Cultivable Bacteria from Milk from Slovenian Breastfeeding Mothers
Tina Tušar1, Klavdija Žerdoner1, Bojana Bogovič Matijašić1*, Diana Paveljšek1, Evgen Benedik2, Borut Bratanič3, Nataša Fidler2 and Irena Rogelj1
1Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Groblje 3, SI-1230 Domžale, Slovenia
2Department of Gastroenterology, Hepatology and Nutrition, University Children’s Hospital Ljubljana, University Medical Centre Ljubljana, Bohoričeva 20, SI-1000 Ljubljana, Slovenia
3Department of Neonatology, University Children’s Hospital Ljubljana, University Medical Centre Ljubljana, Bohoričeva 20, SI-1000 Ljubljana, Slovenia
Article history:
Received November 30, 2013
Accepted March 5, 2014
Key words:
human milk, cultivable microbiota, RAPD PCR, Lactobacillus sp., 16S rDNA sequencing
Summary:
The human milk microbiota plays an important role in the development of infant´s intestinal microbiota and in the protection of infants against pathogenic microorganisms. The aim of this study is to investigate the microbial composition of human milk from 47 breastfeeding mothers, sampled separately from the left (L) and the right (R) breast, on the 30th day after giving birth. We quantified some major bacterial groups in human milk, compared the cultivable bacteria from the left and the right breast and identified strain diversity of lactobacilli. The results revealed that human milk contains lactic acid bacteria, bifidobacteria and mesophilic aerobic bacteria, of which the last were the most abundant group. Although the microbial composition of human milk in L and R breast samples was comparable, the concentration of bacteria in the two samples from the same mother might vary, therefore milk sample taken from one breast only does not reflect the average microbial composition. Using random amplified polymorphic DNA (RAPD), 86 presumptive isolates of lactobacilli from representative samples of human milk from 11 mothers were classified into 11 groups. Moreover, representatives of different RAPD groups were identified using 16S rDNA sequencing. Out of 11 RAPD groups, 4 groups (21 % of all isolates) belonged to the species Lactobacillus gasseri. The most representative RAPD profile (48 % of isolates) was found to belong to the species Lactobacillus fermentum. Other RAPD groups were associated with L. salivarius, L. reuteri, Enterococcus faecium, Staphylococcus epidermidis and Bifidobacterium breve species.
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