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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Study in the Propagation Conditions for Vibriophages £pVP and £pVA

Chiu, Chi-Wen 26 July 2010 (has links)
Seventeen strains of multi drug-resistant strains were isolated from aquaculture farms in previous study, and 82% (14/17) of these strains are belong to Vibrio species, which is one of the major pathogens in the aquaculture farms. Vibrio disease (vibriosis) which caused by the Vibrio will cause the fish skin ulcer with bleeding and gastrointestinal symptoms such as swelling. The highest mortality rate of Vibrio infected marine fish is up to 100%. Two vibriophages, Vibrio parahaemolyticus vibriophage £pVP2 and Vibrio alginolyticus vibriophage £pVA2, were isolated from aquaculture environments in this study. The morphology of vibriophage was examined by electron microscopy. The £pVP2 phage has an oval head with a tail and six tail fibers. As £pVA2, an icosarhedral head with an short tail is observed. In the DNA electrophoresis analysis, a fragment at 17.8k bp was observed in both £pVA2 and £pVP2 sample. Restriction endonuclease digestion pattern revealed that the £pVA2 vibriophage DNA can be cut into various small size of DNA fragments by EcoR I and Xba I endonuclease. In the host-range analysis, £pVP2 can infect Vibrio parahaemolyticus and Vibrio alginolyticus, while £pVA2 and £pVP2 cannot infect other Vibrio spp., Pasteurella, E. Coli, and antibiotic-resistant bacteria isolated from aquaculture farms. £pVA2 and £pVP2 can survive at the temperature below 65¢XC and 63¢XC, respectively. To obtain the maximum proliferation of vibriophage, different conditions were tested, including infection time point, host bacteria age, MOI (multiplicity of infection) and various mediums. Vibriophage £pVA2 was proliferated under following conditions: (1) phage was add to the medium with host seed together; (2) the overnight cultured host bacteria was used as seed; (3) the host cells were infected at MOI= 10-6; (4) MSWYE media was used as culture media. Vibriophage £pVP2 was proliferated following £pVA2 conditions but MOI values was 10-4.

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