羊副结核病的诊断与防控

羊副结核病作为一种慢性接触性传染病,由副结核分枝杆菌引起,以病羊顽固性腹泻、渐进性消瘦为主要特征,对养羊业危害巨大。本文总结了羊副结核病的病原学、流行病学、临床症状、病理变化和诊断,并提出了综合生物安全措施,以期为养羊场(户)防控本病提供技术参考。     

羊副结核病的综合防控措施

羊副结核病又称羊副结核性肠炎,是一种由副结核分枝杆菌引起的羊的慢性传染病。该病的主要特征是肠壁增厚,形成皱褶,顽固性腹泻,逐渐消瘦。在我国呈散发或地方性流行,对养殖业危害较大。笔者结合生产实践经验,简要介绍了该病的病原、流行特点、临床症状、剖检病变和鉴别诊断,最后提出了综合防控措施,以期为该病的诊治提供有益参考。     

一起羊副结核病的诊断报告

介绍了一起羊副结核病的流行病学调查、临床症状、病理变化、实验室检查及鉴别诊断,并提出相应的防控措施,以供兽医人员和养殖户参考。     

牛副结核病的流行病学特征与实验室诊断技术研究进展

牛副结核病(bovine paratuberculosis)是由副结核分支杆菌引起的以牛慢性增生性、顽固性肠炎和进行性消瘦为特征的人畜共患传染病。其临床症状与病理变化是顽固性腹泻、渐进性消瘦、慢性肉芽肿回肠炎,肠粘膜增厚并形成皱褶。除常规的临床诊断外,牛副结核病的确诊依赖于实验室诊断方法,主要有病原学诊断、血清学诊断和分子生物学诊断等方法。牛副结核病给畜牧业造成很大的损失。由于本病潜伏期长,传播快,加之人工培养副结核分枝杆菌难度又高,因此加强对该病的病原学、流行病学特征的认识,加快实验室诊断方法的研究对其综合防控工作具有十分重要的意义。作者主要介绍了目前国内外牛副结核病流行病学特征和诊断方法的研究进展,并比较了各种方法的优点和缺点,为牛副结核病的临床快速诊断和深入研究提供科学依据。     

牛副结核病的危害及其防控措施

由副结核分枝杆菌引起牛的副结核病常导致感染牛的慢性增生性肠炎,以及体重、产奶量等生产性能下降,给畜牧业带来了严重的经济损失,目前尚无有效治疗药物。人们常采用不同的检测技术定期对牛群进行监测、淘汰活动带菌期的牛、对牛群进行疫苗接种、采用生物安全防控等措施比较有效地避免了副结核分枝杆菌在牛群中的传播。文章主要从副结核分枝杆菌背景,牛副结核病的危害及防控措施三个方面进行了综述,以期为牛副结核病的防控提供思路。     

澳大利亚进境种羊副结核感染情况调查

[目的]为摸清澳大利亚进境种羊副结核病的感染情况。[方法]采用皮内变态反应试验(TST)和酶联免疫吸附试验(ELISA)对6810头种羊进行调查。[结果]104头羊副结核病检测呈阳性,阳性率为1.53%。[结论]澳大利亚进境种羊副结核病的感染率虽然不高,但此病严重威胁着羊业的发展,应该高度重视该病的防控。     

用琼脂扩散反应方法诊断羊副结核病

国外很早就有人推荐用琼脂扩散反应方法诊断羊副结核病。我国至今还没有应用该种方法诊断羊副结核病。内蒙某羊场自1983年以来,不断有软便、消瘦而死亡的病羊发生,给畜主造成很大的经济损失。后经吉林省兽研所用细菌学和病理组织学方法确诊为羊副结核病。我们于1987年采用牛副结核胞浆抗原,用琼脂扩散方法对该场23群,3516只羊进行了检查。结     

副结核病诊断技术研究进展

副结核病(Paratuberculosis)呈世界性流行,该病对畜牧业的危害严重,仅在美国造成经济损失就高达200亿美元[1],我国将其列入二类多种动物共患传染病.由于该病具有潜伏期长、部分患病动物临床症状不明显等特点,使该病的防控更为困难,因而针对该病建立快速有效地检测方法显得尤为重要.近年来,虽然人们对副结核分枝杆菌病的研究取得了很大进展,但由于该病潜伏期长以及对培养基需求苛刻,使得总体上在该领域的研究进展缓慢.本文就目前国内外有关副结核病诊断方法的研究进展情况进行综述,希望为进出境检验检疫相关部门提供快速、准确地诊断副结核病提供参考.     

牛副结核病诊断技术的研究进展

牛副结核病是由副结核分枝杆菌引起的以牛慢性增生、顽固性肠炎、进行性消瘦及产奶量下降为特征的人畜共患传染病,可给畜牧业造成巨大的经济损失,目前还没有有效的治疗方案。早期快速、准确的诊断,对于预防和消除副结核病、保护人们的身体健康和促进我国畜牧业的健康高效发展具有十分重要的意义。随着研究的深入,针对副结核分枝杆菌的诊断技术不断被开发。本文从病原学、免疫学、分子生物学角度对牛副结核分枝杆菌的诊断技术进行了介绍,以期能够为牛副结核病的快速诊断和深入研究提供参考。     

用脂阿拉伯甘露聚糖抗原的酶免疫试验诊断绵羊副结核病

反刍动物副结核病尚缺乏一个较灵敏而特异的血清学诊断方法。用粗制多糖抗原作牛羊血清的补体结合试验(CFT)已有若干年。自1981年以来,也有用超声裂解物或培养过滤物制备抗原进行琼脂凝胶免疫扩散试验(AGID)诊断羊副结核病。近来发展     

绵羊种布鲁菌致病机制与防控研究进展

布鲁菌病(Brucellosis)是一种高度流行的人畜共患传染病,可造成巨大的经济损失,严重制约了当今畜牧业的发展并对人类健康构成了严重威胁。绵羊种布鲁菌病是由绵羊种布鲁菌(Brucella ovis,B.ovis)引起的一种以绵羊生殖系统功能障碍和怀孕绵羊流产为特征的慢性传染性疾病。目前,对于绵羊种布鲁菌的胞内寄生机制和感染机制尚不清楚,现将从病原学、流行病学、致病机制和疾病防控等方面对绵羊种布鲁菌病的研究进展进行概述,为后期挖掘绵羊种布鲁菌的致病机理和与其相关的研究奠定一定的理论基础。     

Temporal patterns and quantification of excretion of Mycobacterium avium subsp paratuberculosis in sheep with Johne's disease

OBJECTIVES: To determine the frequency of excretion of Mycobacterium avium subsp paratuberculosis in Merino sheep with Johne's disease and to quantify excretion in a group of Merino sheep. DESIGN: A pen and laboratory experiment. PROCEDURE: Seven sheep selected from an affected flock on the basis of acid-fast bacilli in the sheep's faeces were housed and total daily faecal output was collected, weighed and subjected to culture for M avium subsp paratuberculosis. An end-point titration method was used to enumerate viable M avium subsp paratuberculosis in a 15 day pooled sample from five sheep that had acid-fast bacilli in their faeces while housed. RESULTS: Four sheep with subclinical multibacillary Johne's disease excreted M avium subsp paratuberculosis each day for 11 days of cultural observation. A further three sheep were intermittent excreters but lacked other evidence of infection with M avium subsp paratuberculosis. The average number of viable bacteria excreted was 1.09 x 10(8) per gram of faeces while total daily excretion was 8.36 x 10(10) viable M avium subsp paratuberculosis per sheep. Examination of faecal smears stained with Ziehl Neelsen was an unreliable means of assessing daily excretion in individual animals except in those with severe lesions. CONCLUSION: Excretion of M avium subsp paratuberculosis in Merino sheep with multibacillary Johne's disease occurred daily, proving that environmental contamination can be continuous on farms with endemic ovine Johne's disease. Faecal culture is a useful method for detecting infection as it does not appear to be affected by the timing of collection of a sample from sheep with multibacillary disease however, to maximise the sensitivity of disease surveillance using faecal culture, sampling rates should be adjusted to take account of the proportions of multibacillary and paucibacillary cases.     

Sensitivity and specificity of two serological tests for the detection of ovine paratuberculosis

OBJECTIVE: To determine the sensitivity and specificity of an absorbed ELISA and an AGID test for the detection of clinical and subclinical paratuberculosis in sheep. DESIGN: By testing a panel of sera from 1257 Australian Merino and crossbred sheep greater than 1 year of age, of which 1137 sheep were not infected with Mycobacterium avium subsp paratuberculosis and 120 sheep had paratuberculosis. PROCEDURE: Sera were collected from 457 sheep in Victoria and 800 sheep in Western Australia. Presence of M a paratuberculosis infection in Victorian sheep was determined by histological examination of intestinal tissues, whereas sheep from Western Australia were presumed to be free of Johne's disease. The ability of an absorbed ELISA to discriminate between infected and uninfected sheep was described by test sensitivity and specificity, the distribution of ELISA OD, and the area under a receiver operating characteristic curve. RESULTS: The absorbed ELISA had a specificity of 98.2 to 99.5% (CI) and a sensitivity of 35 to 54% (CI). In sheep from infected flocks in Victoria, the AGID test had a specificity of 99 to 100% (CI) and a sensitivity of 38 to 56% (CI). The sensitivity of serological tests was higher in sheep with a body condition representative of the lower quintile of their flock of origin. CONCLUSION: The AGID test and absorbed ELISA are useful tests for the detection of ovine paratuberculosis. Although the tests had a similar accuracy, they detected different subpopulations of infected sheep with only moderate overlap. The AGID test had a higher specificity than the absorbed ELISA.     

贵州山区小反刍兽疫综合防控措施

小反刍兽疫又被称为羊瘟或伪牛瘟,是小反刍兽疫病毒引起的山羊及绵羊的一种急性接触性传染病,以发热、口炎、腹泻、肺炎为特征,该病发病率和病死率均较高,严重阻碍畜牧业高质量发展,研究该病的诊断及防控有着十分重要的意义。本文从该病的流行病学、临床症状、病理变化、实验室诊断方法以及综合防控措施等方面进行阐述,为广大养殖户提供参考。     

Use of the polymerase chain reaction assay for the detection of Mycobacterium avium subspecies paratuberculosis in blood and liver biopsies from experimentally infected sheep

OBJECTIVE: To evaluate a polymerase chain reaction-based assay for the detection of Mycobacterium avium subsp paratuberculosis in blood and liver biopsies from subclinically infected sheep. STUDY DESIGN: A direct PCR assay for the detection of M a paratuberculosis was applied to liver biopsy specimens and to samples of blood that were sequentially collected over 53 weeks from 14 sheep infected experimentally with the organism. RESULTS: Of 117 blood samples from the 14 experimentally infected sheep, two tested positive in the PCR assay. Both positive results were obtained in two subclinically infected sheep that had paratuberculosis later confirmed by histological examination at necropsy. However, the assay failed to detect the target DNA in samples of blood from five other sheep with histologically confirmed paratuberculosis. Similarly, the PCR assay on liver biopsy specimens collected 32 weeks after administration of M a paratuberculosis gave only two positive results, both of which were obtained in sheep with histological evidence of paratuberculosis. CONCLUSIONS: The PCR assay on blood and liver biopsies does not provide a useful method for the diagnosis of M a paratuberculosis infection in subclinically infected sheep.     

种畜禽场疫病防控与净化现状分析

伴随着我国畜牧业的快速发展,疫病防控难度日益增加,成为制约畜牧业健康发展的重要因素。改变传统疫病防控模式、实施疫病净化是综合提升养殖场生物安全水平和动物抗病能力的有效手段,是推动养殖业持续向好发展的重要基础。本文就种畜禽场疫病净化现状进行分析并提出建议。     

羊痘病毒的研究进展

从羊痘的流行特点、羊痘病毒基因组结构特征、热点蛋白研究、羊痘的诊断和检测、疫苗研究五个方面进行了较为详细的综述,以期为羊痘病毒的研究及预防控制羊痘提供参考。     

牛、羊包虫病及其实验室诊断技术

包虫病(echinococcosis)是由寄生于终末宿主(犬、狼、狐狸等)小肠的棘球蚴感染中间宿主(牛、羊、猪、骆驼、人类等)而引起的一种严重的人兽共患寄生虫病。该病在临床表现上缺乏特异性,且多为隐性感染,病原体不易检出,严重危害牧区人民健康和畜牧业发展。对包虫病的病原学特点、流行病学特点、实验室检测和诊断技术作一介绍,以期为该病的预防控制和进一步研究提供参考。     

DNA fingerprinting of Australian isolates of Mycobacterium avium subsp paratuberculosis using IS900 RFLP

OBJECTIVES: To evaluate additional restriction enzymes for IS900 RFLP of Mycobacterium avium subsp paratuberculosis and examine the genetic diversity among Australian isolates for epidemiological studies of Johne's disease. DESIGN AND PROCEDURE: Seventy-one isolates of M paratuberculosis from cattle, sheep, goat, alpaca and rhinoceros in six Australian States and the Northern Territory, reference strains and reference DNA from previously characterised strains were tested for genetic variation. Bst EII, Pvu II and Pst I restriction enzymes were used, and four others (Bam HI, Alu I, Xho I and Dra I) were assessed for their ability to detect polymorphisms. Multiple isolates from some animals were tested. RESULTS: Bam HI, was the most effective enzyme for identifying polymorphisms (12 types), followed by Bst EII (11 types). Both Pvu II and Pst I were relatively ineffectual. Fifteen different types were identified, 12 in clinical isolates. Most isolates were cattle (C) strains and fell into the C1 (n = 28) and C3 (n = 32) groupings. All isolates from alpaca were type C1, and bovine isolates were commonly C1 (n = 15) or C3 (n = 28). All of the sheep were infected with sheep (S) strains; no S strains were identified in cattle. Two of six isolates from one animal had single band differences. CONCLUSION: The epidemiological features of M paratuberculosis in Australia are similar to those reported in New Zealand, where cattle and sheep are commonly infected with different strains. However, because of the lack of polymorphism identified within the major groups, it is unlikely that DNA fingerprinting will have a significant role in epidemiological studies of Johne's disease, unless an unusual strain in being studied.     

Control of clinical paratuberculosis in New Zealand pastoral livestock

This review summarises current control measures for clinical paratuberculosis (Johne’s disease; JD) in New Zealand pastoral livestock. Most New Zealand sheep, deer, beef and dairy cattle herds and flocks are infected by Mycobacterium avium ssp. paratuberculosis (Map). Dairy cattle and deer are mostly infected with bovine (Type II), and sheep and beef cattle with ovine (Type I) strains. Control in all industries is voluntary. While control in sheep and beef cattle is ad hoc, the dairy and deer industries have developed resources to assist development of farm-specific programmes.

The primary target for all livestock is reduction of the incidence rate of clinical disease rather than bacterial eradication per se. For dairy farms, a nationally instituted JD-specific programme provides guidelines for risk management, monitoring and testing clinically suspect animals. While there is no formal programme for sheep farms, for those with annual prevalences of clinical disease >2%, especially fine wool breeds, vaccination may be a cost effective control option. The deer industry proactively monitors infection by a national abattoir surveillance programme and farmers with an apparent high disease incidence are encouraged to engage with a national network of trained consultants for management and control advice. Evaluation of the biological and economic effectiveness of control in all industries remains to be undertaken. Nevertheless, opportunities exist for farmers, who perceive significant JD problems in their herds/flocks, to participate in systematic best-practice activities that are likely to reduce the number of clinical infections with Map on their farms, and therefore the overall prevalence of JD in New Zealand’s farming industries.