title: Prospective assessment of the gastroesophageal microbiome in VLBW neonates.
abstract: BACKGROUND
  The distal GI microbiota of hospitalized preterm neonates has been established to be unique from that of healthy full-term infants; the proximal GI, more specifically gastroesophageal colonization has not been systematically addressed. We prospectively evaluated early colonization of gastroesophageal portion of the GI tract of VLBW infants.
  
  
  METHODS
  This study involved 12 infants admitted to a level III NICU with gestational age (GA) 27 +/- 0.5 weeks and birth weight 1105 +/- 77 grams. The gastroesophageal microbial flora was evaluated using 16S rDNA analysis of aspirates collected in a sterile manner during the first 28 days of life.
  
  
  RESULTS
  Bacteria were detected in 9 of the 12 neonates. Ureaplasma was the dominant species in the first week of life, however, staphylococci were the predominant bacteria overall. By the fourth week, Gram (-) bacteria increased in abundance to account for 50% of the total organisms. Firmicutes were present in the majority of the neonates and persisted throughout the 4 weeks comprising nearly half of the sequenced clones. Noticeably, only two distinct species of Staphylococcus epidermidis were found, suggesting acquisition from the environment.
  
  
  CONCLUSIONS
  In our neonates, the esophagus and stomach environment changed from being relatively sterile at birth to becoming colonized by a phylogenetically diverse microbiota of low individual complexity. By the fourth week, we found predominance of Firmicutes and Proteobacteria. Bacteria from both phyla (CONS and Gram (-) organisms) are strongly implicated as causes of hospital-acquired infections (HAI). Evaluation of the measures preventing colonization with potentially pathogenic and pathogenic microorganisms from the hospital environment may be warranted and may suggest novel approaches to improving quality in neonatal care.
authors.affiliation: Department of Pediatrics, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA. vladana.milisavljevic@cshs.org
authors.forename: Vladana
authors.initials: V
authors.lastname: Milisavljevic
authors.forename: Meena
authors.initials: M
authors.lastname: Garg
authors.forename: Ivan
authors.initials: I
authors.lastname: Vuletic
authors.forename: Jeff F
authors.initials: JF
authors.lastname: Miller
authors.forename: Lauren
authors.initials: L
authors.lastname: Kim
authors.forename: Tina D
authors.initials: TD
authors.lastname: Cunningham
authors.forename: Imke
authors.initials: I
authors.lastname: Schröder
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis; D004947:Esophagus / Q000382:microbiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D007363:Intensive Care Units, Neonatal; D008297:Male; D054892:Metagenome; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012336:RNA, Ribosomal, 16S; D013270:Stomach / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
references.citation: Pediatr Infect Dis J. 1990 Feb;9(2):88-91
references.pmid: 2314957
references.citation: BMC Infect Dis. 2009 Sep 01;9:146
references.pmid: 19723318
references.citation: PLoS Biol. 2007 Jul;5(7):e177
references.pmid: 17594176
references.citation: Am J Dis Child. 1990 Mar;144(3):324-9
references.pmid: 2305739
references.citation: Early Hum Dev. 2010 Jul;86 Suppl 1:67-71
references.pmid: 20116944
references.citation: Arch Dis Child Fetal Neonatal Ed. 2009 Jan;94(1):F17-22
references.pmid: 18676413
references.citation: J Pediatr Surg. 2002 Jul;37(7):1011-2
references.pmid: 12077760
references.citation: Pediatrics. 1996 Sep;98(3 Pt 1):357-61
references.pmid: 8784356
references.citation: J Pediatr. 2011 Mar;158(3):390-6
references.pmid: 20961563
references.citation: J Clin Microbiol. 2003 Jul;41(7):3051-5
references.pmid: 12843042
references.citation: Infect Control Hosp Epidemiol. 2008 Nov;29(11):996-1011
references.pmid: 18947320
references.citation: Nutrition. 2008 Jul-Aug;24(7-8):632-7
references.pmid: 18486450
references.citation: JAMA. 1987 Nov 13;258(18):2548-52
references.pmid: 3669225
references.citation: J Immunol. 2004 Oct 1;173(7):4627-34
references.pmid: 15383597
references.citation: Pediatr Res. 2003 Sep;54(3):393-9
references.pmid: 12788986
references.citation: Int J Food Microbiol. 2009 Dec 31;136(2):227-31
references.pmid: 19720416
references.citation: Anaerobe. 2010 Aug;16(4):362-70
references.pmid: 20541022
references.citation: Pediatrics. 2002 Aug;110(2 Pt 1):285-91
references.pmid: 12165580
references.citation: J Matern Fetal Neonatal Med. 2011 Jan;24(1):47-50
references.pmid: 20504068
references.citation: J Clin Microbiol. 1996 Oct;34(10):2506-10
references.pmid: 8880510
references.citation: J Nutr. 2000 Feb;130(2S Suppl):432S-436S
references.pmid: 10721921
references.citation: Proc Natl Acad Sci U S A. 2011 Jan 18;108(3):1128-33
references.pmid: 21191099
references.citation: J Pediatr Surg. 2002 Aug;37(8):1177-82
references.pmid: 12149697