Luther Anne-Marie, Nguyen Thu Quynh, Verspohl Jutta, Waberski Dagmar
Unit for Reproductive Medicine/Clinic for Pigs and Small Ruminants, University of Veterinary Medicine Hannover, Hannover, Germany.
Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Germany.
Front Vet Sci. 2023 Nov 21;10:1294903. doi: 10.3389/fvets.2023.1294903. eCollection 2023.
Facing the global threat of antimicrobial resistance, the reduction of antibiotic use in semen extenders is a main goal in artificial insemination (AI) of pigs. The aim of this study was to investigate the potential of a commercial extender containing an organic bactericidal supplement in the absence of conventional antibiotics to control bacterial growth and to maintain the quality of boar spermatozoa during long-term semen storage for up to 144 h at 17°C.
Semen from 233 boars housed at 16 European AI centers was split and diluted in the long-term extender "Androstar Plus without antibiotics + organic bactericidal supplement" (APlus) and in the control extender Beltsville Thawing Solution (BTS) with gentamicin, which is routinely used in many AI centers. Sperm motility was assessed with computer-assisted semen analysis (CASA) and membrane integrity was evaluated with flow cytometry. The number of bacteria was determined by counting colonies on agar plates.
At the end of storage, bacterial counts were ≥ 10 CFU/mL in 10.7% of the APlus and in 0.4% of the BTS samples. At the same time, bacterial counts were only weakly correlated with sperm motility ( = -0.23, < 0.05), and there was no correlation with sperm membrane integrity ( > 0.05). Among the 12 identified bacterial species in APlus samples, loss of sperm quality was exclusively observed in the presence of >10 CFU/mL and . Both these bacterial species, despite their known multi-drug resistance and the continuous use of gentamicin in Europe, proved sensitive to this antibiotic, thus indicating an efficient quality assurance program and responsible antibiotic use.
Long-term storage of boar semen at 17°C without conventional antibiotics in an extender containing an organic bactericidal supplement is an option if semen samples are regularly tested for the presence of and , and the source of contamination is eliminated.
面对全球抗菌药物耐药性的威胁，减少精液稀释液中抗生素的使用是猪人工授精（AI）的一个主要目标。本研究的目的是调查一种含有有机杀菌补充剂的商业稀释液在不含传统抗生素的情况下，在17°C下长期精液保存长达144小时期间控制细菌生长和维持公猪精子质量的潜力。
来自16个欧洲人工授精中心饲养的233头公猪的精液被分成两份，并分别用长期稀释液 “不含抗生素 + 有机杀菌补充剂的Androstar Plus”（APlus）和含有庆大霉素的对照稀释液Beltsville解冻液（BTS）进行稀释，BTS是许多人工授精中心常规使用的稀释液。用计算机辅助精液分析（CASA）评估精子活力，并用流式细胞术评估膜完整性。通过计算琼脂平板上的菌落数来确定细菌数量。
在保存结束时，APlus样本中有10.7%的细菌计数≥10 CFU/mL，BTS样本中有0.4%的细菌计数≥10 CFU/mL。同时，细菌计数与精子活力仅呈弱相关（r = -0.23，P < 0.05），与精子膜完整性无相关性（P > 0.05）。在APlus样本中鉴定出的12种细菌中，仅在存在>10 CFU/mL的 和 时观察到精子质量下降。尽管这两种细菌已知具有多重耐药性，且欧洲一直在持续使用庆大霉素，但它们对这种抗生素敏感，这表明了有效的质量保证计划和合理的抗生素使用。
如果定期检测精液样本中是否存在 和 ，并消除污染源，那么在含有有机杀菌补充剂的稀释液中于17°C下长期保存公猪精液而不使用传统抗生素是一种选择。
