Molecular taxonomy of intestinal bacteria from freshwater fish and its application

对鱼的肠道细菌进行了调查，得到了以下结果。根据16S rDNA序列对分离自金鱼的肠道细菌进行了系统发育分析，将其划分为8个类群：嗜水气单胞菌、气单胞菌属、弗氏柠檬酸杆菌属、希瓦氏杆菌属、弧菌属、球菌属。梭杆菌和CFB组。同样，罗非鱼和草鱼的肠道细菌主要分为五个类群：Veronii气单胞菌、弗氏柠檬酸杆菌、志贺氏邻单胞菌、梭杆菌和CFB群。与之相对应的是，比目鱼和红鳍金枪鱼的肠道主要分为三类：鱼弧菌、弧菌和卡氏弧菌。用荧光原位杂交法分析了金鱼粪便中的细菌种群，发现金鱼粪便中含有高密度的α-，β-和γ-变形杆菌。探针AER66和BAC303可分别检出A型气单胞菌和类杆菌。用4种鱼病原菌测定了牙鲆肠道细菌的抗菌活性，发现1.7-24.3%的肠道细菌具有抗菌活性。

Intestinal bacteria of fish was investigated and the following results were obtained.1. Phylogeny of intestinal bacteria isolated from goldfish were examined based on 16S rDNA sequences and they were divided into eight clusters : Aeromonas hydrophiila, Aeromonas sp., Citrobacter freundii, Shewanella sp., Vibrio sp., Vagococcus sp. and Fusobacteria and CFB group.2. Similarly, intestinal bacteria from tilapia and grass carp were mainly classified into five clusters : Aeromonas veronii, Citrobacter freundii, Plesiomonas shigelloides, Fusobacteria and CFB group.3. Cotrary to this, intestinal tract from Japanese flounder and red seabream were mainly divided into three clusters : Vibrio fischeri, V. scophthalmi and V. carchiae.4. Bacterial populations in goldfish feces were analyzed with fluorescentl in situ hybridization method and it was found that goldfish harbors α-, β- and γ-Proteobacteria at high densities. Probes AER66 and BAC303 could detect Aeromonas and Bacteroides type A, respectively.5. Antibacterial abilities of intestinal bacteria from Japanese flounder were determined using 4 fish pathogens, and it was found that 1.7-24.3% of intestinal bacteria possess the activities.