Study in the Propagation Conditions for Vibriophages φVP and φVA

• Main Authors: Chi-Wen Chiu, 邱娸雯
• Other Authors: Chan-Shing Lin
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/19337695963173505251

碩士 === 國立中山大學 === 海洋生物科技暨資源學系研究所 === 98 === 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 φVP2 and Vibrio alginolyticus vibriophage φVA2, were isolated from aquaculture environments in this study. The morphology of vibriophage was examined by electron microscopy. The φVP2 phage has an oval head with a tail and six tail fibers. As φVA2, an icosarhedral head with an short tail is observed. In the DNA electrophoresis analysis, a fragment at 17.8k bp was observed in both φVA2 and φVP2 sample. Restriction endonuclease digestion pattern revealed that the φVA2 vibriophage DNA can be cut into various small size of DNA fragments by EcoR I and Xba I endonuclease. In the host-range analysis, φVP2 can infect Vibrio parahaemolyticus and Vibrio alginolyticus, while φVA2 and φVP2 cannot infect other Vibrio spp., Pasteurella, E. Coli, and antibiotic-resistant bacteria isolated from aquaculture farms. φVA2 and φVP2 can survive at the temperature below 65°C and 63°C, 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 φVA2 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 φVP2 was proliferated following φVA2 conditions but MOI values was 10-4.