Karsi A. 2021. Development of live attenuated Aeromonas hydrophila vaccine candidates. 2021 CRWAD Meeting. Chicago, IL, USA.
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Progress 09/01/19 to 08/31/20
Outputs
Target Audience:The target audience is fish health researchers, veterinarians, microbiologists, and catfish producers. Science-based knowledge has been delivered in laboratory teaching and group meetings. Changes/Problems:Mutant construction in A. hydrophila has been challenging. However, we were able to accomplish our first goal by producing more than 20 in-frame deletion mutants. During fish challenges, we noticed a high variation in fish mortality among biological replicates. We plan to overcome this variation by increasing the number of biological replicates from four to six or eight per treatment. What opportunities for training and professional development has the project provided?This project has provided training and professional development opportunities for one doctoral student, one postdoctoral scientist, and one visiting scientist. How have the results been disseminated to communities of interest?The doctoral student has given a college-wide seminar. What do you plan to do during the next reporting period to accomplish the goals? Verify safety and efficacy of mutants in catfish fingerlings Determine tissue persistence of safe strains Determine pathological changes after vaccination Assess suitability of safe strains for fry vaccination
Impacts
What was accomplished under these goals?
1) Major activities completed -Goal one New A. hydrophila mutants were constructed. -Goal two Safety and efficacy of A. hydrophila mutants were assessed. 2) Specific objectives met -Goal one Eight new A. hydrophila mutants were constructed. -Goal two Safety of twenty-two A. hydrophila mutants was assessed Efficacy of one attenuated A. hydrophila mutant was assessed. 3) Significant Results Achieved -Goal one Eight new A. hydrophila mutants have been constructed. -Goal two Safety of twenty-two A. hydrophila mutants was assessed Efficacy of one attenuated A. hydrophila mutant was assessed. 4) Key outcomes or other accomplishments realized -Goal one Twenty-two A. hydrophila mutants were constructed. -Goal two Mutants showed varying degrees of attenuation in catfish fingerlings. The majority of mutants were not safe. One mutant showed complete attenuation and some efficacy.
Publications
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Progress 09/01/18 to 08/31/19
Outputs
Target Audience:Target Audiences for this project include: Fish health research community Veterinarians Catfish producers Microbiologists -Efforts Science-based knowledge has been delivered in laboratory teaching and fish health-related courses. Changes/Problems: Mutant construction in A. hydrophila has been challenging. However, we expect to overcome this by designing new primers, increasing the number of colony screening after conjugation, and optimizing our protocols. What opportunities for training and professional development has the project provided? This project has provided training and professional development opportunities for one postdoc (Adef Kordon) and one doctoral student (Eda Ozdemir). 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? Finalize the construction of all 20 A. hydrophila mutants. Determine the safety and efficacy of mutants in catfish fingerlings
Impacts
What was accomplished under these goals?
1) Major activities completed -Goal one Construction of 14 A. hydrophila mutants was completed. -Goal two Initial screening of mutants' virulence in catfish fingerlings was assessed. 2) Specific objectives met -Goal one Construction of 14 A. hydrophila mutants was completed. -Goal two Initial screening of mutants' virulence in catfish fingerlings was assessed. 3) Significant Results Achieved We were able to construct 14 in-frame deletion mutants. 4) Key outcomes or other accomplishments realized Mutants showed varying degrees of attenuation in catfish.
Publications
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