339. THE RELATIONSHIP BETWEEN DNA FRAGMENTATION IN MOUSE OOCYTES AND GENITAL TRACT MICROORGANISMS
J. E. Harris A , E. S. Pelzer A , J. A. Allan B , E. Whiteside A , L. De Boer A and C. L. Knox AA Cell and Molecular Biosciences, Institute of Health and Biomedical Innovation, Kelvin Grove, QLD, Australia.
B The Wesley Hospital, Wesley Monash IVF, Brisbane, QLD, Australia.
Reproduction, Fertility and Development 22(9) 139-139 https://doi.org/10.1071/SRB10Abs339
Published: 6 September 2010
Abstract
Colonising bacteria detected within the follicular fluid of women undergoing assisted reproductive technology cycles has been associated with decreased embryo transfer rates and decreased pregnancy rates. The bacteria isolated from the follicular fluid of these women, at the time of trans-vaginal oocyte retrieval include Gram-positive anaerobic rods, Gram-negative anaerobic rods, streptococci, staphylococci, and lactobacilli. Some of these bacteria are opportunistic pathogens in the female genital tract. The expression of virulence factors including hyaluronidase and DNase, could affect the structural integrity of the oocyte and induce DNA fragmentation and apoptosis. Hyaluronin is a major carbohydrate component of the cumulus oocyte complex that could be a target for bacterial hyaluronidase. Other virulence factors associated with bacteria detected in cases of genital tract infections include the hydrolytic enzymes sialidase, β-galactosidase and β-N-acetylhexosaminidase (Howe 1999). Production of reactive oxygen species as a result of the presence of bacteria and bacterial heat shock proteins have been suggested as mechanisms responsible for increased DNA fragmentation and apoptotic progression of male gametes in colonised semen. Previous studies have not confirmed a direct relationship between sperm morphology and the level of sperm DNA fragmentation. DNA fragmentation in oocytes in relation to the presence of bacteria remains to be investigated. Oocyte quality is only determined by the assessment of cumulus cell morphology prior to in-vitro fertilisation. In-vitro testing of oocyte DNA integrity under various conditions may further the understanding of oocyte quality. In this study, mouse oocytes were used to investigate the structural and DNA integrity of oocytes after in vitro exposure to Lactobacillus spp., Streptococcus spp., and Staphylococcus spp. and determine whether the morphological appearance of the oocyte was predictive of the level of DNA fragmentation and whether DNA fragmentation can be attributed to certain bacterial species found colonising follicular fluid.
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