Identification of Bifidobacterium strains from faeces of lambs

Abstract

Bifidobacteria were enumerated and isolated from the faeces of lambs aged between 25 and 40days using modified trypticase–phytone–yeast extract (TPY) agar supplemented with mupirocin and acetic acid. Nineteen strains were characterised and divided into 6 groups according their fermentation characteristics obtained by API 50 CHL and RAPID ID 32 tests and by randomly amplified polymorphic DNA (RAPD) profiles. One representative strain of each group was identified by sequencing by 16S rRNA and hsp60 genes sequencing as B. animalis ssp. animalis, B. choerinum, B. pseudolongum ssp. globosum, B. pseudocatenulatum. Examination of the DNA fingerprinting showed a genetic diversity between strains of B. animalis ssp. animalis and B. choerinum. Our result shows that some bifidobacterial species should not be host-specific or have a broad host spectrum. As bifidobacteria were determined as numerous bacterial group in the intestine of lambs on a milk diet (8.32±0.71logCFU/g, mean count±S.D., n=30), there is a reasonable presumption that bifidobacteria could be an effective probiotics for lambs. Identification techniques used in this study were found to be suitable for the classification of lamb origin bifidobacteria.