الفهرس 
Introduction
Description of BifidobacteriumOnly 14 pages are availabe for public view
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Abstract
This study was conducted on 73 infants divided into 2 groups according to their feeding type, breast-fed group (35 infant) and formula fed group (38 infant).
All infants enrolled to this study are born in median gestational age of 38 weeks with a median weight 3.2 Kg.
Samples of human milk, formula milk and samples of infant’s stool were collected.
Milk samples were cultured in MRS-CYS plates and incubated at 37°C for 48 hr. anaerobically in an anaerobic jar using AnaeroGen 2.5L compact gas packs, isolates were characterized based on their colony morphology, microscopic appearance after Gram staining.
DNA was extracted from the isolates and purified using a GeneJET Genomic DNA Purification Kit (Thermo scientific). For stool samples, DNA extraction was done using QIAamp DNA stool kit purchased from Qiagen / Germany.
All samples were identified to genus level and Bifidobacterium genus-specific primer was used. Further identification to species level was done and species-specific primers were used (B.breve, B.longum, B.bifidum, B.infantis).
For human milk samples, only (11/35)31.4% gave growth on the MRS-Cys media and isolates belonging to two Bifidobacteria species were isolated from breast milk samples: B.breve (7 milk samples), B.bifidum (6 samples).
For stool samples of breast-fed infants, the isolated species were
B. breve (29 samples), B.bifidum (22 samples) and B.infantis (7samples), B.longum (11 samples).
For stool samples of formula fed infants, the isolated species were B. breve (33 samples), B. bifidum (25 samples) and B.infantis (13 samples), B. longum (3 samples).
Out of the 73 stool samples, real time PCR was done for only 56 samples (27 breast-fed and 29 formula fed infants).
Concerning the bifidobacteria count in both groups, the count was significantly higher in the stool samples of the breast-fed infants compared to the formula-fed infants (P 0.008). On the other hand, the sex of the infant and the mode of delivery had no significant impact on the bifidobcteria count.