The effects of Bifidobacterium bifidum OFR9, a strain resistant to antituberculosis and antileprosy agents, on fecal flora in mice.

Abstract

Since Bifidobacterium bifidum, one of the strains of medical preparations used for human intestinal disorders, is sensitive to rifampicin (RFP) and fluoroquinolones, its therapeutic effect cannot be guaranteed when it is administered concomitantly with these antibiotics. To develop new strains of B. bifidum that are resistant to these drugs, B. bifidum RFR61, which is highly resistant to RFP, was selected by the N-methyl-N'-nitrosoguanidine (MNNG) mutation method. Then, B. bifidum OFR9 was selected in vitro from B. bifidum RFR61 by serial passage to increasing concentrations of oflloxacin (OFLX) on a solid medium. The minimal inhibition concentrations (MIC) of RFP and fluoroquinolones for B. bifidum OFR9 were >256 µg/ml and 16-256 µg/ml, respectively. We investigated the effects of B. bifidum OFR9 on the fecal bacterial flora of mice administered with both antibiotics and B. bifidum OFR9. The results showed that the concurrent use of B. bifidum OFR9 and antibiotics prevented the decrease of bifidobacteria, and quickly restored the flora to normal as compared with the use of antibiotic or parent strain therapy alone. The survival of Shigella organisms in mouse feces rapidly decreased, and were removed within two days as a result of the oral administration of B. bifidum OFR9.

Implication of an Outer Surface Lipoprotein in Adhesion of Bifidobacterium bifidum to Caco-2 Cells

“…However, other species of the genus Bifidobacterium have been studied more, such as B. longum, B. adolescentis, and B. animalis subsp. lactis (1,11,12,37,43,54).…”

Cloning and Characterization of the Bile Salt Hydrolase Genes ( bsh ) from Bifidobacterium bifidum Strains

“…Bifidobacterium bifidum is one of the major bifidobacterial species commonly detected in human feces (29), and it was proposed that a high level of B. bifidum was an indication of the typical Bifidobacterium flora in healthy infants as opposed to low levels in allergic infants (19). Attempts have been made in recent years to define some beneficial effects of B. bifidum strains, including antibacterial activities (1,39), immunostimulating activity (24,35), antioxidative properties (20), production of bacteriocins (53), improvement of the microbial balance (6), and reduction of inflammation in broiler chickens (14).…”