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.
J Reprod Immunol. 2013 Sep;99(1-2):69-79. doi: 10.1016/j.jri.2013.07.004. Epub 2013 Aug 8.
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.
最近我们报道了在卵泡液中存在细菌。先前的研究报告称，人类精子在体内或体外与细菌孵育后，精子 DNA 碎片化会导致早期胚胎死亡和妊娠率降低，但细菌对卵子的影响尚不清楚。本研究检查了在人类卵泡液中孵育 12 小时后的小鼠卵母细胞内的 DNA（n=5），这些卵泡液是从接受体外受精（IVF）治疗的女性中收集的。对每个卵泡液样本进行培养以检测细菌的存在。末端脱氧核苷酸转移酶介导的 dUTP 缺口末端标记（TUNEL）用于标记在体外孵育在人类卵泡液中的排卵但未受精的小鼠卵母细胞中的 DNA 碎片化。在卵泡液中检测到细菌酿脓链球菌和消化链球菌属（低剂量）、加氏乳杆菌（高剂量）、粪肠球菌或痤疮丙酸杆菌。在含有 P. acnes 或 L. gasseri（高剂量）的卵泡液中孵育的卵母细胞中观察到最严重的 DNA 碎片化。在含有低剂量 L. gasseri 或 E. faecalis 的卵泡液中孵育的小鼠卵母细胞中未观察到 DNA 碎片化。人类卵母细胞受精率低（<29%）与小鼠卵母细胞中广泛的碎片化（80-100%）相关。体内定植于人类卵泡液的细菌可能导致体外孵育 12 小时后的小鼠卵母细胞 DNA 碎片化。卵泡液细菌可能导致卵母细胞和/或胚胎质量差，从而导致 IVF 结局不佳。
