504 The presence of bacterial species in boar semen and their impact on the sperm quality and oxidative balance.

摘要

The loss sperm vitality and the occurence seminal oxidative stress may be associated with bacteriospermia, although most reports focus on causative agents of urogenital tract infections. Therefore, this study assessed whether bacteria detected in semen from healthy animals could also contribute to a decreased sperm quality. Ejaculates were collected from 36 clinically healthy Duroc breeding boars, and the presence of bacterial strains was assessed using MALDI-TOF Mass Spectrometry. Computer-assisted sperm analysis was used to evaluate the sperm motility, mitochondrial activity was evaluated using the JC-1 fluorescent dye and reactive oxygen species (ROS) production was investigated using luminol-based chemiluminescence. Seminal plasma was separeted and subjected to the assessment of the protein carbonyls (PC) and malondialdehyde (MDA) using colorimetric protocols. For the statistical analysis, the samples were distributed into groups depending on the bacterium identified, and subsequently subjected to One Way ANOVA and the Dunnet test using GraphPad Prism. MALDI-TOF detected 15 bacterial strains in 30 samples, among which , and were the prevalent genera. The presence of , and was associated with a significantly deceased sperm motility (P<0.001) and mitochondrial activity (P<0.01), followed by a significant increase of oxidative stress markers (P<0.001 in case of ROS and MDA, P<0.05 with respect to PC). Inversely, the presence of , and had no impact on the sperm quality, although semen positive for these bacteria exhibited a significantly higher ROS production and lipid peroxidation (P<0.05). Our results suggest that bacteria detectable in semen from healthy animals may exhibit the potential to decrease the sperm quality. As such, more attention must be paid to eliminate factors leading to bacteriospermia and its detrimental effects on semen quality in animal reproduction. This research was supported by the Slovak Research and Development Agency Grant no. APVV-15–0544.