title: Acute appendicitis in children is associated with an abundance of bacteria from the phylum Fusobacteria.
abstract: BACKGROUND
  Although luminal obstruction has traditionally been viewed as the underlying cause of appendicitis, recent evidence has suggested that the disease may result directly from invasion by specific pathogens, e.g. Fusobacterium nucleatum. The purpose of this study was to survey microbial communities within pediatric appendectomy specimens using a culture-independent approach.
  
  
  METHODS
  We performed 16S ribosomal gene sequence analysis to profile the microbiota present within luminal fluid obtained from 22 pediatric appendectomy specimens. These included 10 simple appendicitis cases, 5 perforated appendicitis cases, 2 interval appendectomies, and 5 incidental appendectomies.
  
  
  RESULTS
  Samples could be divided into 2 distinct clusters based upon the composition of the appendiceal bacterial communities. Appendicitis samples contained an increased abundance of Fusobacterium spp. and a reduced abundance of Bacteroides spp. relative to non-appendicitis cases. Appendicitis samples also contained variable amounts of other oral taxa such as Porphyromonas, Parvimonas, and Gemella, whereas these taxa were generally absent from non-appendicitis samples.
  
  
  CONCLUSIONS
  Acute appendicitis is associated with an abundance of Fusobacterium spp. and other pathogens commonly found in the oral cavity. Further research is needed to determine whether these organisms directly cause appendicitis or rather proliferate in the appendix as a secondary consequence of inflammation.
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Zhong
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Division of Pediatric Surgery, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Brower-Sinning
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Division of Pediatric Surgery, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA.
authors.forename: Brian
authors.initials: B
authors.lastname: Firek
authors.affiliation: Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA; Division of Pediatric Surgery, Children's Hospital of Pittsburgh, Pittsburgh, PA 15224, USA. Electronic address: Michael.morowitz@chp.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Morowitz
mesh_terms: D000293:Adolescent; D001062:Appendectomy; D001064:Appendicitis / Q000209:etiology / Q000382:microbiology* / Q000601:surgery; D001065:Appendix / Q000382:microbiology; D001439:Bacteroides / Q000302:isolation & purification; D001826:Body Fluids / Q000382:microbiology; D002648:Child; D002675:Child, Preschool; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004275:DNA, Ribosomal / Q000032:analysis / Q000235:genetics; D005673:Fusobacterium / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D064307:Microbiota; D009055:Mouth / Q000382:microbiology; D010865:Pilot Projects; D017861:Porphyromonas / Q000302:isolation & purification; D020560:Proteobacteria / Q000302:isolation & purification; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D021521:Ribotyping; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Appendicitis; Fusobacteria; Gut bacteria; Microbiome