牛结核病的流行与防控技术

一、牛结核病的防控概述1.结核病是人兽共患的慢性消耗性传染病。病原是分枝杆菌中的结核分枝杆菌复合群,其中人结核病是由结核分枝杆菌(人型菌)引起,牛结核病是由牛分枝杆菌(牛型菌)引起。2.人感染牛结核的情况。(1)发达国家。美国牛奶巴氏消毒前(1908年),10%～30%的人结核病例是由牛分枝杆菌感染所     

浅谈牛结核病的防制措施

结核病是由结核分枝杆菌引起的人畜共患传染病,也是牛群中最常见的一种慢性传染病。在临床上以病牛贫血、消瘦、体虚乏力、精神萎靡不振和生产力下降等为特征。在牛的多种组织器官上形成结核结节和干酪样钙化病灶。1病原结核病病原菌为结核分枝杆菌,分为3型,即人型、牛型和禽型。其中以牛型对奶牛群致病力最强。牛型分枝杆菌长     

塔里木马鹿结核病的诊治

2007年新疆某规模马鹿场部分马鹿发病,仔鹿多表现为消瘦、食欲下降,营养消耗性死亡;成年鹿多表现为咳嗽、喘气、体温升高、突然喘气死亡。通过病理解剖,细菌培养,接种动物等方法确诊该鹿场马鹿死亡原因是感染了牛型结核分枝杆菌,说明牛型结核分枝杆菌可以感染马鹿。     

奶牛接种结核菌素疫苗发生过敏反应了

结核病是由结核分枝杆菌引起的一种人畜共患慢性传染病。奶牛最易感，结核病病牛是本病的主要传染源，健康奶牛可通过被污染结核分枝杆菌的空气、饲料、饮水等经呼吸道、消化道等途径感染。以肺结核、乳房结核和肠结核最为常见。临床以牛型结核分枝杆菌PPD（提纯蛋白衍生物）皮内变态反应实验监测奶牛是否感染分枝杆菌最为常用。笔者2009年在我县奶牛结核病普查时遇到一起典型病例报道如下：     

人用卡介苗对牛抗结核感染的效果观察

结核分枝杆菌分为人型、牛型和禽型3种分枝杆菌。牛结核病是由牛型结核分枝杆菌引起的人畜以及其他不同种属动物的一种慢性经过为主的人畜共患传染病。由于本病可在牛群之间,牛与野生动物和已驯化动物之间,牛与人之间、人与人之间相互交叉传染感染,所以本病在公共卫生学上具有     

牛结核病防治

结核病是由结核分枝杆菌引起的一种人畜共患的慢性传染病。 1 传染源和感染途径 结核病病牛和开放性结核病人是本病的主要传染源。牛型结核分枝杆菌通过开放性病牛的鼻汁、痰液、粪尿、乳汁和生殖器官的分泌物排出体外。健康畜通过被污染的空气、饲料、饮水经呼吸道、消化道等途径感染。     

牛结核的防制

牛结核病主要是由牛型结核分枝杆菌引起的一种人兽共患的慢性传染病。世界动物卫生组织(OIE)将其列为B类动物疫病,我国将其列为二类动物疫病。1病原结核病是由结核分枝杆菌引起的一种人畜共患的慢性传染病,结核分枝杆菌根据其致病性可分为人型、牛型、禽型和鼠型4种。其中以牛型对牛的致病性最强。结核分枝杆菌对湿热抵抗力弱,60℃30min即失去活性。但分枝杆菌因富含类脂和蜡脂,对外界环境的抵抗力较强,不会轻易被扑灭,3℃条件下可存活6￣12个月,即使是盛夏,也能在粪便中可存活2￣3天。在干燥的痰液中可存活6￣8个月,在冰点下能存活4￣5个…     

野生动物结核感染、检测与控制

结核病是一种人畜共患的疾病,现在全世界范围内造成成年人死亡居于首位。虽然结核分枝杆菌是人的最主要的感染原,但是由牛结核分枝杆菌引起的感染占一部分。牛型结核杆菌是牛及其他哺乳野生动物的病原菌,亦能使人致病。结核不仅对野生动物种群本身有直接的影响,而且又可以作为家畜的传染宿主而对家畜生产带来巨大的经济影响。况且如果它们成为人类感染的源头,那么野生动物的结核可能对人类的健康影响有重要的意义。本文关注于在感染的野生动物对家畜患有结核风险的评估、检测及防治,以期为预防、控制牛结核提供一些有效的措施。1野生动物结…     

奶牛结核病的诊断及防控措施

1流行病学本病可侵害多种动物,其中对牛型结核分枝杆菌最易感的是奶牛,其次是黄牛、水牛、牦牛。另外,还可感染猪、山羊、猫等家养哺乳动物和野猪、野牛、猴等50种温血脊椎动物和20多种禽类,人也不例外。结核病病牛和开放性结核病人是本病的主要传染源。牛型结核分枝杆菌是通过开放性病牛的鼻汁、     

牛结核病防控技术措施

正牛结核病(Bovine Tuberculosis)是由牛型结核分枝杆菌(Mycobacterium bovis)引起的一种人兽共患的慢性传染病,以组织器官的结核结节性肉芽肿和干酪样、钙化的坏死病灶为特征。结核分枝杆菌主要分三个型:即牛分枝杆菌(牛型)、结核分枝杆菌     

Progress in the development of vaccines and diagnostic reagents to control tuberculosis in cattle

The sharp rise of bovine tuberculosis (TB) in Great Britain and the continuing problem of wild life reservoirs in countries such as New Zealand and Great Britain have resulted in increased research efforts into the disease. Two of the goals of this research are to develop (1) cattle vaccines against TB and (2) associated diagnostic reagents that can differentiate between vaccinated and infected animals (differential diagnosis). This review summarises recent progress and describes efforts to increase the protective efficacy of the only potential TB vaccine currently available, Mycobacterium bovis BCG, and to develop specific reagents for differential diagnosis. Vaccination strategies based on DNA or protein subunit vaccination, vaccination with live viral vectors as well as heterologous prime-boost scenarios are discussed. In addition, we outline results from studies aimed at developing diagnostic reagents to allow the distinction of vaccinated from infected animals, for example antigens that are not expressed by vaccines like Mycobacterium bovis Bacille-Calmette-Guérin, but recognised strongly in Mycobacterium bovis infected cattle.     

Use of a macrophage cell line for rapid detection of Mycobacterium bovis in diagnostic samples

Mycobacterium bovis isolation on bacteriological media from suspected cases of bovine tuberculosis (TB) demands laborious and time-consuming procedures. Even polymerase chain reaction (PCR) and radiometric analyses are secondary procedures and not alternatives to bacteriological procedures. Therefore, there is a need to develop new techniques aimed at rapid M. bovis detection in diagnostic samples. The human macrophage cell line THP-1 was thus investigated in experiments of M. bovis propagation and isolation from reference lymph node suspensions. THP-1 cells were shown to support a high-titered propagation within 48h of minute amounts of both M. bovis BCG and fully pathogenic M. bovis strain 503. A semi-nested PCR for TB-complex-specific insertion sequence IS6110 revealed M. bovis infection in THP-1 cells. The same was true of a flow cytometry (FC) assay for expression of M. bovis chaperonin 10 in infected cells. The reduced time for isolation and identification of M. bovis (48-72h) and the consistency of the test results make the use of macrophage cell cultures attractive and cost-effective for veterinary laboratories involved in TB surveillance.     

Diagnosis of Mycobacterium bovis infection in calves sensitized by mycobacteria of the avium/intracellulare group

Because of the frequent exposure of cattle to mycobacteria of the avium/intracellulare group, an investigation was carried out into the possible repercussions thereof on the diagnosis of bovine tuberculosis. Three calves from a bovine tuberculosis-free herd, scored avian reactors in the gamma-interferon assay for bovine tuberculosis, were sedated and inoculated endotracheally with a virulent Mycobacterium bovis strain. Then, three other avian reactors were housed with the above donor calves. Mycobacterium bovis was isolated from the nasal swabs of the three endotracheally infected, donor calves. On these samples, TB complex-specific polymerase chain reaction (PCR) tests for IS6110 were also positive, albeit with a different time kinetics. The three contact-infected calves showed clear immunological signs of infection; however, their nasal swabs were always PCR-negative and only Mycobacterium avium was isolated. In the endotracheally infected donor calves there was a rise of the gamma-interferon responses to avian and bovine purified protein derivative (PPD) tuberculins, which reached the same stable plateau levels over the whole experiment. The above effect was also observed in the contact-infected calves, even though the response to avian PPD tuberculin always remained at a higher level. By using conventional bovine and avian PPD tuberculins, the comparative intradermal test was generally positive in endotracheally infected, as opposed to contact-infected calves; a positive intradermal test for M. bovis was obtained in two contact-infected calves by different bovine PPD tuberculins based on M. bovis bacillus Calmette-Guerin (BCG) secreted or somatic antigens. It was concluded that M. bovis infection may be concealed for some time in cattle sensitized by mycobacteria of the avium/intracellulare group and that different diagnostic procedures should be adopted for such animals.     

Recent advances in our knowledge of Mycobacterium bovis: a feeling for the organism

Significant and rapid progress has been made in our knowledge and understanding of Mycobacterium bovis since the last international M. bovis conference 5 years ago. Much of this progress has been underpinned by the completion of the genome sequence. This important milestone has catalysed research into the development of a number of improved tools with which to combat bovine tuberculosis. In this article we will review recent progress made in the development of these tools and in our understanding of the organism, its evolution and spread. Comparison of the genome sequence with those of other members of the Mycobacterium tuberculosis complex has enabled insights into the evolution of M. bovis. This analysis also indicates that the M. tuberculosis complex have the propensity to adapt to new host species. The use of high throughput molecular typing methods has revealed that the recent bovine tuberculosis epidemic in Great Britain is being driven by a number of clonal expansions, which cannot be explained by random mutation and drift alone. Completion of a number of mycobacterial genome sequences has allowed the development of antigen mining techniques that rapidly identify M. bovis-specific genes. These can then be used as reagents in the gamma interferon assay to increase the specificity of the assay and also to discriminate between Bacillus of Calmette and Guérin (BCG) vaccinated animals and those infected with M. bovis. In the longer term, comparisons between the genomes of M. bovis and BCG will allow insight into how BCG became attenuated following serial passage on artificial growth media and reveal clues into how to improve the vaccine efficacy of BCG.     

BCG vaccination against tuberculosis in European badgers (Meles meles): a review

Tuberculosis (TB) is a significant animal health problem in many parts of the world, and reservoirs of infection in wild animals complicate disease control efforts in farmed livestock, particularly cattle. Badgers (Meles meles) are a significant wildlife reservoir of Mycobacterium bovis infection for cattle in the United Kingdom (UK) and Republic of Ireland (ROI). Vaccination of badgers using an M. bovis strain bacille Calmette-Guérin (BCG) vaccine could potentially be an option in the national TB eradication strategy. Wildlife vaccination has been used successfully for other diseases in wildlife species, and may have a role to play in reducing M. bovis transmission at the wildlife-livestock interface. Research to date has provided evidence that BCG is protective in badgers, and a parenteral badger BCG vaccine has been licensed in the UK. Further research is required to develop effective strategies for vaccine deployment and to determine the effect of badger vaccination on cattle TB incidence.     

Vaccines designed to protect against Mycobacterium tuberculosis infection may aid the identification of novel vaccine constructs and diagnostic antigens for bovine tuberculosis

Vaccination has been identified as a promising control strategy for tuberculosis in both humans and cattle. Recent heterologous prime-boost approaches combining BCG vaccination with subunit boosts have shown considerable promise in both fields. However, the identification of further protective antigens is still a research priority. In this paper we have established the response hierarchy in Mycobacterium bovis infected or BCG vaccinated cattle of 6 Mycobacterium tuberculosis-derived proteins that were protective against M. tuberculosis in the guinea pig aerosol challenge model. Two of these proteins, Rv1806 and Rv3812, were recognised most frequently in cattle and therefore constitute potential subunit vaccine candidates that merit further evaluation in cattle. Their epitopes were mapped in infected cattle and were shown to be located primarily in the non-conserved regions of these PE/PE-PGRS protein family members. The aim of this study was to ascertain the presence of any correlation between the immunogenicity of defined antigens in different animal species. A weak association between guinea pig immunogenicity (as measured by protection) and antigenicity in M. bovis infected or BCG vaccinated cattle was found.     

结核分枝杆菌疫源追踪的基因检测分析

目的探讨牛源性人结核疫源追踪的基因分析方法。方法采用复方PCR结核杆菌快速鉴定技术,针对特征性分枝杆菌标志基因(MTP40基因、α抗原基因和IS6110),对结核病人和患牛的标本,进行检测。结果患者标本结核分枝杆菌阳性;患牛标本牛分枝杆菌和结核分枝杆菌分别阳性。结论结核病奶牛不仅是人类牛型结核的可能来源,也可能成为人类人型结核的潜在来源。     

Identification of Mycobacterium bovis isolates using a monoclonal antibody

A rapid immunoperoxidase slide assay for the identification of Mycobacterium bovis culture isolates is described. The monoclonal antibody used in this assay is specific for the M. tuberculosis complex of organisms. All M. bovis isolates tested, including 151 separate field isolates of M. bovis were positive as were 11 out of 12 M. tuberculosis strains and 4 out of 6 Bacillus Calmette Guerin (BCG) strains. One strain each of M. africanum and M. microti was negative. This assay provides a considerable improvement in both time and expense over the conventional methods of biochemical typing of M. bovis.     

BCG vaccination of neonatal calves: potential roles for innate immune cells in the induction of protective immunity

Bovine tuberculosis is a disease of increasing incidence in the UK causing major economic losses and with significant impact on bovine and, potentially human health: the causative agent Mycobacterium bovis is a zoonotic pathogen. Neonatal vaccination with the attenuated M. bovis Bacille Calmette Guerin (BCG) vaccine confers a significant degree of protection in cattle, and is a widely used control strategy for human TB. The adaptive immune system is relatively immature in neonates and increased numbers of innate effector cells present in young animals and human infants may compensate for this, enabling effective immune responses to vaccination. Natural killer cells and subsets of γδ TCR+ T lymphocytes secrete high levels of interferon gamma and can interact with antigen presenting cells to promote both innate and adaptive immune responses. These cell populations may be pivotal in determining immune bias following neonatal vaccination with BCG.