Rapid identification of human intestinal bifidobacteria by 16S rRNA-targeted species- and group-specific primers.

On the basis of 16S rRNA sequences, species- and group-specific primers for Bifidobacterium adolescentis, B. angulatum, B. bifidum, B. breve, the B. catenulatum group (B. catenulatum and B. pseudocatenulatum), and the B. longum group (B. longum and B. infantis), which are species commonly found in human intestinal tracts, were developed. The specificity of these primers was confirmed through the use of DNA extracted from 46 strains of 31 Bifidobacterium species, as well as 14 non-bifidobacterial species that are the predominant bacteria in the human intestinal tract. The present species-specific primers were applied to the identification of 43 isolated strains, consisting of six strains of B. adolescentis, eight of the B. catenulatum group, seven of B. bifidum, nine of B. breve, and 13 of the B. longum group.