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- Hemberg, Elisabeth, et al.
(författare)
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Microbial Profiling of Amniotic Fluid, Umbilical Blood and Placenta of the Foaling Mare
- 2023
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Ingår i: Animals. - : MDPI. - 2076-2615. ; 13:12
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Tidskriftsartikel (refereegranskat)abstract
- Simple Summary Although previously the placenta was assumed to be sterile, with microbes only being present in association with pathology, recent studies have suggested that this assumption may not be correct. Some researchers argue for the presence of a microbial community in the placenta, which is important to help the foal to adapt to life outside the uterus. Therefore, we examined the placenta, amniotic fluid and umbilical blood of 24 foaling mares, as well as jugular blood from the foals. All of the mares and foals were healthy, and foaling was normal. Some bacterial growth was isolated in most of the umbilical blood samples. Bacterial DNA was extracted and sequenced from placental samples. The most abundant phyla were Proteobacteria (approximately 44%) and Actinobacteria (approximately 28%). In conclusion, bacteria were found in the fetal compartments and placenta of healthy equine pregnancies, perhaps lending support to the theory that the placenta has its own bacterial community. The presence of a microbiome/microbiota in the placenta is hotly debated. In previous studies, the presence of bacteria in equine amniotic fluid and umbilical blood was independent of foal health. The objective of the present study was to determine if the same bacteria are present in the equine placenta as in amniotic fluid and umbilical blood. Samples were obtained from 24 parturient mares and foals. Placental bacterial DNA was extracted, and the microbiome was identified using 16S rRNA sequencing. All amniotic fluid samples contained some polymorphonucleocytes; bacteria were isolated from four samples. Aerobic or anaerobic growth was found in 18 and 3 umbilical blood samples, respectively. Serum amyloid A was <5 mg/L in all 24 samples, total WBC varied between 2900 and 10,700/& mu;L, and fibrinogen varied between 0 and 5.16 g/L. In jugular blood, serum amyloid A was <5 mg/L in all 24 foals, total white blood count was 3200 to 8100/& mu;L, and fibrinogen was 0.44 to 4.42 g/L. The diversity of bacterial microbiota was similar in all placental regions at the phylum level but differed at the genus level; the most abundant phyla were Proteobacteria (42-46.26%) and Actinobacteria (26.91-29.96%). In conclusion, bacteria were found in the fetal compartments and placenta of healthy equine pregnancies; however, we can neither prove nor disprove the hypothesis that the placenta has its own microbiome.
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- Malaluang, Pongpreecha, et al.
(författare)
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Antimicrobial Resistance in Equine Reproduction
- 2021
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Ingår i: Animals. - : MDPI. - 2076-2615. ; 11:11
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Forskningsöversikt (refereegranskat)abstract
- Simple SummaryBacteria can develop resistance to antibiotics, resulting in the appearance of infections that are difficult or impossible to treat. This ability enables bacteria to survive in hostile environments and can result from exposure to even small amounts of antibiotic substances. Bacteria are present in the reproductive tract of the horse; they can develop resistance to antibiotics, because the animal has been treated for an infection, or due to insemination with a semen dose that contains antibiotics. Bacteria colonize the membrane lining the male reproductive tract and are transferred to the semen during collection. They can cause sperm quality to deteriorate during storage or may cause an infection in the mare. Therefore, antibiotics are added to the semen dose, according to legislation. However, these antibiotics may contribute to the development of resistance. Current recommendations are that antibiotics should only be used to treat bacterial infections and where the sensitivity of the bacterium to the antibiotic has first been established. Therefore, adding antibiotics to semen extenders does not fit these recommendations. In this review, we examine the effects of bacteria in semen and in the inseminated mare, and possible alternatives to their use.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 Klebsiella pneumoniae, Escherichia coli, and Pseudomonas aeruginosa 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.
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- Munoz-Fuentes, Violeta, et al.
(författare)
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Strong Artificial Selection in Domestic Mammals Did Not Result in an Increased Recombination Rate
- 2015
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 32:2, s. 510-523
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Tidskriftsartikel (refereegranskat)abstract
- Recombination rates vary in intensity and location at the species, individual, sex and chromosome levels. Despite the fundamental biological importance of this process, the selective forces that operate to shape recombination rate and patterns are unclear. Domestication offers a unique opportunity to study the interplay between recombination and selection. In domesticates, intense selection for particular traits is imposed on small populations over many generations, resulting in organisms that differ, sometimes dramatically, in morphology and physiology from their wild ancestor. Although earlier studies suggested increased recombination rate in domesticates, a formal comparison of recombination rates between domestic mammals and their wild congeners was missing. In order to determine broad-scale recombination rate, we used immunolabeling detection of MLH1 foci as crossover markers in spermatocytes in three pairs of closely related wild and domestic species (dog and wolf, goat and ibex, and sheep and mouflon). In the three pairs, and contrary to previous suggestions, our data show that contemporary recombination rate is higher in the wild species. Subsequently, we inferred recombination breakpoints in sequence data for 16 genomic regions in dogs and wolves, each containing a locus associated with a dog phenotype potentially under selection during domestication. No difference in the number and distribution of recombination breakpoints was found between dogs and wolves. We conclude that our data indicate that strong directional selection did not result in changes in recombination in domestic mammals, and that both upper and lower bounds for crossover rates may be tightly regulated.
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- Abraham, Maria Celina, et al.
(författare)
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Testicular length as an indicator of the onset of sperm production in alpacas under Swedish conditions
- 2016
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Ingår i: Acta Veterinaria Scandinavica. - : Springer Science and Business Media LLC. - 0044-605X .- 1751-0147. ; 58
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Tidskriftsartikel (refereegranskat)abstract
- Background The popularity of alpacas (Vicugna pacos) is increasing in Sweden as well as in other countries; however, knowledge about optimal management practices under Swedish conditions is still limited. The wide age range reported when the onset of puberty can occur, between 1 and 3years of age, makes management decisions difficult and may be influenced by the conditions under which the alpacas are kept. The aim of this study was to find out when Swedish alpacas can be expected to start producing sperm, by using testicular length and body condition score as a more precise indirect indicator than age. Results This study suggests that animals with a testicular length ≥3.8cm would be producing sperm; however, if it is crucial to know that there is no sperm production for management purposes, the threshold level for testicular length used to differentiate between sperm-producing and non-sperm producing animals should be ≤1.6cm instead. If only one variable is considered, testicular length appears to better than age alone to predict sperm production. Body condition score together with testicular length explains the individual onset of puberty and better guide management recommendations. Conclusions Using a combination of these parameters (testicular length, body condition score and age) as a tool for decision making for alpaca husbandry under Swedish conditions is suggested.
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