Tvrdá Eva, Kačániová Miroslava, Baláži Andrej, Vašíček Jaromír, Vozaf Jakub, Jurčík Rastislav, Ďuračka Michal, Žiarovská Jana, Kováč Ján, Chrenek Peter
Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture, Tr. A. Hlinku 2, 94976 Nitra, Slovakia.
Institute of Horticulture, Faculty of Horticulture and Landscape Engineering, Slovak University of Agriculture, Tr. A. Hlinku 2, 94976 Nitra, Slovakia.
Animals (Basel). 2021 Dec 28;12(1):54. doi: 10.3390/ani12010054.
Bacterial contamination of semen is an often overlooked, yet important, factor contributing to decreased sperm vitality. Understanding the impact of bacterial presence on sperm structural integrity and functional activity may assist the development of effective strategies to prevent, or manage, bacteriospermia in the breeding practice. The aim of this study was to describe the bacterial profiles of ram semen ( = 35), and we also focused on the associations between bacteriospermia, sperm structure, and function, as well as oxidative and inflammatory characteristics of semen. For a better insight, the samples were divided into three groups, according to the breeds used in the study: native Wallachian (NW), improved Wallachian (IW), and Slovak dairy (SD) breeds. The results showed a significantly lower motility and membrane integrity in the NW group in comparison to the IW and SD groups, which was accompanied by a significantly higher concentration of leukocytes, increased reactive oxygen species (ROS) generation, and subsequent oxidative insults to the sperm lipids and proteins. Accordingly, the NW group presented with the highest bacterial load, in which and were the predominant representatives. The Pearson correlation analysis uncovered positive relationships amongst the bacterial load and leukocytospermia (r = 0.613), the extent of lipid peroxidation (r = 0.598), protein oxidation (r = 0.514), and DNA fragmentation (r = 0.638). Furthermore, positive correlations were found between the bacterial load and pro-inflammatory molecules, such as the C-reactive protein (r = 0.592), interleukin 1 (r = 0.709), and interleukin 6 (r = 0.474), indicating a possible involvement of the immune response in the process of bacteriospermia. Overall, our data indicate that ram semen quality may be equally affected by the bacterial load and diversity. Furthermore, we can assume that the presence of bacteria in ejaculates triggers inflammatory processes, causes ROS overproduction, and, thereby, contributes to alterations in the sperm structure, while at the same time compromising the fertilization ability of male gametes.
精液的细菌污染是一个常常被忽视但却很重要的导致精子活力下降的因素。了解细菌存在对精子结构完整性和功能活性的影响，可能有助于制定有效的策略，以预防或管理繁殖实践中的细菌性精液症。本研究的目的是描述公羊精液（n = 35）的细菌谱，同时我们还关注细菌性精液症、精子结构和功能之间的关联，以及精液的氧化和炎症特征。为了更深入了解，根据研究中使用的品种将样本分为三组：本地瓦拉几亚（NW）、改良瓦拉几亚（IW）和斯洛伐克奶牛（SD）品种。结果显示，与IW组和SD组相比，NW组的精子活力和膜完整性显著降低，同时白细胞浓度显著升高，活性氧（ROS）生成增加，随后精子脂质和蛋白质受到氧化损伤。因此，NW组的细菌载量最高，其中葡萄球菌和链球菌是主要代表。Pearson相关分析发现细菌载量与白细胞精子症（r = 0.613）、脂质过氧化程度（r = 0.598）、蛋白质氧化（r = 0.514）和DNA碎片化（r = 0.638）之间呈正相关。此外，还发现细菌载量与促炎分子如C反应蛋白（r = 0.592）、白细胞介素1（r = 0.709）和白细胞介素6（r = 0.474）之间呈正相关，表明免疫反应可能参与了细菌性精液症的过程。总体而言，我们的数据表明，公羊精液质量可能同样受到细菌载量和多样性的影响。此外，我们可以假设射精中细菌的存在会引发炎症过程，导致ROS过度产生，从而导致精子结构改变，同时损害雄配子的受精能力。
