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1.
牛支原体疫苗的研究进展   总被引：2，自引：2，他引：0  
牛支原体（Mycoplasma bovis,M.bovis）是一种造成全世界范围内育肥牛和奶牛多种疾病综合征的重要病原体。临床症状主要包括长期性肺炎及多发性关节炎（CPPS）、呼吸道疾病综合征（BRD）、乳腺炎及生殖器官疾病。牛支原体能感染多种组织和器官,也能从健康的牛体内分离,是威胁畜牧业生产的主要病原体。由于临床上抗生素治疗效果不佳,预防或控制牛支原体感染最好的选择是研发有效的商业可用的疫苗。牛支原体疫苗的研究已历经多年,虽然存在很多问题,但也取得了一定进展。文章对牛支原体弱毒疫苗、灭活疫苗及亚单位疫苗的研究进展进行了总结,并讨论了疫苗设计的优化方案,为合理设计和研发有效的牛支原体防控技术提供参考。  相似文献   

2.
牛支原体耐药性研究进展   总被引：1，自引：1，他引：0  
在对国内外牛支原体的耐药性研究进展做以综述的基础上,对近年来支原体的耐药机制进行了概述,以期为养牛业生产中牛支原体病的防治和耐药机制的研究提供参考.  相似文献   

3.
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.  相似文献   

4.
The epidemiology, therapy, and prevention of M. bovis infections are briefly reviewed. In a survey begun in 1982, M. bovis was found frequently in the respiratory tract [corrected] of veal calves and beef cattle with respiratory problems. In replacement calves infected with respiratory disease in dairy herds, however, the organism has only been detected since 1986. Respiratory tract specimens collected from calves with respiratory disease were submitted for examination for M. bovis from 1986 to 1991 and originated from 83 herds. Mycoplasma bovis was detected in specimens from 59 of the herds, 20% of which were dairy herds and 80% fattening herds. Arthritis caused by M. bovis was observed in 12 herds until July 1991. Since 1976 when the first mastitis outbreak caused by M. bovis was diagnosed, M. bovis has caused 14 more outbreaks. The number of diseased cattle varied from 1 tot 16 per farm, and clinical signs of mastitis varied from mild to severe. In all instances the infection has been eradicated from the herds. Because M. bovis can cause great losses in intensively reared cattle herds, it is advisable to separate purchased veal calves and beef cattle from dairy cattle to prevent further spread of M. bovis.  相似文献   

5.
Infectious bovine keratoconjunctivitis (IBK), caused by Moraxella bovis, is a disease of major importance in cattle industry. M. bovis has several virulence factors among which pili are crucial antigen for the protective capacity of vaccines against this disease. The production of vaccines against IBK therefore requires a reliable technique for cellular piliation level assessment on cells to be included as vaccine components. In this study we describe a specific whole-bacterial cell enzyme-linked immunosorbent assay (bact-ELISA) capable of detecting pili antigen on M. bovis cell surface. A sequential competitive bact-ELISA was developed using highly piliated M. bovis cells as antigen. Samples to be analyzed were allowed to react with anti-pilus serum prior to incubation in wells coated with piliated cells of M. bovis. This assay proved useful for the rapid, sensitive and reproducible evaluation of piliation on M. bovis cells, and represents an important tool for cellular piliation monitoring daburing M. bovis cells production in stirred bioreactors.  相似文献   

6.
A safe, cost effective and accurate immunodetection technique for the rapid identification of Mycobacterium bovis colonies is described. One hundred and thirteen M. bovis isolates were differentiated from other species of mycobacteria using a M. bovis specific monoclonal antibody, with nitrocellulose membrane as the solid support. The technique confirms M. bovis identification in only 4 h compared to 3 weeks for conventional antibiotic sensitivity tests.  相似文献   

7.
AIM: To determine the relationship between the prevalence of macroscopic Mycobacterium bovis infection in feral ferrets (Mustela furo) and the abundance of brushtail possums (Trichosurus vulpecula). METHODS: The predictive power of a previously reported positive association between the prevalence of macroscopic M. bovis infection in ferrets and possum abundance was examined by undertaking surveys of M. bovis infection in ferrets at sites of low and high possum abundance. The association was then tested by a manipulative experiment that measured changes in the prevalence of macroscopic M. bovis infection in feral ferrets after reducing possum abundance. RESULTS: The positive relationship between the prevalence of macroscopic M. bovis infection in ferrets and possum abundance remained valid for new survey data, although the goodness of fit of the relationship was reduced. Experimentally reducing possum abundance reduced the odds of macroscopic M. bovis infection in ferrets by 80% in the years immediately following possum control (Odds Ratio=0.23, p=0.003). CONCLUSIONS: There is a causal link between possum abundance and the prevalence of macroscopic M. bovis infection in feral ferrets in areas in which M. bovis infection is known to occur in ferret populations. This suggests that possum-to-ferret transmission of disease occurs and accounts for most of the disease evident in ferret populations, though does not determine whether ferrets are spillover or maintenance hosts of M. bovis. Management to reduce the prevalence of M. bovis infection in ferrets should consider reducing possum abundance as a control tactic. KEY WORDS: Mustela furo, ferret, Trichosurus vulpecula, brushtail possum, Mycobacterium bovis, bovine tuberculosis.  相似文献   

8.
A highly sensitive and specific PCR (MB-PCR) was used in preliminary studies to detect M. bovis in milk samples to investigate its association with high somatic cell count (SCC), an indicator of subclinical mastitis and one of the factors in down grading the quality of milk. A total of 186 and 167 herds were tested with 43% and 62% of herds positive for M. bovis in Victoria and North Queensland, respectively. The quarter milks from 52 cows with persistently high SCC were tested by MB-PCR and culture to investigate the association of M. bovis with major mastitis pathogens (MMP). M. Bovis was detected in 77% of cows of which 19% alone had M. bovis without any other bacteria, 17% had M. bovis in combination with major mastitis pathogens and 40% had M. bovis in combination with non-major mastitis pathogens. We believe that M. bovis is widespread in dairy cattle and has the potential to produce disease alone or to predispose the udder to disease caused by major mastitis and environmental pathogens. These studies have revealed a hitherto unrecognised high prevalence of M. bovis in dairy cattle in North Queensland and Victoria in Australia. These initial studies also give a clear association between M. bovis and elevated somatic cell counts.  相似文献   

9.
Bovine tuberculosis caused by Mycobacterium bovis is a zoonotic infection with a wide range of mammalian hosts. In parts of the UK M. bovis infection in cattle is a persistent problem. The European badger (Meles meles) is implicated in the transmission of M. bovis to cattle, and is widely believed to constitute the most important reservoir of infection in UK wildlife. However, few studies have been carried out on the status of M. bovis infection in other UK mammals. In this review we present information on the incidence and pathology of M. bovis infection in UK wild mammals from both published and previously unpublished sources. Although the evidence does not support the existence of a significant self-maintaining reservoir of infection in any wild mammal other than the badger, there is a clear lack of sufficient data to rule out the involvement of other species. In the light of this and the dynamic nature of epidemiological patterns, further surveillance for M. bovis infection in UK wild mammals, using modern methods of diagnosis, is essential.  相似文献   

10.
An indirect ELISA was used to detect antibodies to Mycoplasma bovis in milk samples collected from a herd with M bovis mastitis. Antibodies were detected in samples from nine cows which had developed clinical M bovis mastitis. Milk from only three consistently antigen-negative cows tested positive for M bovis antibodies. These results indicate the potential value of the indirect ELISA for the detection of cows which have recently developed M bovis mastitis during the early stages of an outbreak.  相似文献   

11.
Sixteen Mycobacterium bovis (M. bovis) strains isolated from bovine tissues and one standard reference strain of M. bovis AN5 alongwith other species of mycobacteria for comparison were investigated for the presence of phenolic glycolipid (PGL) and phthiocerol dimycocerosate (PDIM) for rapid identification of M. bovis by thin-layer chromatography (TLC). The study indicated presence of PGL with an Rf value of 0.75 in chloroform-methanol solvent in all 17 M. bovis strains. The dimycocerostate A corresponding to spot A was the major constituent among all the three spots in M. bovis strains. TLC appeared to be a promising alternative to conventional biochemical methods for identification of M. bovis taking into consideration both PGL and PDIM lipids.  相似文献   

12.
Babesia bovis and Cowdria ruminantium were identified for the first time in cattle on Unguja Island, Zanzibar. B bovis is common and widespread, although clinical disease had not been diagnosed previously. The vector of heartwater, Amblyomma variegatum, is found throughout Unguja but C ruminantium appears to be more localised in distribution than B bovis.  相似文献   

13.
Digital dermatitis (DD) of cattle leads to lameness and a decrease of milk production and is responsible for major economic losses worldwide. Although a bacterial aetiology is generally accepted, it still is unclear which microorganisms cause and/or maintain the disease. Recently, a previously undiscovered bacterial species, Guggenheimella bovis, has been isolated from the front of two DD lesions in Swiss cattle and suggested as a potential pathogen. The aims of the present study were to determine the prevalence of G. bovis in 58 German cows suffering from DD via dot blot hybridization, and to analyse the spatial distribution of G. bovis within the affected tissue by fluorescence in situ hybridization (FISH). A species-specific probe, GUBO1, was designed and evaluated. In none of the 58 samples Guggenheimella could be detected, while cultured G. bovis was reliably identified by GUBO1. Further FISH experiments were carried out on two additional biopsies of Swiss cattle tested positive for G. bovis by quantitative PCR and permitted visualization of the newly discovered bacteria in situ. In these biopsies G. bovis proved to be tissue invasive forming characteristic spherical microcolonies not only within the bacterial biofilm but also in seemingly unaffected parts of the tissue not yet reached by the advancing bacterial front. Although the presence of G. bovis does not constitute an essential premise for DD, it seems likely that the bacterial species involved in DD vary, and that in some cases G. bovis is crucial for the development of DD lesions.  相似文献   

14.
The objective of this study was to isolate and identify Streptococcus bovis from yak, and detect their hemolytic, pathogenicity and antimicrobial susceptibility. 45 fecal samples collected from the diarrheal yaks in Aba state in Northwest Sichuan province were used to isolate Streptococcus bovis with sheep blood culture media under 37℃ and 5% CO2 condition cultured for 24 h. The isolated bacteria were identified by 16S rRNA amplification and sequencing. Total 14 Streptococcus bovis were identified, among which, 8 Streptococcus lutetiensis strains and 6 Streptococcus gallolyticus strains. 9 Streptococcus bovis strains showed α hemolytic, and 5 Streptococcus bovis showed β hemolytic. Both Streptococcus lutetiensis and Streptococcus gallolyticus caused the experimental mice mild diarrhea. The isolated 14 Streptococcus bovis were sensitive to penicillin, cefotaxime, vacomycin, acetylspiramycin, ciprofloxacin, rifampicin, teicoplanin, ampicillin and gentamicin, and highly tolerant to streptomycin, kanamycin, lincomycin, erythrocin, tetracycline and clindamycin.This study illustrated the biological characteristics of the isolated Streptococcus bovis from yak, which made the basis for the prevention and control of diseases caused by Streptococcus bovis.  相似文献   

15.
The authors screened 34 large cattle herds for the presence of Mycoplasma bovis infection by examining slaughtered cattle for macroscopic lung lesions, by culturing M. bovis from lung lesions and at the same time by testing sera for the presence of antibodies against M. bovis. Among the 595 cattle examined, 33.9% had pneumonic lesions, mycoplasmas were isolated from 59.9% of pneumonic lung samples, and 10.9% of sera from those animals contained antibodies to M. bovis. In 25.2% of the cases M. bovis was isolated from lungs with no macroscopic lesions. The proportion of seropositive herds was 64.7%. The average seropositivity rate of individuals was 11.3% but in certain herds it exceeded 50%. A probability model was developed for examining the relationship among the occurrence of pneumonia, the isolation of M. bovis from the lungs and the presence of M. bovis specific antibodies in sera.  相似文献   

16.
Modulation of host immune responses by protozoal DNA   总被引：1，自引：0，他引：1  
The pathology caused by acute Babesia bovis infection is similar to that seen in severe human malaria caused by Plasmodium falciparum infection, which is related to dysregulated production of inflammatory cytokines and nitric oxide (NO). We have observed induction of NO, inducible nitric oxide synthase (iNOS) and inflammatory cytokines in macrophages by B. bovis. Furthermore, proliferation of lymphocytes from individuals never exposed to certain protozoal pathogens can be induced by crude protozoal parasite extracts. We have repeatedly observed stimulation of naive PBMC from cattle to antigenic extracts of Babesia bovis. Based on recent studies demonstrating the mitogenicity of bacterial and other non-vertebrate DNAs for murine B cells and macrophages, the mitogenic properties of B. bovis DNA were examined. B. bovis and E. coli DNAs induced proliferation of PBMC and purified B cells from non-exposed cattle. Stimulatory activity was reduced by DNase treatment and methylation with CpG methylase, indicating the presence of stimulatory non-methylated CpG motifs in the B. bovis genome. B. bovis and E. coli DNAs enhanced IgG secretion by cultured B cells, stimulating IgG1 and more strongly, IgG2. Several hexameric CpG immunostimulatory sequences (ISS) active for murine B cells were identified in an 11 kb fragment of B. bovis DNA. An oligodeoxyribonucleotide containing one of these (AACGTT), located in the rhoptry associated protein-1 (rap-1) open reading frame, stimulated B cell proliferation. These studies identify a potential mechanism by which protozoal parasites may modulate host immune responses, leading to consequences such as hypergammaglobulinemia and splenomegaly. These results also support the use of ISS as vaccine adjuvants to enhance Type 1 immune responses in cattle.  相似文献   

17.
本研究旨在从腹泻牦牛粪便中分离鉴定牛链球菌,并分析其溶血性、对小鼠的致病性及对抗菌药物的敏感性。将川西北阿坝州45份腹泻牦牛粪便于血平板上划线,37℃、5% CO2培养24 h分离细菌,经16S rRNA序列扩增测序和系统发育分析鉴定出14株牛链球菌,其中8株巴黎链球菌,6株解没食子酸链球菌巴氏亚种;9株呈α溶血,5株呈β溶血。分离鉴定的牦牛源巴黎链球菌和解没食子酸链球菌巴氏亚种能引起试验小鼠的轻度腹泻;药敏试验结果显示分离菌株对青霉素、头孢噻肟、万古霉素、乙酰螺旋霉素、环丙沙星、利福平、替考拉宁、氨苄西林和庆大霉素共9种抗生素高度敏感,对链霉素、卡那霉素、林可霉素、红霉素、四环素和克林霉素耐药率较高。本研究阐明了牦牛源链球菌的部分生物学特性,为该病的防控奠定了基础。  相似文献   

18.
[背景]牛支原体是牛呼吸道疾病综合征的重要病因之一,可以引起牛的多种呼吸道疾病,给养殖业带来巨大的经济损失。接种疫苗是预防牛支原体感染的最有效的手段。[目的]通过人工感染牛体试验,了解牛支原体NM2012株的致病性,为后续疫苗研究提供生产用菌种。[方法]将牛支原体NM2012株第6代、第12代、第20代菌株分别经人工气管注射感染2周龄犊牛,攻毒后连续观察27 d,记录攻毒后犊牛的临床症状,在感染后第14天,从各攻毒组分别选取3头犊牛、空白对照组选取2头犊牛进行扑杀,第27天将剩余实验犊牛处死,观察肉眼病理变化和组织学病理变化。[结果]3个代次的NM2012菌株均对犊牛具有致病性,可引起比较典型的牛支原体肺炎症状和病理变化。[结论]NM2012株6-20代仍然具有对牛的致病性,可以作为今后疫苗研究的潜在菌种。  相似文献   

19.
A method for the evaluation of Mycobacterium bovis purified protein derivative (PPD) tuberculin in experimentally infected cattle is presented. The development of skin test responses in M bovis-infected cattle was determined for International Standard PPD-S, M bovis PPD-2, and M bovis PPD-5 at 24, 48, and 72 hours. Significantly larger reactions (dermal thickness) were observed at 48 and 72 hours than at 24 hours (P = 0.001). Statistically significant differences were not detected in the responses obtained with M bovis PPD-2, M bovis PPD-5, and International Standard PPD-S if comparisons were made at approximately the same concentrations in M bovis-infected cattle (P greater than 0.25). In Mycobacterium avium-infected cattle, M bovis PPD-2 produced skin test responses that were significantly smaller than responses obtained using M avium PPD-2 (P = 0.001). Significant variation was not observed in the PPD-S responses in 2 groups of M bovis-infected cattle (P greater than 0.1).  相似文献   

20.
The state of Michigan has recognized the presence of Mycobacterium bovis in its free-ranging white-tailed deer population since 1994. This endemic infection is primarily located in a 12-county area in the northeastern lower peninsula of Michigan. A statewide surveillance and eradication program of the disease has been in effect since 1994. Worldwide, Mycobacterium tuberculosis complex organisms have a known predilection toward development of antimicrobial resistance. The objective of this study was to investigate the antimicrobial susceptibility of M. bovis isolates from white-tailed deer in Michigan and detect any changes in susceptibility over time. M. bovis isolates from 2 fall hunting seasons (1999 and 2004) were used in this study. The fall season of 2004 marked the first documented case of direct transmission of M. bovis from a wild deer to a human in Michigan. Since M. bovis is a zoonotic disease, knowledge of susceptibility can expedite treatment options in humans. M. bovis isolates were obtained from 58 deer, 4 coyotes, 3 cattle, 2 raccoons, and 1 human case from the 2 years combined. Methods of susceptibility testing included 1% proportion agar plates and Bactec radiometric broth testing. M. bovis was found to be uniformly resistant to the antibiotic pyrazinamide; this resistance is common to all M. bovis isolates. No other antimicrobial resistance was found in any of the tested M. bovis isolates, which may be, in part, attributed to the lack of any significant treatment pressure in wildlife.  相似文献   

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