Study of fecal microbiota in healthy infant in Ubon Ratchathani province

The objective of this study was to investigate the bacterial species of Bifidobacterium ssp. and Lactobacillus ssp. presented in fecal samples of healthy breastfed infants. The selection of species for study was based on the predominant species in the human gastrointestinal tract. Totally, one feces sample was collected from a volunteer who was born by cesarean birth. He was two months old of age. Fifty single colonies with clear zones around their colonies were selected from MRS agar medium containing calcium carbonate under anaerobic conditions. Gram staining revealed that all bacterial isolates were gram-positive with a Y-like and bacilli shape, catalase negative, indicated that all these fifty isolates were possibility as Bifidobacterium species. For these reasons, the specific primers and PCR condition for identification of Bifidobacterium species including Bifidobacterium infantis, Bifidobacterium bifidum, Bifidobacterium longum and Bifidobacterium breve were used. The result demonstrated that all bacterial isolates were not Bifidobacterium bifidum and Bifidobacterium longum, due to the specific band were not detected from genomic DNA sample. For Bifidobacterium breve, the bacterial isolates JB1 could show the specific band of 288 bp., indicated that this isolate was belonged B.breve. For identification of Bifidobacterium infantis, it was demonstrated that all genomic DNA showed non-specific bands were still presented in the mixture of amplified PCR product. Thus, the PCR conditions are required for optimization.