碩士 / 國立臺灣大學 / 漁業科學研究所 / 87 / Abstract
Streptococcus infects a wide range of animals, and causes disease in freshwater and marine fish. A number of Streptococcus sp. has been reported to be associated with fish infection. However, Only few Streptococcus spp. have been identified as fish pathogens, other ichthyic-origin Streptococci have not been named . In the study, Pathogenic Streptococci isolated from tilapia, Oreochromis niloticus, ayu, Plecoglossus altivelis,and rainbow trout, Oncorhynchus mykiss, were collected to study their morphological, physiological, biochemical characteristics, and antibiotics susceptibility. Further numerical taxonomy based on these characteristics, and the 16S rDNA sequencing of these isolates were also done.
The morphological, physiological, biochemical characteristics of isolate Trout-51、Trout-53 and 791031-1G derived from rainbow trout, were similar, and tests performed by Rapid 32 Strept system resulted in the similarity of 99.5%、98.7%、99.9% to Lactococcus garvieae in isolates Trout-51、Trout-53 and 791031-1G, separately.
Further study of 16S rDNA sequencing of the three isolates and results revealed all isolates were belonged to Enterococcus seriolicida.
The morphological, physiological, biochemical characteristics of isolate Hualian-2 was derived from tilapia, and tests performed by Rapid ID 32 Strept system resulted in 99.8% similarity to E. faecalis. Further study the 16S rDNA sequencing of the isolates and results revealed it was belonged to E. faecalis.
The morphological, physiological, biochemical characteristics of isolates F229、F238、F266、F360 and Hualian-1 were derived from tilapia , and tests performed by Rapid ID 32 Strept system resulted in the identification of Streptococcus spp. in all 5 isolates. The species of Streptococcus was unable to identify. Further study the 16S rDNA sequencing of three isolates,and resultes revealed all isolates were belonged to Streptococcus parauberis or S. uberis .Further study about the total 16S rDNA sequencing of the isolated will be done to identity their species.
The morphological, physiological, biochemical characteristics of isolate F187 and F192 derived from tilapia, and tests performed by Rapid ID 32 Strept system resulted in 94.5% and 95.2% similarity to Lactococcus lactis cremoris ,separately. Further study the 16S rDNA sequencing of the three isolates, and resultes revealed all isolated were belonged to S. agalactiae.
By comparing the results of Rapid ID32 Strept system to 16S rDNA sequencing, we concluded that the 16S rDNA sequencing method was more reliable to identify Streptococcus to species level.
All isolates were performed phenotypic analysis by using numerical taxonomy method. The resultes indicated that genus Streptococcus and Enterococcus were similar, the similarity level was 85%.
| Identifer | oai:union.ndltd.org:TW/087NTU00451004 |
| Date | January 1999 |
| Creators | Lin, Chun-Wan, 林純婉 |
| Contributors | , 李英周, 張本恆 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 110 |
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