鳗鲡病原性气单胞菌AFLP分型研究

DNA Fingerprint Typing Analysis by AFLP for Pathogenic Aeromonassp.Isolated from Diseased Eels

以32株从养殖鳗鲡分离的病原性气单胞菌为试验材料,采用Biolog自动菌鉴系统对其进行生理生化鉴定,结果表明,有20株被鉴定为嗜水气单胞菌,7株被鉴定为威隆气单胞菌,1株为豚鼠气单胞菌,其余4株未能鉴定到种.为进一步确定20株嗜水气单胞菌和7株威隆气单胞菌的基因型,筛选了2对引物(E-C/M-C,E-C/M-A)分别对这两个菌种进行了AFLP分析.结果表明:20株嗜水气单胞菌中共检测到88个位点,均为多态性位点;7株威隆气单胞菌中共检测到61个位点,其中60个为多态性位点.经UPGMA聚类分析表明:20株嗜水气单胞菌可初步分为3种类型,每种类型之间平均遗传距离为0.449,同一类型内不同菌株的平均遗传距离为0.127;7株威隆气单胞菌可初步分为4种类型,每种类型之间平均遗传距离为0.467,变异范围为0.415～0.525.该结果为鱼类病原菌的DNA分型研究提供了参考.

Thirty-two pathogens isolated from diseased eels and classified as the genus of Aromonas sp.were further identified by an automatic biochemical identification system of Biolog.The results showed that 20 pathogens were identified as Aromonas hyplrophila,7 pathogehs were Aromonas veronii,and 1 pathogen was Aromonas caviae,respectively.Another 4 strains were identified as the genus of Aromonas.The 20 strains of Aromonas hydrophila and 7 strains of Aromonas veronii were then analyzed by Amplified Fragment Length Polymorphism（AFLP） to ascertain the DNA finger typing.The results showed that 88 loci were amplified by two pairs of primers（E-C/M-C and E-C/M-A） with all polymorphic loci in Aromonas hydrophila and 61 loci were amplified by the same primers with 60 polymorphic loci in Aromonas veronii.The UPGMA（Unweighted Pair Group Method with Arithmetic Mean Analysis） dendrogram showed that 20 strains of Aromonas hydrophila and 7 strains of Aromonas veronii can be primarily divided into 3 and 4 DNA finger typing respectively.The average distance of gene diversity between and in 3 DNA finger typing of Aromonas hydrophila was 0.449 and 0.127 respectively.The average distance of gene diversity between 4 DNA finger typing of Aromonas veronii was 0.467 and ranged from 0.415 to 0.525.The research provided a new technology for the DNA finger typing of fish pathogens.