Ability of Ureaplasma parvum to invade mouse sperm, fertilize eggs through infected sperm, and impair mouse sperm function and embryo development

Gamete Biology

VOLUME 2, ISSUE 1, P13-23, FEBRUARY 01, 2021


Kazutoshi Ito, M.D., Kazuki Akai, M.Sc., Fumiko Nishiumi, Ph.D., Yukiko Nakura, B.E., Heng Ning Wu, Ph.D., Teru Kurata, B.E., Akira Onodera, Ph.D., Yuichi Kawai, Ph.D., Shinichiro Kajiyama, Ph.D., Itaru Yanagihara, M.D., Ph.D. 



To examine the effect of Ureaplasma parvum (U. parvum) infection on mouse sperm motility, structure, and fertilizing ability and on embryo development.


In vitro model of the effects of U. parvum serovar 3 infection on mouse sperm.


Basic research laboratory.





Main Outcome Measure(s)

Mouse sperm motility was examined using the swim-up method, and their motility parameters were analyzed using the sperm motility analysis system. Localization and invasion of U. parvum were observed with fluorescence, confocal, and scanning electron microscopy. After in vitro fertilization with U. parvum–infected sperm, the quality of the fertilized egg and embryo development were assessed.


U. parvum was attached and internalized into mouse sperms and localized mainly at the sperm head and midpiece. U. parvum–infected mouse sperms exhibited decreased motility in a dose- and duration-dependent manner. Electron micrographs revealed that U. parvum infection induced the aggregation and morphological destruction of mouse sperm. Infected mouse sperm transported U. parvum into the fertilized egg with reduced fertilization rates, and infected embryo development was impaired.


U. parvum infection caused deterioration of the mouse sperm quality and its functions, which affected the fertilization rate and embryo development.