碩士 / 國立成功大學 / 生物科技研究所碩博士班 / 90 / Pasteurellosis or pseudotuberculosis caused by the organism formerly known as Pasteurella piscicida, has been reclassified as Photobacterium damselae subsp. piscicida according to 16S rRNA gene sequence comparisons and chromosomal DNA-DNA hybridization data. Pasteurellosis is one of the main bacterial diseases lethal to many fish. In Taiwan, it is a common bacterial disease in cobia aquaculture, and it usually causes more than 30% mortality. People have been using chemotherapeutic agents extensively to eliminate infections; however, this also brought infections caused by drug-resistant pathogens into cultured fish. For this reason, immune-prophylaxis has become the best way for controlling the disease.
A number of studies examined the effectiveness of vaccination as a preventive mean against pasteurellosis. The majority of the vaccines being tested contained formalin-killed bacteria, but it didn’t give a satisfactory result. Some other studies showed that an addition of extracellular products in killed vaccines tends to give higher protection level than killed vaccines. Unknown components in extracellular products which increase the protection level of killed vaccines worth further investigation.
In this experiment, whole cell bacterin and its extracellular products were harvested first, and then four probes, rabbit anti-Ph.d.p serum(inoculated killed bacteria), cobia anti-Ph.d.p serum(inoculated killed bacteria), cobia anti-Ph.d.p serum(survival after challenge with Ph.d.p), and cobia serum(pre-inoculated Ph.d.p) were used for western blot analysis.
According to the results of western blotting of ECP, all sets of cobia serum can interact with 53 kD. The western blotting of cell bacterin showed that Cobia anti-Ph.d.p serum had a major band in 49.8 kD; therefore, 49.8 kD antigenic substance could possibly be used as an indicator of successful vaccination. Furthermore, the cobia anti-Ph.d.p antiserum and rabbit anti-Ph.d.p antiserum can interact with a 39kD protein. This experiment was performed based on antigenic substances screened from genomic DNA library published by Hirono et al in 1997. The gene of interest was cloned in order to express the antigenic substances; however, the expressed antigenic substance only interacted weakly with rabbit anti-Ph.d.p antiserum and cobia anti-Ph.d.p antiserum. For this reason, this antigenic substance is not suitable for vaccine development maybe due to its poor antigenity. To confirm the inference metioned above, further animal experiments should be performed.
| Identifer | oai:union.ndltd.org:TW/090NCKU5111007 |
| Date | January 2002 |
| Creators | Hui-En Chen, 陳惠恩 |
| Contributors | Hui-Lang Yang, 楊惠郎 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 67 |
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