Simultaneous identification of five Bifidobacterium species isolated from human beings using multiple PCR primers

On the basis of 16S rRNA sequences, 5 species-specific forward primers were designed for the identification of 5 Bifidobacterium species isolated from human intestine, namely B. bifidium, B. adolescentis, B. infantis, B. brev e and B. longum. As the 5 primers targeted at different sites of 16S rDNA, by using their mixture and a genus-specific reversed primer, the 5 Bifidoba cterium species can be simultaneously identified in individual or in mixed culture through PCR amplification. The specificity of the primers was confi rmed by the use of genomic DNAs from type strains of all 32 Bifidobacterium species and 6 other relatives. The 5-primer mixture was also applied to th e identification of Bifidobacterium strains used commercially. The results turned out to be in accordance with chose from conventional identification. This multiple-primer method provides a useful tool for rapid identificatio n of the 5 Bifidobacterium species indicated.