title: Medical therapy reduces microbiota diversity and evenness in surgically recalcitrant chronic rhinosinusitis.
abstract: BACKGROUND
  Chronic rhinosinusitis (CRS) is a highly prevalent and heterogeneous condition frequently treated with antibiotics and corticosteroid therapy. However, the effect of medical therapy on sinus microbiota remains unknown.
  
  
  METHODS
  We enrolled CRS patients (n = 6) with patent maxillary antrostomies and active mucosal inflammation, who had not received antibiotics or corticosteroids in the previous 8 weeks. A pretreatment and posttreatment maxillary sinus swab was collected, from which DNA was extracted, pyrosequenced, and analyzed using a naïve Bayesian classifier and ecological analyses.
  
  
  RESULTS
  Four patients showed significant improvement in endoscopic appearance. The shifts in microbiota in response to therapy were highly individualized. There was no single common microbiota profile among patients with similar clinical outcomes, but overall there was significant decrease in microbiota diversity (t(5) = 2.05, p = 0.10) and evenness (t(5) = 2.28, p = 0.07) after treatment.
  
  
  CONCLUSIONS
  Our findings strongly correlate with earlier studies that examined the impact of antibiotics on human microbiota. We observed that posttreatment, patients frequently became colonized by taxa that are less susceptible to the prescribed antibiotics. Our findings highlight the challenge in seeking generalizable diagnostic and therapeutic options in CRS, particularly regarding microbiological response and outcomes.
authors.affiliation: Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ; Center for Microbiomics and Human Health, Translational Genomics Research Institute, Flagstaff, AZ; Department of Pathology, The Johns Hopkins School of Medicine, Baltimore, MD.
authors.forename: Cindy M
authors.initials: CM
authors.lastname: Liu
authors.forename: Katerina
authors.initials: K
authors.lastname: Soldanova
authors.forename: Lora
authors.initials: L
authors.lastname: Nordstrom
authors.forename: Michael G
authors.initials: MG
authors.lastname: Dwan
authors.forename: Owain L
authors.initials: OL
authors.lastname: Moss
authors.forename: Tania L
authors.initials: TL
authors.lastname: Contente-Cuomo
authors.forename: Paul
authors.initials: P
authors.lastname: Keim
authors.forename: Lance B
authors.initials: LB
authors.lastname: Price
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Lane
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002908:Chronic Disease; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004359:Drug Therapy, Combination; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D064307:Microbiota / Q000235:genetics*; D008875:Middle Aged; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012220:Rhinitis / Q000188:drug therapy* / Q000382:microbiology / Q000601:surgery; D017423:Sequence Analysis, RNA / Q000379:methods; D012852:Sinusitis / Q000188:drug therapy* / Q000382:microbiology / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D005938:Glucocorticoids; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D008775:Methylprednisolone
keywords: 16S rRNA gene; Microbiology; Sinusitis, eosinophilic rhinitis; chronic rhinosinusitis; maximum medical therapy; microbiome; microbiota; nasal polyposis