Isolation of porcine monocyte population: a simple and efficient method

Monocytes are important mediators of inflammatory processes and are in the focus of immunological studies. While the preparation of human monocytes is widely established, little is published on the isolation of porcine monocytes for experimental studies. The aim of this study is to establish a cost efficient method of preparing and culturing porcine monocytes of considerable purity and reasonable yield. In our method, we combined and modified different protocols of human monocyte preparation. The blood of a single pig is harvested and treated with EDTA to prevent coagulation. Peripheral blood mononuclear cells are obtained by a density gradient centrifugation using a Bicoll gradient and monocytes are harvested by culturing on serum-treated culture flasks, rinsing and tapping. A high yield is obtained by constant cooling of flasks and tubes. The purity of the culture is evaluated by the expression of CD14, using flow cytometry. Using this method, we reached a purity of 92.6 % (+/? 3.06 %). With this procedure, we established a reliable method to prepare and cultivate porcine monocytes which can be performed cost effectively and does not require special equipment.     

Robust surveillance of animal diseases: an application to the detection of bluetongue disease

Control of endemic, exotic, and emerging animal diseases critically depends on their early detection and timely management. This paper proposes a novel approach to evaluate alternative surveillance programs based on info-gap theory. A general modeling framework is developed explicitly accounting for severe uncertainty about the incursion, detection, spread, and control of exotic and emergent diseases. The model is illustrated by an evaluation of bluetongue disease surveillance strategies. Key results indicate that, when available, vaccination of the entire population is the most robust strategy. If vaccines are not available then active reporting of suspect clinical signs by farmers is a very robust surveillance policy.     

Re-emergence of bluetongue, African horse sickness, and other Orbivirus diseases

Arthropod-transmitted viruses (Arboviruses) are important causes of disease in humans and animals, and it is proposed that climate change will increase the distribution and severity of arboviral diseases. Orbiviruses are the cause of important and apparently emerging arboviral diseases of livestock, including bluetongue virus (BTV), African horse sickness virus (AHSV), equine encephalosis virus (EEV), and epizootic hemorrhagic disease virus (EHDV) that are all transmitted by haematophagous Culicoides insects. Recent changes in the global distribution and nature of BTV infection have been especially dramatic, with spread of multiple serotypes of the virus throughout extensive portions of Europe and invasion of the south-eastern USA with previously exotic virus serotypes. Although climate change has been incriminated in the emergence of BTV infection of ungulates, the precise role of anthropogenic factors and the like is less certain. Similarly, although there have been somewhat less dramatic recent alterations in the distribution of EHDV, AHSV, and EEV, it is not yet clear what the future holds in terms of these diseases, nor of other potentially important but poorly characterized Orbiviruses such as Peruvian horse sickness virus.     

牛蓝舌病黏膜病和传染性鼻气管炎的血清学调查

牛蓝舌病、黏膜病和传染性鼻气管炎是分别由蓝舌病病毒、牛病毒性腹泻—黏膜病病毒和牛鼻气管炎病毒引起的 3种传染病。为了摸清这 3种疫病在楚雄州的存在、分布及流行情况 ,为制定防疫对策与措施提供科学依据 ,笔者在州内选择具有代表性的地区进行了牛蓝舌病、黏膜病和传染性鼻气管炎的血清学调查。1　材料与方法1 .1　受检血清　选择州内分别代表坝区、半山区、山区、亚热带地区的楚雄、姚安、双柏、元谋 4县 (市 )农户散养成年牛 62 7头 (水牛 32 0头 ,黄牛 30 7头 ) ,采集血样 ,分离血清 ,低温保存备检。调查统计时又从各县细分出坝区、…     

Equine infectious anemia virus: development of a simple reproducible method for titrating infectivity of the cell-adapted strain.

An equine dermal cell line between the 14th and 30th subpassages was used to develop a reproducible method of titrating the infectivity of the cell-adapted strain of equine infectious anemia virus (EIAV). Cells inoculated with EIAV were subcultured or fed once each week and were monitored for the production of P26 antigen of EIAV in supernatant fluids. Ultrathin sections were prepared once each week and were examined for the detection of budding virus-like particles (VLP). The VLP could not be detected in the infected cells subcultured once each week. When the medium was changed once week and when the cells not transferred, budding VLP were detected routinely after 3 to 4 weeks, Feeding of the infected cells once each week was used to establish the infectivity assay. The reproducibility of the assay on a frozen viral stock preparation was within an endpoint of one tenfold dilution.     

A simple and efficient method for extraction of PCR-amplifiable DNA from chicken eggshells

Recently, we reported a method for discriminating a Japanese brand of chicken, the Hinai-jidori. As an application of this method for discriminating Hinai-jidori eggs, we here report an efficient method for extracting maternal DNA from eggshells. Eggshell powder was completely decalcified with EDTA solution, and then DNA was isolated by conventional phenol-chloroform extraction and ethanol precipitation. The efficiency of DNA recovery from eggshells was 50-fold higher than that of a previously reported method. The recovered DNA could be used for PCR, and 10 markers for identifying the Hinai-jidori chicken were detected. The genotypes of the Hinai-jidori exactly matched those of the Hinai-dori breed. Using this method, Hinai-jidori and Hinai-dori eggs could be distinguished from the eggs of Rhode Island Reds. This is the first report of a technique that can be used to discriminate the eggs of Hinai-jidori from those of other chickens, and it can also be utilized to validate the labeling of Hinai-jidori eggs in the market.     

Slide precipitation: a simple method to type Actinobacillus (Haemophilus) pleuropneumoniae

Soluble thermostable antigens prepared from Actinobacillus pleuropneumoniae, as commonly applied in the ring precipitation test, were used in rapid slide tests. This method was easier to perform than the ring precipitation test and showed the same specificity. This specificity was higher than that obtained in slide agglutination tests using whole bacterial cells.     

西藏林芝地区鸡的主要传染病

通过对西藏林芝地区养鸡业流行病的调查 ,总结了近年来该地区鸡病发生的趋势。对危害严重的 9种疾病和病原进行了较深入的分析 ,并提出了相应的预防措施     

A simple and efficient method for isolation of a single Eimeria oocyst from poultry litter using a micromanipulator

The chicken, which is the host for seven species of Eimeria, typically is infected simultaneously by multiple Eimeria species and the oocysts of coccidia are excreted in the feces. A prerequisite for investigation of individual Eimeria species is to isolate a single oocyst from fecal samples. A novel method for isolating a single Eimeria oocyst from poultry litter using a micromanipulator was developed. This simple method is fast and reliable, and provides direct isolation of a single sporulated oocyst from fecal samples harboring multiple Eimeria species or samples contaminated by other species of parasite.     

An immunologist's perspective on nutrition,immunity, and infectious diseases: Introduction and overview

The immune system is a multifaceted arrangement of membranes (skin, epithelial, and mucus), cells, and molecules whose function is to eradicate invading pathogens or cancer cells from a host. Working together, the various components of the immune system perform a balancing act of being lethal enough to kill pathogens or cancer cells yet specific so as not to cause extensive damage to “self” tissues of the host. A functional immune system is a requirement of a healthy life in modern animal production. Yet infectious diseases still represent a serious drain on the economics (reduced production, cost of therapeutics, and vaccines) and welfare of animal agriculture. The interaction involving nutrition and immunity and how the host deals with infectious agents is a strategic determinant in animal health. Almost all nutrients in the diet play a fundamental role in sustaining an optimal immune response, such that deficient and excessive intakes can have negative consequences on immune status and susceptibility to a variety of pathogens. Dietary components can regulate physiological functions of the body; interacting with the immune response is one of the most important functions of nutrients. The pertinent question to be asked and answered in the current era of poultry production is whether the level of nutrients that maximizes production in commercial diets is sufficient to maintain competence of immune status and disease resistance. This question, and how to answer it, is the basis of this overview. Clearly, a better understanding of the interactions between the immune signaling pathways and productivity signaling could provide the basis for the formulation of diets that optimize disease resistance. By understanding the mechanisms of nutritional effects on the immune system, we can study the specific interactions that occur between diet and infections. This mechanism-based framework allows for experiments to be interpreted based on immune function during an infection. Thus, these experiments would provide a “real world” assessment of nutritional modulation of immune protection separating immune changes that have little impact on resistance from those that are truly important. Therefore, a coordinated account of the temporal changes in metabolism and associated gene expression and production of downstream immune molecules during an immune response and how nutrition changes these responses should be the focus of future studies. These studies could be answered using new “-eomics” technologies to describe both the local immune environments and the host-pathogen interface.     

Modeling of host genetics and resistance to infectious diseases: understanding and controlling nematode infections

This paper considers approaches to modeling the dynamics of infectious disease and the application of such models to nematode parasite infections in ruminants. Particularly, these models are developed to account for host genetics and may be used to assess the effects of using genetics to control nematode infections. Three main issues are critically examined: the infection transmission cycle from pasture to host to pasture, the expected genetic relationships between resistance and performance, and the risks of parasite evolution in response to genetic changes in the host. To obtain answers that are realistic and of practical use, the modeling approaches require a solid grounding in biology. This biology is formalized and described using mathematical techniques, with the models parameterized using experimental or field data. Transmission dynamics have been quantified by modeling and are backed by strong experimental data. Selection for resistance will be successful in reducing egg output, pasture larval contamination and hence subsequent larval challenge. Modeling frameworks have been developed to predict genetic relationships between resistance to infectious disease and performance in general, and genetic correlations predicted for nematode resistance are close to mean published values. These predicted correlations strengthen as the larval challenge increases and the dietary (protein) adequacy decreases, however modeling challenges remain. Lastly, although convincing experimental data is not yet available, arguments based on modeling suggest that the risks of parasite evolution in response to genetic changes in the host should be less than the risks arising from other control strategies, such as anthelmintics. Thus, modeling techniques predict that selective breeding for resistance should be an effective and sustainable complementary control measure.     

Real-time polymerase chain reaction: a novel molecular diagnostic tool for equine infectious diseases

The focus of rapid diagnosis of infectious disease of horses in the last decade has shifted from the conventional laboratory techniques of antigen detection, microscopy, and culture to molecular diagnosis of infectious agents. Equine practitioners must be able to interpret the use, limitations, and results of molecular diagnostic techniques, as they are increasingly integrated into routine microbiology laboratory protocols. Polymerase chain reaction (PCR) is the best-known and most successfully implemented diagnostic molecular technology to date. It can detect slow-growing, difficult-to-cultivate, or uncultivatable microorganisms and can be used in situations in which clinical microbiology diagnostic procedures are inadequate, time-consuming, difficult, expensive, or hazardous to laboratory staff. Inherent technical limitations of PCR are present, but they are reduced in laboratories that use standardized protocols, conduct rigid validation protocols, and adhere to appropriate quality-control procedures. Improvements in PCR, especially probe-based real-time PCR, have broadened its diagnostic capabilities in clinical infectious diseases to complement and even surpass traditional methods in some situations. Furthermore, real-time PCR is capable of quantitation, allowing discrimination of clinically relevant infections characterized by pathogen replication and high pathogen loads from chronic latent infections. Automation of all components of PCR is now possible, which will decrease the risk of generating false-positive results due to contamination. The novel real-time PCR strategy and clinical applications in equine infectious diseases will be the subject of this review.