Phenotypic and genotypic characterization of Bifidobacterium isolates from healthy adult Koreans

Document Type: Research Paper

Authors

1 College of Pharmacy, Sahmyook University, Seoul 139-742, Republic of Korea.

2 Food R and D Center, Sahmyook Foods, Chunan, Chungcheongnamdo 330-810, Republic of Korea.

3 Department of Life Science, Sahmyook University, Seoul 139-742, Republic of Korea.

Abstract

A total of twenty-two strict anaerobic and Gram-positive Bifidobacteria, identified as B. adolescentis, B.
pseudocatenulatum, or B. longum, were isolated from healthy adult Koreans. We here investigated the cell
morphology, antimicrobial resistance patterns to novel antibiotics and genotypic differentiation of
Bifidobacteria assessing repetitive DNA element PCR (rep-PCR) fingerprinting using the BOXA1R primer at
the species level. All Bifidobacterium spp., except B. adolescentis SPM1005 and B. longum SPM1205,
formed round and convex colonies. All B. adolescentis, B. pseudocatenulatum, and B. longum were opaque
white glossy in colony color, and short, long, and irregular rods in morphological shape. In addition, all B.
adolescentis, B. pseudocatenulatum, and B. longum formed a variety of shapes ranging from rods to Vshaped, Y-shaped, clubbed rods, or irregular. All Bifidobacterium spp., except B. adolescentis
SPM0214, were sensitive to daptomycin (DAP), linezolid (LIN), and tigecycline (TIG). B. adolescentis
SPM0214 was resistant to DAP. Genomic fingerprinting patterns of B. adolescentis, B. pseudocatenulatum,
and B. longum were diverse and different from those of the KCTC strain. The band size of B. adolescentis, B.
pseududocatenulatum, and B. longum varied from 3.0 kb to 300 bp, 2.0 kb to 200 bp, and 2.0 kb to 500 bp,
respectively. In conclusion, twenty-two strains of B.adolescentis, B. pseudocatenulatum, and B. longum
isolated from healthy adult Koreans were very diverse in both phenotype and genotype. Moreover, this diversity of phenotype and genotype may support that health promoting effects of individual strain of
Bifidobacterium spp. human isolates could be differentand specific even within same species.

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