scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Isolation of commensal bacteria from umbilical cord blood of healthy neonates born by cesarean section.

TL;DR: Investigation of presence of lactic acid bacteria in umbilical cord blood of healthy neonates born by elective cesarean section suggested that term fetuses are not completely sterile, and that a mother-to-child efflux of commensal bacteria may exist.
Abstract: In a previous study, lactic acid bacteria were isolated from meconium obtained from healthy neonates born by cesarean section. Such a finding suggested that term fetuses are not completely sterile, and that a mother-to-child efflux of commensal bacteria may exist. Therefore, presence of such bacteria in umbilical cord blood of healthy neonates born by elective cesarean section was investigated. The blood samples were submitted to an enrichment step and then inoculated onto agar plates. All the identified isolates belonged to the genus Enterococcus, Streptococcus, Staphylococcus, or Propionibacterium. Later, a group of pregnant mice were orally inoculated with a genetically labeled E. faecium strain previously isolated from breast milk of a healthy woman. The labeled strain could be isolated and polymerase chain reaction detected from the amniotic fluid of the inoculated animals. In contrast, it could not be detected in the samples obtained from a noninoculated control group.
Citations
More filters
Journal ArticleDOI
29 Apr 2016-Science
TL;DR: The role of early-life education of the immune system during this “window of opportunity,” when disruption of optimal host-commensal interactions can lead to persistent and in some cases irreversible defects in the development and training of specific immune subsets is discussed.
Abstract: Microbial colonization of mucosal tissues during infancy plays an instrumental role in the development and education of the host mammalian immune system. These early-life events can have long-standing consequences: facilitating tolerance to environmental exposures or contributing to the development of disease in later life, including inflammatory bowel disease, allergy, and asthma. Recent studies have begun to define a critical period during early development in which disruption of optimal host-commensal interactions can lead to persistent and in some cases irreversible defects in the development and training of specific immune subsets. Here, we discuss the role of early-life education of the immune system during this “window of opportunity,” when microbial colonization has a potentially critical impact on human health and disease.

1,232 citations

Journal ArticleDOI
TL;DR: A review discusses recent studies on the early colonization and factors influencing this process which impact on health and an adequate establishment of microbiota and its maintenance throughout life would reduce the risk of disease in early and late life.
Abstract: The intestinal microbiota has become a relevant aspect of human health. Microbial colonization runs in parallel with immune system maturation and plays a role in intestinal physiology and regulation. Increasing evidence on early microbial contact suggest that human intestinal microbiota is seeded before birth. Maternal microbiota forms the first microbial inoculum, and from birth, the microbial diversity increases and converges toward an adult-like microbiota by the end of the first 3-5 years of life. Perinatal factors such as mode of delivery, diet, genetics, and intestinal mucin glycosylation all contribute to influence microbial colonization. Once established, the composition of the gut microbiota is relatively stable throughout adult life, but can be altered as a result of bacterial infections, antibiotic treatment, lifestyle, surgical, and a long-term change in diet. Shifts in this complex microbial system have been reported to increase the risk of disease. Therefore, an adequate establishment of microbiota and its maintenance throughout life would reduce the risk of disease in early and late life. This review discusses recent studies on the early colonization and factors influencing this process which impact on health.

980 citations


Cites background from "Isolation of commensal bacteria fro..."

  • ...cord blood (6), amniotic fluid (7 9), and fetal membranes...

    [...]

  • ...To test whether maternal gut bacteria can be transferred to fetuses in utero, two pioneer studies investigated if oral administration of a genetically labeled Enterococcus faecium to pregnant mice resulted in its presence in amniotic fluid and meconium of term offspring after sterile cesarean section (C-section) (6, 8)....

    [...]

Journal ArticleDOI
TL;DR: The infant microbiota, the mechanisms that drive its establishment and composition, and how microbial consortia may be molded by natural or artificial interventions are described and the relevance of key microbial players of the infant gut microbiota, in particular bifidobacteria, with respect to their role in health and disease are discussed.
Abstract: The human gut microbiota is engaged in multiple interactions affecting host health during the host's entire life span. Microbes colonize the neonatal gut immediately following birth. The establishment and interactive development of this early gut microbiota are believed to be (at least partially) driven and modulated by specific compounds present in human milk. It has been shown that certain genomes of infant gut commensals, in particular those of bifidobacterial species, are genetically adapted to utilize specific glycans of this human secretory fluid, thus representing a very intriguing example of host-microbe coevolution, where both partners are believed to benefit. In recent years, various metagenomic studies have tried to dissect the composition and functionality of the infant gut microbiome and to explore the distribution across the different ecological niches of the infant gut biogeography of the corresponding microbial consortia, including those corresponding to bacteria and viruses, in healthy and ill subjects. Such analyses have linked certain features of the microbiota/microbiome, such as reduced diversity or aberrant composition, to intestinal illnesses in infants or disease states that are manifested at later stages of life, including asthma, inflammatory bowel disease, and metabolic disorders. Thus, a growing number of studies have reported on how the early human gut microbiota composition/development may affect risk factors related to adult health conditions. This concept has fueled the development of strategies to shape the infant microbiota composition based on various functional food products. In this review, we describe the infant microbiota, the mechanisms that drive its establishment and composition, and how microbial consortia may be molded by natural or artificial interventions. Finally, we discuss the relevance of key microbial players of the infant gut microbiota, in particular bifidobacteria, with respect to their role in health and disease.

970 citations


Cites background from "Isolation of commensal bacteria fro..."

  • ...Infants born by C-section also show a reduced complexity of the gut microbiota and are less often colonized by microorganisms such as Bifidobacterium and Bacteroides, while being more frequently colonized by members of Clostridium sensu stricto (cluster I) and Clostridium difficile (70, 71, 74–79)....

    [...]

  • ...To test whether maternal gut bacteria can be provisioned to fetuses in utero, two pioneering studies investigated whether oral administration of genetically labeled Enterococcus faecium to pregnant mice resulted in its presence in the amniotic fluid and meconium of term offspring after sterile C-section (61, 198)....

    [...]

  • ...Moreover, no statistically significant difference was observed between bacterial communities harbored by the milk of women who delivered at term or preterm, delivered vaginally or by caesarean section (C-section), or gave birth to boys or girls (242)....

    [...]

  • ...Proteobacteria and Firmicutes were reported to be the main phyla represented during the first days of life, with Actinobacteria appearing in the feces of C-section-delivered babies at day 7 to 15 following birth (74)....

    [...]

  • ...This apparent process of extinction of bifidobacteria may have been due to modifications of the human diet, including the widespread use of formula milk instead of breast milk, yet may also be due to or compounded by other factors, such as the use of antibiotics, increased hygiene, and C-sections....

    [...]

Journal ArticleDOI
TL;DR: The concept of parallel and interacting microbial-neural critical windows opens new avenues for developing novel microbiota-modulating based therapeutic interventions in early life to combat neurodevelopmental deficits and brain disorders.

810 citations

Journal ArticleDOI
TL;DR: Bacteria were able to be isolated from umbilical cord blood of healthy neonates and from murine amniotic fluid obtained by caesarean section and suggested that term fetuses are not completely sterile and that a prenatal mother-to-child efflux of commensal bacteria may exist.

797 citations


Cites background from "Isolation of commensal bacteria fro..."

  • ...Recently, it has been shown that the maternal digestive tract may be the origin of bacteria found in amniotic fluid [7,14,16]; therefore, the second objective of this study was to elucidate whether oral administration of a bacterial strain to pregnant mice may lead to its presence in fetal meconium....

    [...]

  • ...007 healthy pregnancies has not been assessed despite the fact that bacteria can be isolated and/or PCR-detected in umbilical cord blood, amniotic fluid and fetal membranes without any clinical or histological evidence of infection or inflammation in the mother-infant pair [3,13,14,35]....

    [...]

References
More filters
Journal ArticleDOI
TL;DR: A new mechanism for bacterial uptake in the mucosa tissues that is mediated by dendritic cells (DCs) is reported, which open the tight junctions between epithelial cells, send dendrites outside the epithelium and directly sample bacteria.
Abstract: Penetration of the gut mucosa by pathogens expressing invasion genes is believed to occur mainly through specialized epithelial cells, called M cells, that are located in Peyer's patches. However, Salmonella typhimurium that are deficient in invasion genes encoded by Salmonella pathogenicity island 1 (SPI1) are still able to reach the spleen after oral administration. This suggests the existence of an alternative route for bacterial invasion, one that is independent of M cells. We report here a new mechanism for bacterial uptake in the mucosa tissues that is mediated by dendritic cells (DCs). DCs open the tight junctions between epithelial cells, send dendrites outside the epithelium and directly sample bacteria. In addition, because DCs express tight-junction proteins such as occludin, claudin 1 and zonula occludens 1, the integrity of the epithelial barrier is preserved.

2,463 citations

Journal ArticleDOI
TL;DR: Gut microflora might be a hitherto unexplored source of natural immunomodulators and probiotics, for prevention of atopic disease in children at high risk.

2,429 citations

Journal ArticleDOI
TL;DR: In this review, the development of the intestinal microbiota is discussed in terms of initial acquisition and subsequent succession of bacteria in human infants and the advantages of modern molecular ecology techniques that provide sensitive and specific, culture-independent evaluation of the gastrointestinal ecosystem are introduced.

1,304 citations


"Isolation of commensal bacteria fro..." refers background in this paper

  • ...Since the old studies of Tissier [23] concerning the acquisition of the infant gut microbiota, the idea that fetuses are sterile in utero and that bacterial colonization of the newborn intestinal tract starts during the transit through the labor channel, due to cross-contamination with vaginal and fecal bacteria of the maternal microflora, has been widely accepted [16, 22]....

    [...]

Journal ArticleDOI
TL;DR: This study showed that using PCR-DGGE and 16S rDNA sequence analysis together resulted in a dynamic description of bacterial colonization in the infant intestinal ecosystem and allowed visualization of bacteria that are difficult to cultivate or to detect by other methods.
Abstract: The establishment of bacterial communities in two healthy babies was examined for more than the first 10 months of life by monitoring 16S ribosomal DNA (rDNA) diversity in fecal samples by PCR and denaturing gradient gel electrophoresis (DGGE) and by analyzing the sequences of the major ribotypes. DGGE profiles of the dominant populations in the intestines of the infants were obtained by analyzing daily or weekly fecal samples. After delivery, the germfree infant gastrointestinal tracts were rapidly colonized, and the succession of bacteria in each ecosystem was monitored. During the first few days of life the profiles were simple, but they became more complex as the bacterial diversity increased with time in both babies. Clone libraries of amplified 16S rDNA fragments from baby feces were constructed, and these libraries allowed identification of the bacterial types by comparative DNA sequence analysis; the bacteria identified included members of the genera Bifidobacterium, Ruminococcus, Enterococcus, Clostridium, and Enterobacter. Species most closely related to the genera Bifidobacterium and Ruminococcus in particular dominated the intestinal microbiota based on the stability over time and the numbers, as estimated by the intensities of the bands. However, 19 of the 34 cloned rDNA sequences exhibited less than 97% identity with sequences of known bacteria or cloned sequences in databases. This study showed that using PCR-DGGE and 16S rDNA sequence analysis together resulted in a dynamic description of bacterial colonization in the infant intestinal ecosystem and allowed visualization of bacteria that are difficult to cultivate or to detect by other methods.

837 citations

Journal ArticleDOI
TL;DR: Comparing the bacteria found in early childhood caries (ECC) to those found in caries-free children by using molecular identification methods suggests that A. gerencseriae and other Actinomyces species may play an important role incaries initiation and that a novel Bifidobacterium may be a major pathogen in deep caries.
Abstract: Although substantial epidemiologic evidence links Streptococcus mutans to caries, the pathobiology of caries may involve more complex communities of bacterial species. Molecular methods for bacterial identification and enumeration now make it possible to more precisely study the microbiota associated with dental caries. The purpose of this study was to compare the bacteria found in early childhood caries (ECC) to those found in caries-free children by using molecular identification methods. Cloning and sequencing of bacterial 16S ribosomal DNAs from a healthy subject and a subject with ECC were used for identification of novel species or uncultivated phylotypes and species not previously associated with dental caries. Ten novel phylotypes were identified. A number of species or phylotypes that may play a role in health or disease were identified and warrant further investigation. In addition, quantitative measurements for 23 previously known bacterial species or species groups were obtained by a reverse capture checkerboard assay for 30 subjects with caries and 30 healthy controls. Significant differences were observed for nine species: S. sanguinis was associated with health and, in order of decreasing cell numbers, Actinomyces gerencseriae, Bifidobacterium, S. mutans, Veillonella, S. salivarius, S. constellatus, S. parasanguinis, and Lactobacillus fermentum were associated with caries. These data suggest that A. gerencseriae and other Actinomyces species may play an important role in caries initiation and that a novel Bifidobacterium may be a major pathogen in deep caries. Further investigation could lead to the identification of targets for biological interventions in the caries process and thereby contribute to improved prevention of and treatment for this significant public health problem.

699 citations


"Isolation of commensal bacteria fro..." refers background in this paper

  • ...sanguinis is recognized for its antagonistic role in dental caries and periodontal diseases [2], and its artificial implantation in the oral cavity has already been proposed as a probiotic approach to prevent caries, including measures that foster a mother-to-child transmission [4]....

    [...]

Related Papers (5)