Determination and Comparasion of Antibacterial Activity of NativeBifidobacterium Strains with Similar RAPD Profile Isolated from PairedInfants Stool and Mothers Milk

Abstract

Background: Nowadays using of Bifidobacteria as a probiotic candidate for microbiome engineering and developing of human gut immunity have been considered. Given that many previous studies have emphasized probiotic properties are strain specific and exposing to stress shock such as low pH can be effective on probiotic criteria, so this study was performed for assessment and comparasion of antagonist activity of native Bifidobacterium with similar genotype homolgy isolated from paired mothers milk and infants feces. Methods: In this study, 56 mother’s milk and paired-infant feces were taken from rural area. Single colonies were picked up and confirmed by phenotypic and molecular identification. Randomly amplified polymorphic DNA (RAPD- PCR) and antibacterial activity carried out on selected strains. Results: Amongst all 56 samples, 31 samples, including 20 stools and 11 milks were positive for Bifidobacterium including B. breve, B. longum, B. bifidum. 12 of all strains were shared between stool and milk, including 6 Bifidobacterium longum, 4 B. breve and 2 B. bifidum. Between these 12 strains, only three strains of Bifidobacterium longum presented 100% similarity in RAPD- PCR analysis and antibacterial activity were strains specific and no similar activity were observed. Conclusion: In short, amongst all 56 paired infants stools and mothers milks, 12 different shared Bifidobacteria were isolated and identified that showed strain specific antagonist activity and some of these isolates possibly produced bacteriocin like proteins.