title: TUNEL analysis of DNA fragmentation in mouse unfertilized oocytes: the effect of microorganisms within human follicular fluid collected during IVF cycles.
abstract: Recently we reported the presence of bacteria within follicular fluid. Previous studies have reported that DNA fragmentation in human spermatozoa after in vivo or in vitro incubation with bacteria results in early embryo demise and a reduced rate of ongoing pregnancy, but the effect of bacteria on oocytes is unknown. This study examined the DNA within mouse oocytes after 12 hours' incubation within human follicular fluids (n=5), which were collected from women undergoing in vitro fertilization (IVF) treatment. Each follicular fluid sample was cultured to detect the presence of bacteria. Terminal deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL) was used to label DNA fragmentation in ovulated, non-fertilized mouse oocytes following in vitro incubation in human follicular fluid. The bacteria Streptococcus anginosus and Peptoniphilus spp., Lactobacillus gasseri (low-dose), L. gasseri (high-dose), Enterococcus faecalis, or Propionibacterium acnes were detected within the follicular fluids. The most severe DNA fragmentation was observed in oocytes incubated in the follicular fluids containing P. acnes or L. gasseri (high-dose). No DNA fragmentation was observed in the mouse oocytes incubated in the follicular fluid containing low-dose L. gasseri or E. faecalis. Low human oocyte fertilization rates (<29%) were associated with extensive fragmentation in mouse oocytes (80-100%). Bacteria colonizing human follicular fluid in vivo may cause DNA fragmentation in mouse oocytes following 12h of in vitro incubation. Follicular fluid bacteria may result in poor quality oocytes and/or embryos, leading to poor IVF outcomes.
authors: Institute of Health and Biomedical Innovation, Faculty of Science and Technology, Queensland University of Technology, Brisbane 4001, Queensland, Australia; The Wesley Research Institute, Women's Health Laboratory, The Wesley Hospital, P.O. Box 499, Toowong, Brisbane 4066, Queensland, Australia. Electronic address: epelzer@wesleyresearch.com.au.
authors: Elise S
authors: ES
authors: Pelzer
authors: Jessica E
authors: JE
authors: Harris
authors: John A
authors: JA
authors: Allan
authors: Mary A
authors: MA
authors: Waterhouse
authors: Tara
authors: T
authors: Ross
authors: Kenneth W
authors: KW
authors: Beagley
authors: Christine L
authors: CL
authors: Knox
mesh_terms: D000328:Adult; D000818:Animals; D001424:Bacterial Infections / Q000150:complications / Q000235:genetics / Q000382:microbiology*; D002478:Cells, Cultured; D053938:DNA Fragmentation; D004195:Disease Models, Animal; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D015571:Follicular Fluid / Q000378:metabolism / Q000382:microbiology*; D006801:Humans; D020287:In Situ Nick-End Labeling; D007247:Infertility, Female / Q000150:complications / Q000382:microbiology* / Q000628:therapy*; D051379:Mice; D009865:Oocytes / Q000378:metabolism* / Q000382:microbiology; D011247:Pregnancy; D016896:Treatment Outcome
keywords: Bacteria; DNA fragmentation; Follicular fluid; In vitro fertilization; Mouse oocytes