title: Establishment of the bacterial fecal community during the first month of life in Brazilian newborns.
abstract: OBJECTIVE
  The establishment of the intestinal microbiota in newborns is a critical period with possible long-term consequences for human health. In this research, the development of the fecal microbiota of a group of exclusively breastfed neonates living in low socio-economic conditions in the city of São Paulo, Brazil, during the first month of life, was studied.
  
  
  METHODS
  Fecal samples were collected from ten neonates on the second, seventh, and 30(th) days after birth. One of the neonates underwent antibiotic therapy. Molecular techniques were used for analysis; DNA was extracted from the samples, and 16S rRNA libraries were sequenced and phylogenetically analyzed after construction. A real-time polymerase chain reaction (PCR) was performed on the samples taken from the 30(th) day to amplify DNA from Bifidobacterium sp.
  
  
  RESULTS
  The primary phylogenetic groups identified in the samples were Escherichia and Clostridium. Staphylococcus was identified at a low rate. Bifidobacterium sp. was detected in all of the samples collected on the 30(th) day. In the child who received antibiotics, a reduction in anaerobes and Escherichia, which was associated with an overgrowth of Klebsiella, was observed throughout the experimental period.
  
  
  CONCLUSIONS
  The observed pattern of Escherichia predominance and reduced Staphylococcus colonization is in contrast with the patterns observed in neonates living in developed countries.
authors.affiliation: Universidade de São Paulo, School of Medicine, Hospital das Clínicas, Children's Hospital, Brazil.
authors.forename: Kátia
authors.initials: K
authors.lastname: Brandt
authors.forename: Carla R
authors.initials: CR
authors.lastname: Taddei
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Takagi
authors.forename: Fernanda F
authors.initials: FF
authors.lastname: Oliveira
authors.forename: Rubens T D
authors.initials: RT
authors.lastname: Duarte
authors.forename: Isabel
authors.initials: I
authors.lastname: Irino
authors.forename: Marina B
authors.initials: MB
authors.lastname: Martinez
authors.forename: Magda
authors.initials: M
authors.lastname: Carneiro-Sampaio
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D001644:Bifidobacterium / Q000235:genetics / Q000302:isolation & purification; D001938:Brazil; D001942:Breast Feeding; D003013:Clostridium / Q000235:genetics / Q000302:isolation & purification; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007422:Intestines / Q000382:microbiology*; D008297:Male; D011203:Poverty; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013210:Staphylococcus / Q000235:genetics / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S