Malaluang Pongpreecha, Wilén Elin, Lindahl Johanna, Hansson Ingrid, Morrell Jane M
Clinical Sciences, Swedish University of Agricultural Sciences (SLU), Box 7054, SE-75007 Uppsala, Sweden.
Department of Biosciences, International Livestock Research Institute, P.O. Box 30709, Nairobi 00100, Kenya.
Animals (Basel). 2021 Oct 22;11(11):3035. doi: 10.3390/ani11113035.
Bacteria develop resistance to antibiotics following low-level "background" exposure to antimicrobial agents as well as from exposure at therapeutic levels during treatment for bacterial infections. In this review, we look specifically at antimicrobial resistance (AMR) in the equine reproductive tract and its possible origin, focusing particularly on antibiotics in semen extenders used in preparing semen doses for artificial insemination. Our review of the literature indicated that AMR in the equine uterus and vagina were reported worldwide in the last 20 years, in locations as diverse as Europe, India, and the United States. Bacteria colonizing the mucosa of the reproductive tract are transferred to semen during collection; further contamination of the semen may occur during processing, despite strict attention to hygiene at critical control points. These bacteria compete with spermatozoa for nutrients in the semen extender, producing metabolic byproducts and toxins that have a detrimental effect on sperm quality. Potential pathogens such as , , and may occasionally cause fertility issues in inseminated mares. Antibiotics are added during semen processing, according to legislation, to impede the growth of these microorganisms but may have a detrimental effect on sperm quality, depending on the antimicrobial agent and concentration used. However, this addition of antibiotics is counter to current recommendations on the prudent use of antibiotics, which recommend that antibiotics should be used only for therapeutic purposes and after establishing bacterial sensitivity. There is some evidence of resistance among bacteria found in semen samples. Potential alternatives to the addition of antibiotics are considered, especially physical removal separation of spermatozoa from bacteria. Suggestions for further research with colloid centrifugation are provided.
细菌在低水平“背景”接触抗菌剂以及在治疗细菌感染期间接受治疗水平的接触后会产生抗生素耐药性。在本综述中，我们特别关注马生殖道中的抗菌药物耐药性（AMR）及其可能的来源，尤其关注用于制备人工授精精液剂量的精液稀释剂中的抗生素。我们对文献的综述表明，在过去20年里，全球各地都报道了马子宫和阴道中的AMR，这些地方包括欧洲、印度和美国等。在采集精液时，定殖于生殖道黏膜的细菌会转移到精液中；尽管在关键控制点严格注意卫生，但在精液处理过程中仍可能发生进一步污染。这些细菌与精子争夺精液稀释剂中的营养物质，产生对精子质量有不利影响的代谢副产物和毒素。诸如[未提及具体细菌名称]等潜在病原体偶尔可能导致接受人工授精的母马出现生育问题。根据法规，在精液处理过程中会添加抗生素以抑制这些微生物的生长，但这可能会对精子质量产生不利影响，具体取决于所使用的抗菌剂和浓度。然而，添加抗生素与当前关于谨慎使用抗生素的建议相悖，该建议指出抗生素仅应用于治疗目的且要在确定细菌敏感性之后使用。在精液样本中发现的细菌存在耐药性的一些证据。人们考虑了添加抗生素的潜在替代方法，尤其是将精子与细菌进行物理分离。还提供了关于胶体离心进一步研究的建议。
