代表性差异分析比较两株来自不同地区的猪源Lactobacillus菌株

目的]对分离自猪肠道的乳酸杆菌S1菌株进行鉴定,并比较该菌株与同种的001T菌株的基因差异.方法]对S1菌株进行16S rRNA基因序列分析和种特异PCR检测,并且对S1菌株和Lactobacillus sobrius 001T进行代表性差异分析(Representational difference analysis,RDA).结果]16S rRNA基因序列分析表明,与S1菌株最相似的已知菌为L.sobrius.变性梯度凝胶电泳分析显示,仔猪空、回肠细菌图谱中有一与S1菌株有相同迁移位置的优势条带,克隆、测序鉴定表明,与该条带相匹配的16S rRNA基因克隆(Clone S)的最相似已知菌也为L.sobrius.16S rRNA基因系统进化分析表明,S1菌株与Clone S和L.sobrius 16S rRNA基因序列同源性分别为99.8%和99.6%.L.sobrius特异性引物也可以扩增S1株菌的16S rRNA基因的特定片段.因此S1菌株可被确定为Lsobrius.RDA对菌株S1和同种的猪源L.sobrius 001T菌株的基因差异进行分析,未发现这两株菌的基因组差异.结论]猪肠道乳杆酸菌S1菌株属于L.sobrius,其与猪源L sobrius 001T菌株为相似菌株.

Comparison of two Lactobacillus strains isolated from piglets in different area by using representational difference analysis

Objective] To identify Lactobacillus sp. strain S1 from the intestine of piglet, and compare the genomic difference between this strain and Lactobacillus sobrius 001T. Methods] Analysis of 16S rRNA gene sequence and species-specific polymerase chain reaction assay were used to identify Lactobacillus sp. strain S1. Representational difference analysis (RDA) was used to compare these two strains. Results] The 16S rRNA gene sequence analysis of strain S1 showed that its closest known species in the GenBank database was L. sobrius. Denaturing gradient gel electrophoresis analysis showed that the predominant bands in profiles from bacteria in the jejunum and ileum of piglets had the identical migrating position with strain S1. Cloning and sequencing of 16S rRNA gene analysis revealed that this band matched clone (Clone S) was also related closely to L. sobrius. Phylogenetic analysis of 16S rRNA gene showed that homology between strain S1 and Clone S was 99.8%, and that between strain S1 and L. sobrius was 99.6%. Both strains could be detected in 1.2% agarose gel by L. sobrius-specific PCR assay. Recently, RDA has been adapted to study the genomic diversity of bacterial strains. This analysis showed that there was no genomic difference between the two strains. Conclusion] Piglet-derived strain S1 belonged to L. sobrius. Piglet-derived L. sobrius 001T and L. sobrius S1 were the similar strain.