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1.
Specific immunoprophylaxis has played a key role in prevention and control of animal infectious diseases for many years. Vaccines are commonly used to diminish economic losses in animal production caused by infectious agents. Currently, respiratory diseases are the main health problem in cattle. BHV1, BRSV and BVD-MD viruses are among the most important pathogens worldwide. They can cause a disease themselves or they can be one of many agents causing a respiratory syndrome. The following article describes the specific immunoprophylaxis of cattle viral diseases caused by such viruses.  相似文献   

2.
病原体溯源技术研究进展及在寄生虫上的应用   总被引:1,自引:0,他引:1  
病原体是导致人和动植物感染疾病的根源,带来一系列的安全隐患。病原体溯源研究对于基因型鉴定、分类地位准确化、流行病学调查及疾病的防控具有重大意义。近年来,分子生物学技术已被广泛用于病原溯源研究。作者主要对病原体溯源技术的最新研究进展及其在寄生虫上的应用作一综述。  相似文献   

3.
This paper identifies some of the more important diseases at the wildlife-livestock interface and the role wildlife plays in disease transmission. Domestic livestock, wildlife and humans share many similar pathogens. Pathogens of wild or domestic animal origin that can cause infections in humans are known as zoonotic organisms and the converse are termed as anthroponotic organisms. Seventy-seven percent of livestock pathogens and 91% of domestic carnivore pathogens are known to infect multiple hosts, including wildlife. Understanding this group of pathogens is critical to public health safety, because they infect a wide range of hosts and are most likely to emerge as novel causes of infection in humans and domestic animals. Diseases at the wildlife-livestock interface, particularly those that are zoonotic, must be an area of focus for public health programs and surveillance for emerging infectious diseases. Additionally, understanding wildlife and their role is a vital part of understanding the epidemiology and ecology of diseases. To do this, a multi-faceted approach combining capacity building and training, wildlife disease surveillance, wildlife-livestock interface and disease ecology studies, data and information sharing and outbreak investigation are needed.  相似文献   

4.
There is increasing evidence that activation of innate immunity, in animals and man, by live vaccines, sub-unit vaccines or synthetic or non-synthetic stimulants can induce a profound and rapidly induced resistance to pathogens, including infectious agents that are unrelated to the stimulating antigen or agent. We review the evidence for this phenomenon and present the proposition that this approach might be used to stimulate immunity during the life of the animal when susceptibility to infection is high and when normal vaccination procedures may be inappropriate.  相似文献   

5.
The majority of interactions between microorganisms and animals are based on convenient relations for both of them. Symbiotic microorganisms, like intestinal microbiota, produce important vitamins for animals and protects them from putative pathogens. In general, for monogastric animals, the main contribution of intestinal microorganisms is to supply with growth factors the animal diet, and in some cases they are responsible for providing essential vitamins (e.g. vitamin K). Some particular and relatively few microbes like viruses, bacteria, fungi, protozoa and algae are responsible for animal illness. Because microorganisms are easily dispersed, display physiological diversity, and tolerate extreme conditions, they are ubiquitous and may contaminate and grow in many products, including food and raw materials. Foodborne diseases are caused by consumption of contaminated food or beverages. Many different disease-causing pathogens can contaminate food, so there are many different foodborne infections. In addition, poisonous chemicals and biological toxins can cause disease if they are present in food. To know how a particular disease is spreading is an important matter to take appropriate steps to stop it. For example Escherichia coli O157:H7 infections can spread through contaminated food (meat, vegetables, cheese, etc.), contaminated drinking water or juices, contaminated swimming water and from person to person. Among foodborne pathogens, the most frequently detected are bacteria, but also parasitic protozoa and worms, viruses, natural toxins and other pathogenic agents like prions are important agents for foodborne diseases. Particular pathogenic types of E. coli, classified by their specific pathogenic mechanisms (toxins, adhesins, invasiveness, etc.) are actually known as E. coli virotypes. Enterohaemorrhagic E. coli (EHEC), which constitute the main part of this review, were also named verotoxigenic E. coli (VTEC) or Shiga toxigenic E. coli (STEC). EHEC strains cause haemorrhagic colitis (HC), haemolytic uremic syndrome (HUS) and thrombotic thrombocytopaenic purpura (TP) in humans. They synthetize shigatoxins (verotoxins) which are potent cytotoxic substances, adherence factors and enterohaemolysin. EHEC are responsible for many outbreaks of bloody diarrhoea caused by contaminated foods: beef, milk, fruits, juice, water, etc. The most important serogroups among EHEC are O26, O111 and O157, being O157:H7 the most relevant serotype in foodborne outbreaks. The normal intestinal microflora of cattle was found to be the most relevant reservoir of EHEC strains.  相似文献   

6.
Many investigators focused on bats (Chiroptera) for their specific character, i.e. echolocation system, phylogenic tree, food practice and unique reproduction. However, most of basic information about the vital functions related to anti-viral activity has been unclear. For evaluating some animals as a natural reservoir or host of infectious pathogens, it is necessary that not only their immune system but also their biology, the environment of their living, food habits and physiological features should be clarified and they should be analyzed from these multi-view points. The majority of current studies on infectious diseases have been conducted for the elucidation of viral virulence using experimental animals or viral gene function in vitro, but in a few case, researchers focused on wild animal itself. In this paper, we described basic information about bats as follows; genetic background, character of the immunological factors, histological character of immune organs, the physiological function and sensitivity of bat cells to viral infection.  相似文献   

7.
荧光定量PCR技术及其在动物传染病定量检测中的应用   总被引:11,自引:0,他引:11  
荧光定量PCR是近年发展起来的一 种新的实时定量检测特定核酸技术,它是核 酸探针技术、荧光共振能量传递技术和PCR 技术的有机结合,而荧光探针是荧光定量 PCR的核心。目前报道的荧光探针主要有 TaqMan、Amplisensor、分子信标、Lightcycler 以及在这4种探针基础上发展起来的其他荧 光探针。各种荧光探针在定量PCR中的作 用是识别和报告特定核酸。这些荧光探针与 相应的靶分子杂交时经历一个自发荧光形成 或消失的构象变化,只有与完全互补的靶核 酸杂交时才会出现这种变化,当靶核酸存在 碱基错配或缺失时,荧光探针就不会与之杂 交,也不会出现荧光的变化。在检测时根据 这种荧光变化来确定检测中特定核酸的存在 和量的多少。荧光探针用于定量PCR不但 提高了PCR的检测灵敏度,还能在同一封闭 管中对模板进行准确定量检测,特别适合特 定核酸扩增的实时监测。荧光定量PCR用 于动物传染病的诊断,不但能定量检测病原 体感染的强弱和在机体内的分布,还具有灵 敏、快速、省力的特点。  相似文献   

8.
The pathogenesis of infectious agents with human tropism can only be properly studied in an in vivo model featuring human cells or tissue. Humanized mice represent a small animal model featuring human cells or tissue that can be infected by human-specific viruses, bacteria, and parasites and also providing a functional human immune system. This makes the analysis of a human immune response to infection possible and allows for preclinical testing of new vaccines and therapeutic agents. Results of various studies using humanized mice to investigate pathogens with human tropism are presented in this review. In addition, the limitations of humanized mice and methods to improve this valuable animal model are discussed.  相似文献   

9.
Because nosocomial and zoonotic diseases are inherent and ever-present risks in veterinary hospitals, proactive policies should be in place to reduce the risk of sporadic cases and outbreaks. Policies should ideally be put in place before disease issues arise, and policies should be effectively conveyed to all relevant personnel. Written policies are required for practical and liability reasons and should be reviewed regularly. Although no infection control program can eliminate disease concerns, proper implementation of barrier precautions and isolation can reduce the exposure of hospitalized animals and hospital personnel to infectious agents. Appropriate personal hygiene, particularly hand hygiene, can assist in the prevention of disease transmission when pathogens bypass barriers and are able to contact personnel. Veterinary hospitals have moral, professional, and legal requirements to provide a safe workplace and to reduce the risks to hospitalized patients. Based on experience in the human medical field and on the continual emergence of new infectious diseases, infection control challenges can only be expected to increase in the future. Regular reassessment of protocols based on ongoing research and clinical experiences is required.  相似文献   

10.
Infectious diseases are an important cause of morbidity and mortality in horses, along with economic costs and broader impacts associated with the loss of members of a species that generates income, acts as a working animal and is a companion. Endemic diseases continue to challenge, emerging diseases are an ever‐present threat and outbreaks can be both destructive and disruptive. While infectious diseases can never be completely prevented, measures can be introduced to restrict the entry of pathogens into a population or limit the implications of the presence of a pathogen. Objective research regarding infection control and biosecurity in horses is limited, yet a variety of practical infection prevention and control measures can be used. Unfortunately, infection control can be challenging, because of the nature of the equine industry (e.g. frequent horse movement) and endemic pathogens, but also because of lack of understanding or motivation to try to improve practices. Recognition of the basic concepts of infection control and biosecurity, and indeed the need for measures to control infectious diseases, is the foundation for successful infection prevention and control.  相似文献   

11.
Infectious factorial diseases of domesticated small animals are infection dependent diseases, whose pathogenesis is finally activated by additional, secondary factors, that influence the multiplying and spreading of latent and clinical symptomless infective agents present in the animals. These factorial diseases are not autonomous infectious processes, but only special types and courses of diseases by secondary activated infective agents. Secondary factors may be of exogenous origin (housing, climate, feeding, managing) or may arise by endogenic processes (immunity, resistance disregulations a.o.). In fur bearing animals and rabbits infectious factorial diseases arise by activation of latent, symptomless infections of mucosal membranes in the nose and oral cavity, in the intestinal tract, in the descending urinary tract and on the external skin. The majority of infection activating secondary factors go back on wrong housing conditions, extreme climate, malnutrition and simultaneous infections, but also animal specific situations and immunosuppression may influence the activation of latent infections. - Typical factorial diseases in fur bearing animals and rabbits are: the infectious coryza (Pasteurella multocida, Bordetella bronchiseptica) in rabbits, the Coli-dysentery and the enterotoxemia in rabbits and herbivorous fur animals, the ascending infections of urinary tract, particular in young male minks, and the different types of microbial dermatitis in all small animals. - In the prevention and control of infectious factorial diseases the improvement of housing and living conditions as well as feeding the animals with species conforming and nonobjectionable food are most important and essential measures.  相似文献   

12.
Reptiles can harbor pathogenic microorganisms asymptomatically and serve as potential reservoirs of infection for humans, domestic animals, and other reptiles. Infectious diseases are also problematic for free-ranging reptile populations and are an important consideration in reptile reintroduction and translocation projects. There have been limited serologic studies of free-ranging reptiles for evidence of exposure to potential pathogens. In the present study, serum or plasma samples from five male and five female free-ranging Venezuelan anacondas (Eunectes murinus) were screened for antibodies to eastern, western, and Venezuelan equine encephalitis viruses, vesicular stomatitis virus, ophidian paramyxovirus, 19 Leptospira interrogans serovars, and Cryptosporidium serpentes. Antibodies to these agents were not detected, or antibody titers were low and possibly nonspecific. These results for the limited number of anacondas surveyed suggest that they do not serve as significant reservoirs for these infectious agents at this location.  相似文献   

13.
Mastitis (intramammary inflammation) caused by infectious pathogens is still considered a devastating condition of dairy animals affecting animal welfare as well as economically incurring huge losses to the dairy industry by means of decreased production performance and increased culling rates. Bovine mastitis is the inflammation of the mammary glands/udder of bovines, caused by bacterial pathogens, in most cases. Routine diagnosis is based on clinical and subclinical forms of the disease. This underlines the significance of early and rapid identification/detection of etiological agents at the farm level, for which several diagnostic techniques have been developed. Therapeutic regimens such as antibiotics, immunotherapy, bacteriocins, bacteriophages, antimicrobial peptides, probiotics, stem cell therapy, native secretory factors, nutritional, dry cow and lactation therapy, genetic selection, herbs, and nanoparticle technology-based therapy have been evaluated for their efficacy in the treatment of mastitis. Even though several strategies have been developed over the years for the purpose of managing both clinical and subclinical forms of mastitis, all of them lacked the efficacy to eliminate the associated etiological agent when used as a monotherapy. Further, research has to be directed towards the development of new therapeutic agents/techniques that can both replace conventional techniques and also solve the problem of emerging antibiotic resistance. The objective of the present review is to describe the etiological agents, pathogenesis, and diagnosis in brief along with an extensive discussion on the advances in the treatment and management of mastitis, which would help safeguard the health of dairy animals.  相似文献   

14.
In summer of 2002, a case of severe clinical bovine anaplasmosis caused great losses in a dairy farm of an animal trader in Grisons. This article outlines the general approach of an outbreak investigation considering the case of anaplasmosis as an example. The goals of such investigations are to identify and eliminate the source of a disease outbreak in order to avoid additional cases. In addition, recommendations should be developed for preventing or limiting the magnitude of similar outbreaks in the future. In the outbreak presented, the causative agents were probably brought into the dairy farm by animal trade. Due to the large herd size, a missing quarantine for new animals and the coinfection with several pathogens, this case led to a high number of fatalities. The investigations of this outbreak demonstrated the importance of an universal and consistent identification of individual animals for the reconstruction of their movements. The veterinary practitioner should be reminded to act cautiously when facing strange clinical cases and to also consider "exotic diseases" as a possible cause.  相似文献   

15.
Microorganisms by far are representing the most important cause for food safety risks. Sources of food contamination are given along the whole food chain. The most frequent causative agents of food infections, Salmonella and Campylobacter, mostly can be found in the animals herds. A real improvement of the situation can only be reached by a strong inclusion of the agricultural area in the programs for repressing the pathogens. Problems in animal health and premortal stress of the slaughter animals cause considerable bacterial translocation processes and increase the consumer risks. Only few publications exist on the influence of the animal farming systems on the development of microbial food risks. The consumer accepts only animal management systems, which meet the demands for animal welfare, economical efficiency and especially the demand for product safety.  相似文献   

16.
储蓄  张军霞  王晶 《畜牧兽医学报》2021,52(12):3346-3356
动物机体内存在氧化还原平衡,正常状态下保持相对的稳态,当环境或自身状态发生改变时,这种平衡可能会被打破,进而引发机体氧化应激。研究发现,引起氧化应激的因素有很多:如环境因素、动物自身状态改变和外源致病菌以及病毒等,这些因素造成的氧化应激对动物的健康状况、生产性能和繁殖功能等方面会产生不同程度的影响,严重时甚至引发动物死亡,因此,寻求和添加安全有效的抗氧化制剂以调节动物氧化还原状态具有重要的现实意义。目前,针对动物氧化应激的营养性添加剂主要有益生菌、维生素、微量元素、激素类和植物类活性物质等。本文对引发动物氧化应激的主要原因和其对动物产生的影响进行了总结,并概括了具有缓解动物氧化应激功能的营养性饲料添加剂,以期为动物氧化应激和其缓解策略的进一步研究提供参考。  相似文献   

17.
Abortion in dairy cattle causes considerable economic losses to the dairy industry. Aborted fetuses and samples from the corresponding aborting dams from 12 dairy herds in Beijing were tested for 9 abortifacient infectious pathogens by PCR between 2008 and 2010. From a total of 80 abortion cases collected during this period, infectious agents were detected in 45 (56.3%) cases, 22 (48.9%) of which represented co-infections with two or three infectious agents. The detected pathogens included infectious bovine rhinotracheitis virus (36.3%) and Neospora caninum (31.3%), followed by bovine viral diarrhoea virus (7.5%), Brucella abortus (6.3%), Tritrichomonas foetus (5%) and Toxoplasma gondii (1.3%). Campylobacter fetus, Coxiella burnetii and Chlamydophila psittaci were not detected in any abortion case. Findings from this study indicated that infectious bovine rhinotracheitis virus and Neospora caninum were the main potential causes of abortions in Beijing dairy herds, whereas the bacterial pathogens were not, in contrast to reports from other countries. This is the first study to test nine abortifacient infectious agents by PCR at the same time, and it is also the first time to report the involvement of a variety of infectious agents in bovine abortion cases in China.  相似文献   

18.
Zoonotic diseases are infectious diseases transmittable between animals and humans and outbreaks of these diseases in animals can signify that humans are also infected (or vice versa). Thus, communication between animal and human health agencies is critical for surveillance. Understanding how these agencies conduct surveillance and share information is important for the development of successful automated zoonotic monitoring systems. Individual interviews were conducted with 13 professionals who perform animal or human zoonotic disease surveillance in one of the New England states. Questions centred on existing surveillance methods, collaborations between animal and human health agencies, and technological and data needs. The results showed that agencies routinely communicate over suspected zoonotic disease cases, yet there are barriers preventing automated electronic linking of health data of animals and humans. These include technological barriers and barriers due to sensitivity and confidentiality of information. Addressing these will facilitate the development of electronic systems for integrating animal and human zoonotic disease surveillance data.  相似文献   

19.
The concept of new and emerging diseases has captured the public interest and has revitalized the public health infectious disease research community. This interest has also resulted in competition for funding and turf wars between animal health and public health scientists and public officials and, in some cases, has delayed and hindered progress toward effective prevention, control and biodefense. There is a dynamic list of outbreaks causing substantial morbidity and mortality in humans and often in the reservoir animal species. Some agents have the potential to grow into major epidemics. There are many determinants that influence the emergence of diseases of concern that require the use of current understanding of the nature of agent persistence and spread. Additional factors that are global must be added to plans for prevention and control. To this complex mix has been added the potential for accidental or malicious release of agents. The nature of emerging infectious agents and their impact is largely unpredictable. Models that strive to predict the dynamics of agents may be useful but can also blind us to increasing disease risks if it does not match a specific model. Field investigations of early events will be critical and should drive prevention and control actions. Many disease agents have developed strategies to overcome extremes of reservoir qualities like population size and density. Every infectious agent spreads easier when its hosts are closer together. Zoonoses must be dealt with at the interface of human and animal health by all available information. Lessons learned from the emergence of and response to agents like West Nile virus, H5N1 avian influenza, SARS and bovine spongiform encephalopathy, the cause of new-variant Creutzfeldt-Jakob disease in humans, must be used to create better plans for response and meet the challenge for public health and biodefense.  相似文献   

20.
This paper describes a method to provide improved probability estimates that exposure to a specific dose of an airborne infectious pathogen will result in animal infection. Individual animals were exposed to a specific dose of airborne pathogen. Following exposure, animals were individually housed and monitored for evidence of infection. The detection of specific antibodies and/or the pathogen in diagnostic specimens was evidence that the exposure dose resulted in infection. If replicated over a range of doses, the results can be used to derive a dose-response curve for a variety of animal species and infectious pathogens. This information is useful in estimating the likelihood of infection associated with exposure to airborne infectious microorganisms. Applications include predicting the risk of transmission associated with exposure to airborne pathogens, modeling the transmission of airborne pathogens, and determining requirements for effective exposure doses for vaccines delivered in aerosols.  相似文献   

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