Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, 999 Phuttamonthon 4 Rd., Salaya, Phuttamonthon, Nakhon Pathom, 73170, Thailand.
Laboratory of Bacteria, Veterinary Diagnostic Center, Faculty of Veterinary Science, Mahidol University, 999 Phuttamonthon 4 Rd., Salaya, Phuttamonthon, Nakhon Pathom, 73170, Thailand.
Sci Rep. 2023 Apr 12;13(1):5995. doi: 10.1038/s41598-023-33062-w.
The use of antibiotics with semen extender appears to be a practical solution to minimise bacterial growth in fresh boar semen preservation. Unfortunately, the excessive use of antibiotics promotes antimicrobial resistance (AMR). This becomes a worldwide concern due to the antimicrobial resistance genes transmitted to animals, environment, and humans. Probiotics are one of the alternative methods to reduce antibiotic use. They could inhibit pathogenic bacteria by producing antimicrobial substances in cell free supernatants (CFS). Nevertheless, there is no comprehensive study undertaken on inhibitory activity against pathogenic bacteria isolated from boar semen origin. Our study investigated the efficacy of CFS produced from selected probiotics: Bacillus spp., Enterococcus spp., Weissella spp., Lactobacillus spp., and Pediococcus spp. inhibiting pathogenic bacteria isolated from fresh boar semen. Besides, the semen-origin pathogenic bacteria are subjected to identification, antimicrobial resistance genes detection, and antibiotic susceptibility test (AST). Pseudomonas aeruginosa, Escherichia coli, and Proteus mirabilis are the most common pathogens identified in boar semen with resistance to numerous antibiotics used in pig industry. The CFS with its antimicrobial peptides and/or bacteriocin constituent derived from selected probiotics could inhibit the growth of pathogenic bacteria carrying antimicrobial resistance genes (mcr-3 and int1 genes). The inhibition zones for Pseudomonas aeruginosa, Escherichia coli, and Proteus mirabilis provided more efficient results in the CFS derived from Lactobacillus spp. and Pediococcus spp. than those of the CFS produced from Enterococcus spp., Weissella spp. and Bacillus spp., respectively. It is worth noted that as the incubation time increased, the antibacterial activity decreased conversely. Our results on CFS with its antimicrobial peptides and/or bacteriocin constituent inhibits semen-origin pathogenic bacteria guide the direction as a promising alternative method used in the semen extender preservation of the pig industry.
在新鲜公猪精液保存中，使用抗生素与精液稀释液结合似乎是减少细菌生长的实用方法。不幸的是，抗生素的过度使用会促进抗菌药物耐药性（AMR）的产生。由于抗菌药物耐药基因传播到动物、环境和人类，这已成为一个全球性的关注点。益生菌是减少抗生素使用的替代方法之一。它们可以通过在无细胞上清液（CFS）中产生抗菌物质来抑制病原菌。然而，目前还没有针对从公猪精液中分离出的病原菌进行抑制活性的综合研究。我们的研究调查了从选定的益生菌（芽孢杆菌属、肠球菌属、魏斯氏菌属、乳杆菌属和明串珠菌属）产生的 CFS 抑制从新鲜公猪精液中分离出的病原菌的功效。此外，对来自精液的病原菌进行鉴定、抗菌药物耐药基因检测和抗生素敏感性试验（AST）。铜绿假单胞菌、大肠杆菌和奇异变形杆菌是从公猪精液中分离出的最常见的病原菌，对猪业中使用的许多抗生素均有耐药性。来自选定益生菌的 CFS 及其抗菌肽和/或细菌素成分可以抑制携带抗菌药物耐药基因（mcr-3 和 int1 基因）的病原菌的生长。来自乳杆菌属和明串珠菌属的 CFS 对铜绿假单胞菌、大肠杆菌和奇异变形杆菌的抑制区比来自肠球菌属、魏斯氏菌属和芽孢杆菌属的 CFS 更有效。值得注意的是，随着孵育时间的增加，抗菌活性反而降低。我们关于 CFS 及其抗菌肽和/或细菌素成分抑制精液来源病原菌的结果为猪业精液稀释液保存中使用这种有前景的替代方法提供了指导方向。
