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Title: | 自臺灣養殖淡水魚類分離之鏈球菌的病原性,表現型和基因型分析 The pathogenesis , phenotype and genotype analysis of Streptococcus spp. isolated from cultured freshwater fish in Taiwan |
Authors: | Chun-Wan Lin 林純婉 |
Publication Year : | 1999 |
Degree: | 碩士 |
Abstract: | 鏈球菌的感染是屬於廣泛性的,它不僅會感染人類,也會感染其他動物;對魚類的感染包括海水魚及淡水魚種。目前僅有一些鏈球菌被証明對魚具有病原性,但在這些鏈球菌中有許多尚未被命名。本研究主要是由罹患鏈球菌病之吳郭魚、香魚及虹鱒所分離出來的鏈球菌,進行形態、生理、生化測試及抗生素敏感性試驗,接著將這些生理、生化測試進行數值分類及以聚合酵素連鎖反應,進行 16S rDNA 部分基因序列分析。 由虹鱒所分離出來的菌株有 791031-1G、Trout-51、Trout-53 及 Trout-403,及由香魚所分離出來的菌株為 Ayu-403;其中 791031-1G、Trout-51 與 Trout-53 之形態、生理及生化特徵相似,以 Rapid ID 32 Strept 鑑定,顯示這5個菌株與 Lactococus garvieae 相似性分別為 99.9、99.5、99.7、51.9 及 99.9%;接著取 Trout-51、Trout-403 及 Ayu-403 菌株進行分子鑑定,以聚合酵素連鎖反應進行 16S rDNA 部分基因序列分析,與Enterococcus seriolicida之相似性為 99%。 由吳郭魚所分離出來的菌株 Hualian-2,其形態、生理及生化特徵與標準菌株Enterococcus faecalis ATCC19433 相似;以 Rapid ID 32 Strept 鑑定,與Enterococcus faecalis之相似性為 99.8%;再以聚合酵素連鎖反應進行 16S rDNA 部分基因序列之分析,與Enterococcus faecalis之相似性為 98%。 由吳郭魚所分離出來的菌株 F187 和 F192,其形態、生理及生化特徵相似,並以 Rapid ID 32 Strept 鑑定,與 Lactococcus lactis cremoris之相似性分別為 94.5 及 95.2%,接著取 F187 菌株進行分子鑑定,以聚合酵素連鎖反應之方法,進行 16S rDNA 部分基因序列之分析,與Streptococcus agalactiae之相似性為 98%。 自台灣的東西部養殖吳郭魚所分離出來有 F229、F238、F266、F360 及 Hualian-1 等5菌株其形態、生理及生化特徵相似,以 Rapid ID 32 Strept 鑑定均屬於鏈球菌屬(Strptococcus sp.) ,至於種別則無法鑑定出來。接著取這5株菌進行分子鑑定,以聚合酵素連鎖反應,進行 16S rDNA 部分基因序列之分析,與Streptococcus parauberis之相似性為 95%.但必須再將這5株菌之 16S rDNA 完全基因序列定序出來,才可判斷其種別。 在本實驗中由 Rapid ID 32 Strept 之鑑定結果及 16S rDNA 部分基因序列比較我們認為以 16S rDNA 基因序列之分析法,對於鏈球菌之種別(Species)鑑定最為可靠。 在本實驗中將所有的菌株之物理化學性狀以數值分類之方法進行表現型的分析,結果顯示鏈球菌屬與腸球菌屬之相似性為85%以上。 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%. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/75077 |
Fulltext Rights: | 未授權 |
Appears in Collections: | 漁業科學研究所 |
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