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1.
Bacteria are renowned for their ability to tolerate and adapt to a wide range of adverse environmental conditions. The primary mechanism that facilitates these adaptations is thought to be the capacity to form and maintain biofilms. Within a biofilm, bacteria become attached to a surface where they exist in complex communities which are able to interact with each other through intracellular communication and thus rapidly adapt to changing environments. The organisms within biofilms are notorious for their resistance towards the host immune response and antibacterial agents compared to their free-living planktonic counterparts. Consequently, biofilms are of significant importance to both clinical and veterinary science. However, although bacterial infections are widely reported in animals their association with biofilms is rarely discussed. The aim of this review is to look at the characteristics of biofilm infections in humans and to relate this knowledge to veterinary science in order to assess their relevance in this area.  相似文献   

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In contrast to mammalian therapeutics, the use of pharmaceutical substances is rather limited in fish. It is basically restricted to anaesthetic agents and anti-infective agents for parasitic and microbial diseases. Anaesthetic agents are used primarily in fish farm and laboratory settings to provide analgesia and immobilization of fish for minor procedures. The anti-infective agents are used for controlling disease and the choice of drug depends on efficacy, ease of application, human safety, target animal safety including stress to the fish, environmental impact, regulatory approval, costs, and implications for marketing the fish. In this article, the major drugs used in salmonids in North America and Europe will be reviewed and some insight into future directions for drug development and use for the salmonid industry will be introduced. The mechanisms of action, pharmacokinetics, side effects, and uses of the drugs are emphasized.  相似文献   

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Respiratory disease is a serious and significant health problem for the bovine industry. Classically, the clinical and research focus has been on the putative causative agents and conditions, and their interactions with host inflammatory cells, particularly alveolar macrophages and blood neutrophils. There is, currently, growing acceptance of the concept that blood platelets play a primary role in the inflammatory process. This review explores the implications of such pro-inflammatory activity, especially in the context of neutrophil-platelet interactions, and the species specificity of cellular responses. The relevance of these issues for the treatment and prevention of bovine respiratory disease is also discussed.  相似文献   

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甲壳素、壳聚糖及其在水产中的应用   总被引:6,自引:0,他引:6  
1881年法国人Herri从菌类中提取了一种类似纤维素的物质。由于该物质广泛存在于虾、蟹壳中,故称为甲壳素。甲壳素又名甲壳质、壳糖、几丁质、白色甲壳素等,学名为多聚已酰氨基葡萄糖。甲壳素分布广泛,在自然界中的含量仅次于纤维素,被称为是纤维素之外的第二大类天然高分子,它分布于  相似文献   

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Genetic control of residual variance offers opportunities to increase uniformity and resilience of livestock and aquaculture species. Improving uniformity and resilience of animals will improve health and welfare of animals and lead to more homogenous products. Our aims in this review were to summarize the current models and methods to study genetic control of residual variance, genetic parameters and genomic results for residual variance and discuss future research directions. Typically, the genetic coefficient of variation is high (median = 0.27; range 0–0.86) and the heritability of residual variance is low (median = 0.01; range 0–0.10). Higher heritabilities can be achieved when increasing the number of records per animal. Divergent selection experiments have supported the feasibility of selecting for high or low residual variance. Genomic studies have revealed associations in regions related to stress, including those from the heat shock protein family. Although the number of studies is growing, genetic control of residual variance is still poorly understood, but big data and genomics offer great opportunities.  相似文献   

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Wide and discriminate use of antibiotics has resulted in serious biological and ecological concerns, especially the emergence of antibiotic resistance. Probiotics, known as beneficial microbes, are being proposed as an effective and eco-friendly alternative to antibiotics. They were first applied in aquaculture species more than three decades ago, but considerable attention had been given only in the early 2000s. Probiotics are defined as live or dead, or even a component of the microorganisms that act under different modes of action in conferring beneficial effects to the host or to its environment. Several probiotics have been characterized and applied in fish and a number of them are of host origin. Unlike some disease control alternatives being adapted and proposed in aquaculture where actions are unilateral, the immense potential of probiotics lies on their multiple mechanisms in conferring benefits to the host fish and the rearing environment. The staggering number of probiotics papers in aquaculture highlights the multitude of advantages from these microorganisms and conspicuously position them in the dynamic search for health-promoting alternatives for cultured fish. This paper provides an update on the use of probiotics in finfish aquaculture, particularly focusing on their modes of action. It explores the contemporary understanding of their spatial and nutritional competitiveness, inhibitory metabolites, environmental modification capability, immunomodulatory potential and stress-alleviating mechanism. This timely update affirms the importance of probiotics in fostering sustainable approaches in aquaculture and provides avenues in furthering its research and development.  相似文献   

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国内外循环式工厂化水产养殖模式研究进展   总被引:1,自引:0,他引:1  
《饲料工业》2017,(6):61-64
面对日趋严峻的水产食品安全、养殖生态安全以及生产过程安全,传统水产养殖发展模式正面临重大挑战。循环式工厂化水产养殖作为一种新型高效现代养殖模式,以水的综合循环利用为主要特征,成为水产养殖可持续发展的方向和研究的热点。尽管我国工厂化水产养殖模式的发展较为迅速,但与国外发达国家比较仍有较大差距。鉴于此,文章以工厂化水产养殖模式的发展历程为主线,结合近几年国内外的发展现状,在总结国外先进的养殖模式关键共性技术基础上,剖析了我国目前存在的突出问题并提出了相应的完善建议,旨在为环境友好的水产养殖业全产业链提供必要的技术支撑。  相似文献   

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Wound healing describes the host mechanisms involved in the process of restoring the continuity of tissues after injury. Wound healing progresses through a continuum of overlapping stages characterized by macroscopic, microscopic, and biochemical events. An understanding of the relation between these events can enhance clinicians' skills in wound management.  相似文献   

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Cyanides and their toxicity: A literature review   总被引:1,自引:0,他引:1  
Summary Cyanide is a potent and rapidly-acting asphyxiant which prevents tissue utilization of oxygen by inhibition of the cellular respiratory enzyme, cytochrome oxidase. Inhalation or ingestion of cyanide produces reactions within a few seconds and death within minutes. Cyanide toxicity of dietary origin has been implicated in acute animal deaths and as major etiologic factors in toxic ataxic neuropathy in man and as a cause of vision failure in humans suffering from tobacco amblyopia and leber's hereditary optic atrophy. Diagnosis of cyanide toxicity may be confirmed by a variety of laboratory procedures, but accurate assay is essential for proper conclusions from analysis of animal tissues several hours after death or from human samples in instances of chronic dietary exposure. Biological detoxification of cyanide is available through several routes, and the application of sodium nitrite with sodium thiosulfate or administration of methylene blue are effective treatment procedure. The environmental availability of cyanide in its various forms necessitates an understanding of its pathophysiology and responsible management of hazardous situations.  相似文献   

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Summary

Cyanide is a potent and rapidly‐acting asphyxiant which prevents tissue utilization of oxygen by inhibition of the cellular respiratory enzyme, cytochrome oxidase. Inhalation or ingestion of cyanide produces reactions within a few seconds and death within minutes. Cyanide toxicity of dietary origin has been implicated in acute animal deaths and as major etiologic factors in toxic ataxic neuropathy in man and as a cause of vision failure in humans suffering from tobacco amblyopia and leber's hereditary optic atrophy. Diagnosis of cyanide toxicity may be confirmed by a variety of laboratory procedures, but accurate assay is essential for proper conclusions from analysis of animal tissues several hours after death or from human samples in instances of chronic dietary exposure. Biological detoxification of cyanide is available through several routes, and the application of sodium nitrite with sodium thiosulfate or administration of methylene blue are effective treatment procedure. The environmental availability of cyanide in its various forms necessitates an understanding of its pathophysiology and responsible management of hazardous situations.  相似文献   

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Cancer is one of the most common causes of death in dogs. The availability of multiple treatment modalities and novel therapeutic targets make the correct diagnosis, prognostic stratification, and the identification of treatment effect predictive factors an issue of major debate in cancer management. Selection of high and low risk patients and the type of systemic or local treatment is important in cancer management. The search for better prognostic markers and predictive factors is now focused on the molecular mechanisms which underlie tumour behaviour, such as altered cell cycle progression, proliferation, apoptosis, and angiogenesis. The ultimate goal is to identify reliable markers that can accurately diagnose and stage a tumour and predict tumour's clinical behaviour, prognosis and response to therapy. In this review, the current state of prognostication in canine tumours and promising new molecular markers are discussed. The markers are allocated to four groups according to their function: (i) proliferation markers, (ii) apoptosis, (iii) extracellular matrix and cell adhesion molecules, (iv) angiogenesis and (v) cell cycle regulators. Clinicopathological factors and histopathological grading remain the most practical parameters in decision-making. Although experimental research has shown that molecular markers have a good potential to be used as diagnostic, prognostic or predictive markers in canine tumours, insufficient evidence exists on their efficacy for routine use in veterinary oncology.  相似文献   

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The possession of common antigens by three trematode parasites which commonly occur together in ruminants in the tropics, Fasciola gigantica, Dicrocoelium hospes and Schistosoma bovis was studied in relation to the reliability of serodiagnosis of infection with these helminths. The crude antigenic extracts of the three trematodes were subjected to Sephacryl S-300 column chromatography and F. gigantica was fractionated into six peaks, S. bovis into nine peaks and D. hospes into seven peaks. Common antigens were found in these three trematodes in both the crude whole worm antigenic extracts and in the semi-purified fractions obtained by Sephacryl S-300 column chromatography. The implications of this finding and the limitation it imposes on the usefulness of serodiagnostic tests in routine use as regards their specificity are discussed in relation to previous studies.  相似文献   

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Losses in livestock production due to ectoparasite infestations exceed $2.26 billion annually. Over 50 species of ectoparasites infest cattle throughout the United States. The horn fly, Haematobia irritans (L.), is the most important and widespread of the five to six major pest species of pastured cattle in the southern region. Results from the examination of production traits from cattle under ectoparasite burdens have been variable, ranging from no effect to significant reductions in weight gains. Because of this inconsistency, specific physiological and nutritional responses in cattle infested or not infested with horn flies have been examined. Data have shown significant differences in nitrogen retention, blood cortisol concentrations, vital signs, water consumption, and urine production. Implications are that total energy balance is altered when an animal is exposed to ectoparasite infestations, thereby resulting in decreased productivity.  相似文献   

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