title: Impact of a hormone-releasing intrauterine system on the vaginal microbiome: a prospective baboon model.
abstract: BACKGROUND
  Use of a levonorgestrel-releasing intrauterine system (LNG-IUS) in humans may alter vaginal microbial populations and susceptibility to pathogens. This study evaluated the time-dependent effects of an LNG-IUS on the vaginal microbiome of the baboon, a useful animal model for reproductive studies.
  
  
  METHODS
  Levonorgestrel-releasing intrauterine systems were inserted into three reproductively mature, female baboons. The animals were evaluated for 6 months by physical examination and Gram-stained cytology. The vaginal microbiota was characterized at each timepoint by culture-independent analysis of the 16S rRNA-encoding gene.
  
  
  RESULTS
  Each baboon harbored a diverse vaginal microbiome. Interindividual variation exceeded intra-individual variation. Diversity declined over time in one baboon and showed mild fluctuations in the other two. There were no significant community differences from early to late post-LNG-IUS placement.
  
  
  CONCLUSIONS
  The baboon vaginal microbiome is unique to each individual and is polymicrobial. In this pilot study, the vaginal microbiome remained stable from early to late post-LNG-IUS placement.
authors.affiliation: Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, MI, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Hashway
authors.forename: I L
authors.initials: IL
authors.lastname: Bergin
authors.forename: C M
authors.initials: CM
authors.lastname: Bassis
authors.forename: M
authors.initials: M
authors.lastname: Uchihashi
authors.forename: K C
authors.initials: KC
authors.lastname: Schmidt
authors.forename: V B
authors.initials: VB
authors.lastname: Young
authors.forename: D M
authors.initials: DM
authors.lastname: Aronoff
authors.forename: D L
authors.initials: DL
authors.lastname: Patton
authors.forename: J D
authors.initials: JD
authors.lastname: Bell
mesh_terms: D000818:Animals; D003271:Contraceptive Agents, Female / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D007436:Intrauterine Devices, Medicated; D016912:Levonorgestrel / Q000008:administration & dosage / Q000494:pharmacology*; D064307:Microbiota / Q000187:drug effects*; D023421:Models, Animal; D008969:Molecular Sequence Data; D048530:Papio anubis / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging; D014621:Vagina / Q000187:drug effects* / Q000382:microbiology*
chemical_list: D003271:Contraceptive Agents, Female; D012336:RNA, Ribosomal, 16S; D016912:Levonorgestrel
keywords: levonorgestrel; non-human primate; pyrosequencing