摘要
20世纪70年代末,采用形态分类学方法,将引起柞蚕空胴病的致病菌鉴定为柞蚕链球菌(Streptococcus pernyi sp.nov)。分别提取已分离柞蚕空胴病的5株病原菌株的基因组DNA,PCR扩增16S rRNA基因片段,经克隆、测序后,与GenBank中登录的相关肠球菌、链球菌菌株的16S rRNA基因序列进行同源性比对并构建系统进化树。结果表明,供试的5株菌株的16S rRNA基因序列相似性在99.5%～99.9%之间,相互之间存在着10个可变位点,推测5株菌株属于同一个菌种;5株菌株的16S rRNA基因序列与肠球菌属(Enterococcus)16S rRNA基因序列的相似性较高,在92.4%～99.8%之间,而与链球菌属(Streptococcus)16S rRNA基因序列的相似性相对较低,在87.3%～87.8%之间;5株菌株与肠球菌属在系统进化树上聚为一类。基于菌株的16S rRNA基因序列分析,鉴定柞蚕空胴病的病原菌应归属于肠球菌属。
The pathogen causing empty-gut disease in Antheraea pernyi was identified as Streptococcus pernyi sp.nov by the end of 1970s according to its morphological characters.In this study,we isolated genomic DNAs from 5 different isolates of pathogen causing empty-gut disease in Antheraea perny and amplified their 16S rRNA gene fragments by PCR.After cloning and sequencing,the 16S rRNA gene sequences were compared with those from other strains of Enterococcus and Streptococcus registered in GenBank based on which a phylogenetic tree was constructed.The results indicated that sequence identity of 16S rRNA genes between the 5 isolates ranged from 99.5% to 99.9% and 10 sites were found to have various bases,suggesting that the 5 isolates belong to the same bacterial species.16S rRNA genes of the 5 isolates had higher sequence identity（92.4% ~ 99.8%） with those of Enterococcus and lower sequence identity（87.3% ~ 87.8%） with those of Streptococcus.Phylogenetic tree showed that the 5 isolates were clustered together with Enterococcus.Based on 16S rRNA gene sequence analysis,the pathogen that causes empty-gut disease in Antheraea pernyi should be identified as a species of Enterococcus.
出处
《蚕业科学》
CAS
CSCD
北大核心
2011年第5期931-936,共6页
ACTA SERICOLOGICA SINICA
基金
现代农业产业技术体系专项(No.CARS-22)
