title: Dysbiosis of fecal microbiota in Crohn's disease patients as revealed by a custom phylogenetic microarray.
abstract: BACKGROUND
  A custom phylogenetic microarray composed of small subunit ribosomal RNA probes, representing ≈500 bacterial species from the human and animal gut, was developed and evaluated for analysis of gut microbial diversity using fecal samples from healthy subjects and Crohn's disease (CD) patients.
  
  
  METHODS
  Oligonucleotide probes (≈40 mer) used on the microarray were selected from published articles or designed with the "GoArray" microarray probe design program using selected bacterial 16S rRNA sequences. Fecal 16S rDNA from individual samples of six healthy subjects and six CD patients were used as template to generate fluorescently labeled cRNA that was hybridized to the microarray. Differences revealed by the microarray in relative abundance of microbial populations between healthy and diseased patients were verified using quantitative real-time polymerase chain reaction (PCR) with species-specific primer sets.
  
  
  RESULTS
  The microarray analyses showed that Eubacterium rectale, Bacteroides fragilis group, B. vulgatus, Ruminococcus albus, R. callidus, R. bromii, and Faecalibacterium prausnitzii were 5-10-fold more abundant in the healthy subjects than in the CD patients, while Enterococcus sp., Clostridium difficile, Escherichia coli, Shigella flexneri, and Listeria sp. were more abundant in the CD group.
  
  
  CONCLUSIONS
  The microarray detected differences in abundance of bacterial populations within the phylum Firmicutes that had been reported previously for the same samples based on phylogenetic analysis of metagenomic clone libraries. In addition, the microarray showed that Enterococcus sp. was in higher abundance in the CD patients. This microarray should be another useful tool to examine the diversity and abundance of human intestinal microbiota.
authors.affiliation: Preventative Health National Research Flagship, CSIRO, St. Lucia, Qld, Australia. kansbio@gmail.com
authors.forename: Seungha
authors.initials: S
authors.lastname: Kang
authors.forename: Stuart E
authors.initials: SE
authors.lastname: Denman
authors.forename: Mark
authors.initials: M
authors.lastname: Morrison
authors.forename: Zhongtang
authors.initials: Z
authors.lastname: Yu
authors.forename: Joel
authors.initials: J
authors.lastname: Dore
authors.forename: Marion
authors.initials: M
authors.lastname: Leclerc
authors.forename: Chris S
authors.initials: CS
authors.lastname: McSweeney
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D003424:Crohn Disease / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D005243:Feces / Q000382:microbiology*; D020869:Gene Expression Profiling; D006801:Humans; D007422:Intestines / Q000382:microbiology*; D054892:Metagenome / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D015345:Oligonucleotide Probes; D012333:RNA, Messenger / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D004269:DNA, Bacterial; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D012336:RNA, Ribosomal, 16S