Open AccessIsolation of Bifidobacteria from Breast Milk and Assessment of the Bifidobacterial Population by PCR-Denaturing Gradient Gel Electrophoresis and Quantitative Real-Time PCR
Author(s) -
Rocı́o Martı́n,
Esther Jiménez,
Hans G.H.J. Heilig,
Leónides Fernández,
María Marín,
Erwin G. Zoetendal,
Juan M. Rodríguez
Publication year - 2009
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.02063-08
Subject(s) - bifidobacterium bifidum , biology , bifidobacterium longum , bifidobacterium , temperature gradient gel electrophoresis , bifidobacterium breve , 16s ribosomal rna , actinomycetaceae , feces , microbiology and biotechnology , polymerase chain reaction , breast milk , food science , bacteria , lactobacillus , genetics , gene , fermentation , biochemistry
The objective of this work was to elucidate if breast milk contains bifidobacteria and whether they can be transmitted to the infant gut through breastfeeding. Twenty-three women and their respective infants provided samples of breast milk and feces, respectively, at days 4 to 7 after birth. Gram-positive and catalase-negative isolates from specific media with typical bifidobacterial shapes were identified to the genus level by F6PPK (fructose-6-phosphate phosphoketolase) assays and to the species level by 16S rRNA gene sequencing. Bifidobacterial communities in breast milk were assessed by PCR-denaturing gradient gel electrophoresis (PCR-DGGE), and their levels were estimated by quantitative real-time PCR (qRTi-PCR). Bifidobacteria were present in 8 milk samples and 21 fecal samples.Bifidobacterium breve ,B. adolescentis , andB. bifidum were isolated from milk samples, while infant feces also containedB. longum andB. pseudocatenulatum . PCR-DGGE revealed the presence of one to four dominant bifidobacterial bands in 22 milk samples. Sequences with similarities above 98% were identified asBifidobacterium breve ,B. adolescentis ,B. longum ,B. bifidum , andB. dentium. Bifidobacterial DNA was detected by qRTi-PCR in the same 22 milk samples at a range between 40 and 10,000 16S rRNA gene copies per ml. In conclusion, human milk seems to be a source of living bifidobacteria for the infant gut.