牛支原体疫苗的研究进展

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。     

牛支原体疫苗的研究进展

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。     

肉牛常见呼吸道疾病的防控

近年来,我国部分省区先后发生了多起牛呼吸道传染病疫情。牛呼吸道传染病是由牛支原体、牛巴氏杆菌和一些病毒混合感染引起的疾病。牛支原体感染牛上呼吸道疾病后会导致牛呼吸道黏膜抵抗力下降。需要加强管理,对犊牛要进行科学合理的免疫,对于细菌性的呼吸道疾病主要使用注射抗生素的方法进行治疗,减少疾病对正常生产的影响。     

犊牛支原体病的诊断与防控措施

在疫病防控中,牛支原体是一种很容易被忽视的病原,其能造成奶牛产生各种疾病,如子宫内膜炎、乳腺炎、肺炎、关节炎、生殖道炎症等,给牧场带来严重的经济损失。犊牛感染支原体后会产生呼吸道疾病、耳炎、关节炎等,造成其生长发育受阻。对犊牛感染支原体的症状、诊断与防控措施进行综述。     

牛病毒性呼吸道疾病诊断技术研究进展

近些年来,我国牛呼吸道疾病病原不断增加,牛呼吸道疾病已经发展成为多种病原混合感染的牛呼吸道综合征,其中有多种病毒、细菌及支原体参与疾病的发生.论文讨论了牛病毒性腹泻、牛传染性鼻气管炎、牛副流感、牛呼吸道合胞体病等牛主要病毒性呼吸道疾病的实验室诊断技术.分别从单一传染病的病原学、血清学、分子生物学方面讨论主要的实验室诊断技术,又从多病原混合感染的方面介绍了当前主要的多重诊断技术,为牛呼吸道疾病的防控提供参考.     

肉牛牛支原体肺炎感染的细菌学研究

[目的]牛支原体肺炎是严重危害国内外肉牛养殖业的一种重要疾病,病原混合感染将加剧病情,增加临床治疗难度。本研究通过阐明我国牛支原体肺炎混合感染情况,为探讨更加有效的防控手段提供参考依据。[方法]近4年来采用门诊和出诊的方式,收集了全国范围内35个临床初诊为牛支原体肺炎的牛场病牛样本,进行牛支原体及混合感染细菌的分离和分型鉴定。[结果]确定了这类疾病的细菌学感染特征,表现为牛支原体感染占绝对优势,混合感染模式主要以牛支原体合并多杀性巴氏杆菌A型感染、牛支原体合并和化脓隐秘杆菌感染为主。[结论]经实验室检测证实临床初诊病例绝大部分为牛支原体肺炎,但混合感染很普遍。     

牛支原体感染的预防与治疗

肉牛养殖是现代畜牧业发展的重要方向之一,通过肉牛养殖能够带动地方经济发展,增加养殖户的经济收入。但肉牛养殖需要做好多方面的管理工作,其中疫病防控就是管理工作的重点。牛支原体感染是一种常见的牛呼吸道疾病,也是影响肉牛健康的重要疾病之一,对该病防控的重点是早期预防,同时还要做好对病牛的治疗。本文对该病的病原、发病机理、诊断方法等进行了介绍,并给出了该病的治疗方法与预防措施,以帮助养殖户降低牛支原体感染的发病率,保证养殖收益。     

牛呼吸道疾病的病原学与防制措施研究

<正>牛呼吸道疾病是牛规模化养殖中常见疾病,发病急、死亡率高,严重威胁牛群健康,并且给养殖场带来经济损失。要对牛呼吸道病的病原进行研究,并且进行防制,解决牛群养殖中常见的呼吸道疾病,保证养殖场的经济收益,促进养殖业健康发展。1牛呼吸道疾病的主要病原1.1支原体支原体是一种主要存在于牛的肠道、呼吸道以及生殖道等部位的类似于细菌的原核微生物,是导致肉牛和奶牛患呼吸疾病的主要病原,支原体受到温度的限制,高温能够抑制支原体的活性。当牛感染支原体病原的呼吸道疾病时会出现精神萎靡、食欲不振、呼吸较原来粗重并且咳嗽流鼻涕,还有一部分患牛会产生腹泻粪便呈水样并且带有血丝现象,更严重会继发关节炎或者结膜炎。而且感染支原体呼吸疾病的牛死亡率高达50%,     

牛呼吸道疾病综合征病例的病原分析

本试验旨在查清广西某牛场1起牛呼吸道疾病综合征(BRDC)病例的病原,指导牛场进行疾病防控。采取现场调查、临床症状与病理变化、病原分离鉴定等方法对病例病原进行分析,根据病原药敏试验结果进行治疗。从病例的肺脏组织中分离到1株支原体和1株革兰氏阴性致病杆菌。支原体分离株在PPLO固体培养基上可见典型的"煎蛋样"菌落,PCR扩增出牛支原体oppF基因特异性的448 bp目的片段,其oppF基因序列与美国分离的牛支原体国际标准株PG45的核苷酸序列同源性为98.4%。革兰氏阴性细菌分离株生化特性符合黏质沙雷氏菌特性,其16S rRNA基因PCR扩增出1 400 bp的目的片段,测序结果与GenBank上登录的黏质沙雷氏菌的核苷酸序列同源性达到99.0%,对小鼠具有致病性。牛支原体和黏质沙雷氏菌分离株均对壮观霉素、阿奇霉素、阿米卡星、庆大霉素和新霉素高度敏感,用高敏药物壮观霉素联合地塞米松等相关措施进行治疗,收到良好效果。结果表明,引起这次牛呼吸道疾病综合征的病原为牛支原体和黏质沙雷氏菌。     

山东地区发生呼吸道性疾病的肉鸡场鸡毒支原体的分离鉴定

为了解山东省发生呼吸道疾病的肉鸡场鸡毒支原体的感染情况,2013年至2014年从山东地区发生呼吸道疾病的商品肉鸡场采集发病鸡,记录其临床表现(发病特点、临床症状和病理变化),并进行鸡毒支原体分离鉴定。对符合鸡毒支原体培养特性的分离株通过PCR扩增和测序加以鉴定,共分离鉴定出36株鸡毒支原体。3~20日龄肉鸡采集23场,分离出3株鸡毒支原体,分离阳性的样品疑来自鸡毒支原体单纯感染的病例;21~40日龄肉鸡采集78场,分离出33株鸡毒支原体,分离阳性的样品均来自混合感染病例。     

支原体和肺支原体双通道荧光定量PCR法检测鼠支原体感染试验

采用TaqMan探针法支原体通用型和肺支原体特异型双通道荧光定量PCR法,对清洁级SD大鼠150只I、CR小鼠120只,C57小鼠100只,普通级SD大鼠104只I、CR小鼠97只,C57小鼠76只,检测支原体和肺支原体感染情况。清洁级SD大鼠中检测到1只支原体阳性;清洁级ICR小鼠和C57小鼠中支原体和肺支原体未见阳性;普通级SD大鼠中检测到2只支原体阳性,1只肺支原体阳性;普通级ICR小鼠中检测到1只支原体阳性,2只肺支原体阳性;普通级C57小鼠检测到1只支原体阳性。表明清洁级实验动物大鼠中仍然存在支原体感染;普通级实验动物大鼠和小鼠支原体感染明显高于清洁级动物。     

绵羊肺炎支原体标准株Y98与丝状支原体丝标准株PG3、绵羊肺炎支原体分离株HD-1、标准株FH抗原的差异性研究

试验采用SDS—PAGE和免疫印迹分析技术研究了绵羊肺炎支原体标准株Y98与绵羊肺炎支原体分离株HD-1、丝状支原体丝状亚种PG3以及肺炎支原体标准株FH间细胞膜蛋白免疫原性的异同。结果表明：绵羊肺炎支原体标准株Y98同绵羊肺炎支原体分离株HD-1间细胞膜蛋白免疫印迹结果基本一致,而绵羊肺炎支原体标准株Y98与丝状支原体丝状亚种PG3和肺炎支原体标准株FH抗原差异较大,缺乏共同抗原成分。     

Biochemical Characterization of Mycoplasma bovirhinis,Mycoplasma dispar and Recent Bovine Isolates of Mycoplasma canis

The pattern and kinetics of substrate utilization by the type strains of Mycoplasma canis, M. bovirhinis and M. dispar and ten recent M. canis isolates from cattle were determined. Metabolism of a range of sugars and organic acids by M. dispar was detectable by measurement of oxygen uptake. Organic acids were not utilized by M. bovirhinis or M. canis, and there was no oxygen uptake during metabolism of glucose or other sugars, as monitored by a pH-change method. The M. canis strains varied in their ability to metabolize sugars; seven of the isolates from cattle had the distinctive ability to metabolize sucrose, and one isolate, plus the type strain (from a dog), metabolized N-acetylglucosamine. The M. bovirhinis strain metabolized maltose. However, all the test strains oxidized glycerol at high rates and with a high affinity. Oxidation of glycerol has been reported for other mycoplasmas from the bovine respiratory tract and leads to the production of hydrogen peroxide, a potential virulence factor.     

Growth and interaction of Mycoplasma bovirhinis and Mycoplasma dispar in vitro

Two mycoplasmas were grown in pure and mixed cultures in glucose calf-serum broth with initial pH 7.8. Sensitivity to pH was also tested. The main data for Mycoplasma bovirhinis and Mycoplasma dispar, respectively, in pure cultures were as follows: lag phase, days: <1, 1–2; log phase: 1–2, 1–4; relatively stationary phase: 0–1, 2–4; decline phase (to the extent roughly logarithmic): 2–6, 5–10; maximal titers: 5 × 10⁷ to 10⁹, 5 × 10⁶ to 10⁸ color changing units per 0.2 ml; highest pH, approximately, at which decline started: 7.7 and 7.0; definitely toxic initial pH: 5.6, 6.8; relative production of acidity; less, more. Decline either shortly ended in loss of viability or, correlated with higher pH levels, led to a prolonged maintenance in lower numbers. The decline of M. bovirhinis was postulated to be essentially caused by an autotoxic product/products other than H⁺.

In mixed cultures an antagonistic effect due to the faster growing M. bovirhinis against M. dispar was recorded. The effect varied according to the initial numbers of organisms and their ratio. Two mechanisms seemed to be active: 1. decrease of pH somewhat below neutrality led to the death of the sensitive M. dispar; 2. M. dispar, when present in relatively high initial numbers, was inhibited by M. bovirhinis during the latter's logarithmic growth at pH-levels above 7.0, the inhibition ending shortly afterwards. A rapidly inactivated product/products of M. bovirhinis metabolism, inhibitory to M. dispar was posited. The results offer an improved insight into diagnostic practices for M. dispar.     

Identification of species-specific and interspecies-specific polypeptides of Mycoplasma gallisepticum and Mycoplasma synoviae

Temporal antisera (TA) prepared in susceptible Leg-horn-type chickens against Mycoplasma gallisepticum and M synoviae were evaluated to determine the extent of cross-reactivity in ELISA and hemagglutination inhibition tests. Species-specific and interspecies-specific polypeptides were identified after electrophoretic separation and protein immunoblotting with reference antisera, TA, and a monoclonal antibody specific for M gallisepticum. Mycoplasma gallisepticum antiserum cross-reacted with M synoviae polypeptides in ELISA and TA immunoblots. Two major M synoviae polypeptides (88 and 53 kilodaltons [kD]) cross-reacted with M gallisepticum antisera in TA immunoblots. An M gallisepticum polypeptide of 70 kD cross-reacted with M synoviae in TA immunoblots. In contrast, M gallisepticum and M synoviae reference antisera cross-reacted when immunoblotted with heterologous antigens. A monoclonal antibody specific for M gallisepticum bound to a 69-kD polypeptide in lectin-purified and whole-cell M gallisepticum protein fractions in immunoblot assays. The lectin-purified fraction hemagglutinated chicken RBC. Seemingly, the 69-kD polypeptide may constitute all or part of the M gallisepticum hemagglutinin.     

Utilisation of glucose by Mycoplasma suipneumoniae and Mycoplasma flocculare.

The utilisation of glucose by Mycoplasma suipneumoniae and Mycoplasma flocculare was examined by chemical determination of glucose disappearance during growth, and by examination for hexokinase activity in cell preparations. Both species degraded glucose during growth and possessed hexokinase activity as evidence of the presence of a glycolytic pathway. The glucose utilisation capacity was found to be greater for M. flocculare than for M. suipneumoniae.     

Genetic and antigenic relatedness between Mycoplasma gallisepticum and Mycoplasma synoviae

The two avian pathogens Mycoplasma gallisepticum and Mycoplasma synoviae were found, by Southern blot hybridization of their digested DNAs, to share genomic nucleotide sequences additional to those of the highly conserved ribosomal RNA genes. The assumption that some of the shared sequences encode for antigens or epitopes common to both mycoplasmas was supported by Western immunoblot analysis of cell proteins of one mycoplasma with specific antiserum to the other mycoplasma. Interestingly, the band patterns of reactive antigens were different for some of the M. gallisepticum strains, supporting the concept that the species is genotypically variable. The results of the present study may explain the cross-reactivity of the two mycoplasmas noted previously in a variety of routine serological tests.     

应用多重套式PCR检测鸡毒支原体和鸡滑液囊支原体

根据已发表的鸡毒和鸡滑液支原体血凝素基因序列pMGA和vlhA各设计两对引物,建立鉴别诊断两种支原体的多重套式PCR方法,对其进行温度条件、Ⅱ步模板浓度优化及特异性、敏感性实验。该方法在两步PCR后能特异性地扩增出MG(408 bp)和MS(688 bp)两个目的片段。应用于临床样品检测,与支原体分离、SPA检测比较结果PCR灵敏度高于病原分离。