Bacterial Fish Pathogens: Outcome of Molecular Studies for Taxonomy, Epidemiology and Identification

魚類細菌性病原：分類，流行病學及鑑定上之分子研究

Jean-François Bernardet

《Zoological Studies》 35卷2期 (1996/04) Pp. 71-77

摘要

最近三十年分子生物學的方法逐漸被用來研究細菌性病原。運用這些方法可以在基因層次上比較不同細菌品系及種類且可產生許多有意義的資料，這些方法在外類上都各自有特定的準確範圍，因此進行研究時所採用的骨子生物學的方法一定要適合所期望的分類資料的層次。例如：16S rRNA這部分是個很好的分子時鐘，研究這個基因的鹼基序列的方法（如首先用寡核糖核酸分解法，續有DNA/rRNA的雜合反應及DNA鹼基的序列分析）能有效的深入探討細菌之間的關係，因而對以支序圖表示的細菌分類能提供有價值的訊息。另一個被廣泛使用的方法是DNA/DNA之雜合反應，數個不同的技術在比較不同細菌的品系上已被證實是優良的方法，於是能用以決定這些品系是否屬於同一物種，並能在堅實之基因組數據的基礎下定義細菌的新種。利用16S rRNA及DNA/DNA之雜合反應所得的資料有許多分類及命名上的價值。基因之偵測及DNA指印法之產生（由限制酶剪切，特定探針之雜合反應，聚合酶連鎖反應或合併這些技術），可以做為細菌種類的偵測鑑定以及同種細菌中不同品系之比較，這些方法逐漸可應用到傳染性病菌之檢測及流行病學上之研究。運用研究人類細菌性病原之基因方法總是需要一段時間才能用來探討魚類細菌性病原，一直到最近這些技術才被用來研究一些重要的魚類病原，如Aeromonas salmonicida，Vibrio anguillarum，Renibacterium salmoninarum及Flavoba cterium-Cytophaga等。最初所得的結果是值得嘉獎，以DNA為基礎之方法來探討魚類細菌學是可期許的。

關鍵字

DNA/DNA之雜合反應 ； 16S rRNA ； DNA指印法 ； 分子探針

並列摘要

During the past 3 decades, molecular methods have been progressively introduced for studying bacterial pathogens. These methods have allowed comparisons of bacterial strains and species at the genomic level, and their use has yielded many interesting data. Each of these methods has a certain taxonomic validity range; thus, the molecular method(s) performed in the course of a given study must be adapted to the level of taxonomic data required. For instance, as the 16S rRNA fraction is an excellent ”molecular clock”, the methods used for investigating the sequence of this molecule (first by oligonucleotide cataloging, then by DNA/rRNA hybridization and actual sequencing) were mostly effective for determining basic relationships among bacteria. Thus, they have yielded interesting information on bacterial phylogeny in the form of dendrograms. Another widely useful molecular method is DNAIDNA hybridization. Utilizing several different techniques, it has proved to be the best way to compare bacterial strains for the purpose of determining whether or not they belong to the same bacterial species. Thus, new bacterial species can be described based on firm genomic grounds. Data obtained by both 16S rRNA investigations and DNA/DNA hybridizations have produced many taxonomic and nomenclatural consequences. Gene detection and production of DNA fingerprints (by restriction endonuclease digestion, hybridization with specific probes, polymerase chain reaction, or any combination of these techniques) potentially allow the detection and identification of bacterial species as well as comparisons of strains within a bacterial species. Thus, these methods became increasingly applicable in diagnosis of infectious diseases and in epidemiological studies. There has been a delay between the application of genomic methods for characterizing human bacterial pathogens and their use for investigating fish-pathogenic bacteria. It is only recently that these techniques have been used for study of such important fish pathogens as Aeromonas salmonicida, Vibrio anguillarum, Renibacterium salmoninarum, and the Flavobacterium-Cytophaga group; but the first results are highly encouraging and the future of DNA-based methods in fish bacteriology seems promising.

並列關鍵字

DNAIDNA hybridization ； 16S rRNA ； DNA fingerprints ； Molecular probes