野生动物隐孢子虫的种类和基因型

隐孢子虫病（Cryptosporidiosis）是一种全球性的人兽共患原虫病,具有广泛的宿主范围,可以感染鸟类、哺乳类、鱼类、爬行类、两栖类以及人在内的240多种动物。野生动物隐孢子虫做为人隐孢子虫病感染的重要传播来源,对其进行生物学研究具有重要的公共卫生意义。本文分别叙述了野生动物隐孢子虫的种类及基因型,为进一步研究野生动物的隐孢子虫病提供了有效的参考。     

隐孢子虫病的流行现状

隐孢子虫病是由隐孢子虫(Cryptosporidium)寄生于人类、家养动物及多种野生动物胃肠道引起的一种严重的人畜共患胃肠疾病。该病不但威胁人类健康,亦严重影响畜牧业发展。近年来随着研究的深入,隐孢子虫的流行表现出许多新的特点,危害远远超出了人们的估计。这些特点主要表现在：感染家畜,增加人类感染风险;与动物其他病原混合感染危害加重;感染野生动物,具有自然疫源性;感染海洋和水生动物,造成水体污染;经水源和食物传播引起人类群体感染;暴发感染对人群危害严重。深入开展隐孢子虫病流行病及防控研究对提高公共卫生水平具有重要意义。     

一种威胁养鸡业的新病——鸡隐孢子虫病

近几年来,一种鲜为人知的寄生虫——雏鸡隐孢子虫(Cryptosporidium)的检出率有所增加。Giambrone 认为,隐孢子虫的传播可以导致一种新型疾病,它将会给养鸡业带来重大的损失.隐孢子虫病(由隐孢子虫引起)过去一直被认为只侵害机体非重要器官,最近才发现隐孢子虫病能引起某些禽类的呼吸系统严重感染.Giambrone 指出,隐孢子虫是由呼吸道排出,但尚不能确定感染多少隐孢子虫才致发病.他和其他研究人员首次分离了单细胞虫体,并且发现能够单独地引起呼吸系统疾病,     

隐孢子虫病的防治

隐孢子虫病是由不同虫种的隐孢子虫引起的,在世界范围内能够广泛导致人和动物腹泻的疾病。学者们对隐孢子虫的流行情况、预防和治疗展开了广泛的调查研究,一些药物及疫苗等在体内外实验中具有积极的效果。本文就当前隐孢子虫病的流行状况、药物及技术在动物隐孢子虫病防控的应用现状作了介绍。     

动物隐孢子虫病

隐孢子虫病是多种动物共患的一种原虫病。病原体为孢子虫纲真球孢子虫目隐孢子虫属原虫,可侵袭犊牛、马驹、绵(山)羊羔、禽、兔等动物,也可感染人。此病主要症状是下痢,通过饮食和空气传播。美国于1971年首先报道家畜隐孢子虫病。     

隐孢子虫病检测技术研究进展

隐孢子虫是动物和人腹泻的重要病原,也是人类艾滋病患者的主要致死因素之一.当前,对隐孢子虫病的研究已成为全球寄生虫学研究领域的热点由,于迄今尚无治疗隐孢子虫病感染的特效药物,因此,快速、简便、准确地发现隐孢子虫是控制该病的关键.随着分子生物学技术的应用,隐孢子虫病的检测技术得到了极大的发展.笔者就近年来隐孢子虫病检测技术进行了简要综述.     

广西2月龄内犊奶牛隐孢子虫感染情况调查

<正>自Tyzzer(1907)首次发现小鼠隐孢子虫(C.muris)以来,国内外学者对隐孢子虫病进行了大量研究,已在人、哺乳动物、禽类、爬行动物和鱼类等多种动物中发现15个种类的隐孢子虫感染[1-3],其中可感染牛的隐孢子虫种为安氏隐孢子虫(C.an-dersoni)、小球隐孢子虫(C.parvum)、牛隐孢子虫(C.bovis)、小鼠隐孢子虫(C.muris)、犬隐孢子虫(C.ca-     

猪隐孢子虫和隐孢子虫病的研究进展

隐孢子虫病是一种全球性的人兽共患病 ,猪隐孢子虫病世界各地均有报道 ,严重威胁着人类和动物的健康。本文对猪隐孢子虫病的病原分类、虫体形态和生活史、流行病学特点、诊断、防治等方面目前研究状况进行了综述 ,为猪隐孢子虫病的有效防制提供参考     

我国牛隐孢子虫感染情况及危险因素研究进展

动物感染隐孢子虫会出现腹泻、厌食等症状,甚至出现死亡,尤其对免疫系统尚未发育完全的幼畜威胁更大。隐孢子虫病的危害往往被低估和忽视,被感染的动物产品对人类的健康存在潜在威胁。不同地区牛的隐孢子虫感染情况和影响因素存在差异。基于此,本文就隐孢子虫在我国的感染情况及其危险因素进行综述,为其防控提供参考。     

雏鸡隐孢子虫感染对新城疫免疫的影响

隐孢子虫寄生于多种动物,常引起宿主腹泻和呼吸困难等临床症状。目前,国内外已有不少关于本病的报道,但罕见隐孢子虫对宿主免疫影响的研究。为探索隐孢子虫感染与雏鸡新城疫疫苗免疫效果的关系,我们对感染隐孢子虫的病雏进行新城疫疫苗接种后,再作新城疫人工发病试验。结果,隐孢     

Illustration of the maternal animal model used for genetic evaluation of beef cattle

National cattle evaluation programs for weaning weight in most beef breed associations involve implementation of the maternal animal model to predict direct and maternal EPD. With this model, direct breeding values are predicted for all animals with records or pedigree ties to animals with records, or both. Even though maternal genetic value is expressed only in animals that become dams, these effects are transmitted by all parents and inherited from parents by all animals, leading to maternal breeding values being predicted for all animals as well. A small example data set was simulated involving 12 parents, 8 nonparents, and 13 animals with weaning weight records. The pedigree was developed to include paternal and maternal half-sib families, full-sibs, and some inbreeding, similar to field populations of beef cattle. Assembly of the mixed model equations and solutions for the maternal animal model are illustrated explicitly to assist animal breeding students in their understanding of the properties of the maternal animal model and to explicitly implement the model. Model parameters and moments, fixed contemporary group solutions, adjustment of breeding values for merit of mates, interpretation of maternal permanent environmental effect solutions, and alternatives for the assembly of the equations are shown. This example should lead to increased student and producer understanding of genetic improvement programs for weaning weight in beef cattle.     

Animal model for genetic evaluation of multibreed data.

Extension of beef cattle genetic evaluation procedures to multibreed data sets is proposed as a way to allow inclusion of crossbred animals into current analyses and to provide comparisons between purebred animals of different breeds. Previous papers dealing with multibreed BLUP have proposed sire or sire-maternal grandsire models. Because current models used in the beef industry are predominantly of the reduced animal model form, models were developed for animal model and reduced animal model mixed-model evaluations that would account for fixed and random additive genetic effects, along with fixed and random nonadditive genetic effects for populations with heterogeneous means and variances.     

Modeling the relationship between food animal health and human foodborne illness

To achieve further reductions in foodborne illness levels in humans, effective pre-harvest interventions are needed. The health status of food animals that are destined to enter the human food supply chain may be an important, although often overlooked, factor in predicting the risk of human foodborne infections. The health status of food animals can potentially influence foodborne pathogen levels in three ways. First, diseased animals may shed higher levels of foodborne pathogens. Second, animals that require further handling in the processing plant to remove affected parts may lead to increased microbial contamination and cross-contamination. Finally, certain animal illnesses may lead to a higher probability of mistakes in the processing plant, such as gastrointestinal ruptures, which would lead to increased microbial contamination and cross-contamination. Consequently, interventions that reduce the incidence of food animal illnesses might also help reduce bacterial contamination on meat, thereby reducing human illness. Some of these interventions, however, might also present a risk to human health. For example, the use of antibiotics in food animals can reduce rates of animal illness but can also select for antibiotic-resistant bacteria which can threaten human treatment options. In this study, we present a mathematical model to evaluate human health risks from foodborne pathogens associated with changes in animal illness. The model is designed so that potential human health risks and benefits from interventions such as the continued use of antibiotics in animal agriculture can be evaluated simultaneously. We applied the model to a hypothetical example of Campylobacter from chicken. In general, the model suggests that very minor perturbations in microbial loads on meat products could have relatively large impacts on human health, and consequently, small improvements in food animal health might result in significant reductions in human illness.     

Laboratory animal science: a resource to improve the quality of science

The contribution of animal experimentation to biomedical research is of undoubted value, nevertheless the real usefulness of animal models is still being hotly debated. Laboratory Animal Science is a multidisciplinary approach to humane animal experimentation that allows the choice of the correct animal model and the collection of unbiased data. Refinement, Reduction and Replacement, the "3Rs rule", are now widely accepted and have a major influence on animal experimentation procedures. Refinement, namely any decrease in the incidence or severity of inhumane procedures applied to animals, has been today extended to the entire lives of the experimental animals. Reduction of the number of animals used to obtain statistically significant data may be achieved by improving experimental design and statistical analysis of data. Replacement refers to the development of validated alternative methods. A Laboratory Animal Science training program in biomedical degrees can promote the 3Rs and improve the welfare of laboratory animals as well as the quality of science with ethical, scientific and economic advantages complying with the European requirement that "persons who carry out, take part in, or supervise procedures on animals, or take care of animals used in procedures, shall have had appropriate education and training".     

Ethical issues in the ownership of companion animals: An empirical and normative analysis

Summary

This article deals with the ethical aspects of companion animal ownership. Research was done by means of interviews (n=40) and questionnaires (n=871). Respondents were randomly chosen from Dutch telephone directories. Euthanasia, docking tails, ear clipping and sterilisation are discussed on the basis of the opinions of respondents.

Owners of companion animals very often seem to have insufficient knowledge about animal behaviour. Companion animal owners as a group differ rather strongly in their moral opinions about the acceptability of certain actions towards animals. At the individual level also people are not always consequent in their reasoning as was illustrated by their opinions about ear clipping and the stopping of tail docking and vice versa. Respondents live in a community with animals and usually use a utilitarian balancing model. The different outcomes of the uses of this balancing model indicate how far the respondents are willing to adapt their life style to the needs of an animal; in other words to what extent intrinsic values and integrity are taken into account within the process of (re)creating a living community.     

Ethical issues in the ownership of companion animals: an empirical and normative analysis.

This article deals with the ethical aspects of companion animal ownership. Research was done by means of interviews (n = 40) and questionnaires (n = 871). Respondents were randomly chosen from Dutch telephone directories. Euthanasia, docking tails, ear clipping and sterilisation are discussed on the basis of the opinions of respondents. Owners of companion animals very often seem to have insufficient knowledge about animal behaviour. Companion animal owners as a group differ rather strongly in their moral opinions about the acceptability of certain actions towards animals. At the individual level also people are not always consequent in their reasoning as was illustrated by their opinions about ear clipping and the stopping of tail docking and vice versa. Respondents live in a community with animals and usually use a utilitarian balancing model. The different outcomes of the uses of this balancing model indicate how far the respondents are willing to adapt their life style to the needs of an animal; in other words to what extent intrinsic values and integrity are taken into account within the process of (re)creating a living community.     

Necessary changes to improve animal models

Animal models evolved from sire models and inherited some issues that affected sire models. Those issues include definition and treatment of contemporary groups, accounting for time trends and dealing with animals having unknown parents. The assumptions and limitations of the animal model need to be kept in mind. This review of the animal model will discuss the issues and will recommend enhancements to animal models for future applications.     

Surgical education: attitudes toward animal use in teaching surgery at Louisiana State University

Concerns over the use of animals in teaching have lead to a reduction in the number of live animal laboratories. A survey of 275 students and faculty was conducted to characterize their attitude toward the use of animals in teaching surgery. Respondents favored live animal use. They believed that model laboratories were helpful in learning aseptic technique and suturing skills but less helpful in learning tissue handling, dissection, hemostasis, or anesthesia.     

Reducing the effect of parent averages from animal solutions in mixed model equations

Selection of animals based on their BLUP evaluations from an animal model results in animals that are closely related which leads to increased rates of inbreeding. The tendency for higher inbreeding rates is greater at low heritability values. Several attempts have been made to reduce the impact of parent average breeding values from animals evaluations in order to reduce inbreeding while not sacrificing genetic response. A method that modifies the rules for forming the inverse of the additive genetic relationship matrix for use in best linear unbiased estimation of breeding values via an animal model was developed. This method and several others were compared analytically and empirically, from the perspective of partitioning the animal solutions into contributions from the data, from progeny, and from the parent average. The ratio of genetic progress to average level of inbreeding showed that the modified relationship matrix method was superior to the other methods. Similar results could be obtained by using artificially high heritability in a usual BLUP analysis.     

Investigation of the Role of Companion Animals in the Zoonotic Transmission of Cryptosporidiosis

Companion animals owned by human patients with cryptosporidiosis (cases) and those animals owned by the wider human population (controls), were studied to determine whether Cryptosporidium was more likely to be excreted by case animals than controls. A total of 280 recently voided faecal samples (114 case animals and 166 control animals) were collected and tested by immunomagnetic separation and immunofluorescent microscopy. A multivariable model was also created to identify pet characteristics, contacts and management factors associated with Cryptosporidium infection in animals, using information collected by a standardized questionnaire. The model was designed to take into account the clustering of samples at the owner level and whether the sampled animal was a case or control.