Rapid identification of potentially probiotic Bifidobacterium species by multiplex PCR using species-specific primers based on the region extending from 16S rRNA through 23S rRNA.

This study aimed at developing a novel multiplex polymerase chain reaction (PCR) primer set for identification of the potentially probiotic Bifidobacterium species B. adolescentis, B. animalis subsp. animalis (B. animalis), B. bifidum, B. breve, B. longum biovar infantis (B. infantis), B. animalis subsp. lactis B. lactis, B. longum biovar longum (B. longum) and B. pseudolongum. The primer set comprised specific and conserved primers and was derived from the integrated sequences of 16S and 23S rRNA genes and the rRNA intergenic spacer region (ISR) of each species. It could detect and identify type strains and isolates from pharmaceuticals or dairy products corresponding to the eight Bifidobacterium species with high specificity. It was also useful for screening of the related strains from natural sources such as the gastro-intestinal tract and feces. We suggest that the assay system from this study is an efficient tool for simple, rapid and reliable identification of Bifidobacterium species for which probiotic strains are known.