猪繁殖与呼吸综合征病毒A06株单克隆抗体的制备及鉴定

用纯化的猪繁殖与呼吸综合征病毒(PRRSV)A06株病毒抗原免疫Balb/c小鼠,取免疫小鼠脾细胞与SP2/0骨髓瘤细胞进行细胞融合.经间接ELISA方法筛选,有限稀释法克隆,获得4株稳定分泌特异性单克隆抗体的杂交瘤细胞株,分别命名为3D12、4E10、6E2和7G6.其细胞培养上清效价分别为1:256、1:512、1:512和1:256,小鼠腹水效价分别为1:1.024×106、1:2.048×106、1:1.024×106和1:2.048×106.亚型鉴定表明,3D12、4E10、6E2和7G6分别为IgG2b、IgG2b、IgG1和IgG2a.ELISA检测结果显示,4种PRRSV单克隆抗体仅与PRRSV反应,不与其他病毒反应,表明均为抗PRRSV的型特异性单克隆抗体.对单克隆抗体腹水液进行IgG提取纯化,SDS-PAGE电泳验证,仅出现两条清晰条带,无杂带出现,证明纯化效果较好.这4种单克隆抗体的获得,为建立PRRSV检测方法提供了强有力的工具.     

Bacterial infection of the lower respiratory tract in 34 horses

OBJECTIVE: To investigate associations between the bacteriology and aspects of history, clinical presentation, outcome and pathology of lower respiratory tract disease of 34 horses. PROCEDURE: Detailed aerobic and anaerobic bacteriological investigations were performed on clinical specimens from horses with pneumonia, lung abscessation and necrotic pneumonia with or without pleurisy in an attempt to identify those bacteria that might contribute to the initiation and progression of infection. RESULTS: Bacteria were cultured from 33 of the 34 horses. In ten cases, only aerobic/facultatively anaerobic isolates were cultured while aerobic/facultatively anaerobic bacteria and obligately anaerobic bacteria were isolated in the other 23 cases. Moderate to large numbers of anaerobic bacteria were isolated only when the estimated duration of illness was at least five days. Bacteria were not cultured from 12 of the pleural fluid samples but were always cultured from pulmonary samples (either transtracheal aspirates from live horses or pulmonary lesions at necropsy). Streptococcus equi subsp zooepidemicus was isolated in the three cases where only one bacterial species was cultured. In the other 30 cases, multiple species were isolated. These included most often and in greatest numbers, Streptococcus equi subsp zooepidemicus, Pasteurellaceae, Escherichia coli, anaerobic cocci, Eubacterium fossor, Bacteroides tectum, Prevotella heparinolytica, Fusobacterium spp, and pigmented members of the genera Prevotella and Porphyromonas. Aerobic/facultatively anaerobic organisms were isolated from 97% of horses, while obligately anaerobic organisms were cultured from 68% of horses. CONCLUSION: There was no association between the isolation of any specific bacterium and the outcome of disease. However, obligately anaerobic bacteria (such as anaerobic cocci, Bacteroides tectum, P heparinolytica and Fusobacterium spp) and the facultatively anaerobic species Escherichia coli, were recovered more commonly from horses that died or were euthanased than from those that survived. There was an association between failure of horses to recover from pleuropneumonia and delay in diagnosis and initiation of treatment.     

肉牛呼吸系统疾病的诊断与防治

肉牛呼吸系统疾病是由环境因素(如断奶、运输、混群、阉割、拥挤和通风不良)、宿主自身因素和病原体等诸多因素相互作用引发的呼吸系统综合症。罹病牛日增重减少、饲料转化率降低、胴体质量下降和防治成本增加。在肉牛养殖业中,该病发病率和死亡率均较高,对世界肉牛养殖业造成巨大经济损失。文章介绍了发达国家和我国对肉牛呼吸系统疾病诊断、治疗和预防的近期研究进展,旨在为其有效防治提供参考。     

淹水对紫花苜蓿南北方品种抗氧化酶和无氧呼吸酶的影响

以紫花苜蓿南方育成品种渝苜1号和北方地方品种新疆紫泥泉为材料,在幼苗长出4片真叶时进行淹水处理,在淹水的第10天测定植株的生物量,并分别在淹水的第0,2,4,6,8,10天测定叶片中的丙二醛(MDA)含量以及叶片抗氧化酶和根系无氧呼吸酶的活性,以探明两个品种对淹水胁迫的耐受性差异及其生理响应机制。结果表明,淹水胁迫使紫花苜蓿的生物量减少,但与新疆紫泥泉相比,渝苜1号生物量的降幅小。淹水时渝苜1号叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)等抗氧化酶活性比新疆紫泥泉的高,而叶片MDA含量比新疆紫泥泉的低;根系无氧呼吸酶活性在淹水胁迫中均增强,但渝苜1号的乙醇脱氢酶(ADH)和丙酮酸脱羧酶(PDC)活性增加明显,乙醇发酵更强;而新疆紫泥泉的乳酸脱氢酶(LDH)的活性增加更为突出,乳酸发酵强。淹水影响紫花苜蓿正常生长,但南方品种渝苜1号比北方品种新疆紫泥泉对淹水胁迫更具耐受性,因为前者具有比较高的抗氧化酶活性和比较强的乙醇发酵途径,有利于增强植株抗淹水胁迫能力。     

猪繁殖与呼吸综合征防控方法研究进展

猪繁殖与呼吸综合征(PRRS)是危害养猪业的一种高度传染性疾病,在临床上以母猪流产、死胎等繁殖障碍以及仔猪呼吸道症状和高死亡率为特征,给养猪业造成了严重的经济损失.目前,PRRS的诊断与综合防治技术已成为国内外兽医学家研究的热点.论文简要概述了近几年来我国对PRRS病原学、临床症状、诊断学及其防控等方面的研究进展,并对当前存在的问题进行了讨论.     

Cardiorespiratory effects of a 7° reverse Trendelenburg position in anaesthetized horses: a randomized clinical trial

Objective

To evaluate the cardiorespiratory effects of a 7° reverse Trendelenburg position (RTP) in anaesthetized horses.

Detection of Ureaplasma diversum in the upper airways of Australian feedlot cattle

Bovine respiratory disease (BRD) exerts a major impact on the beef cattle industry nationally and worldwide, with a range of aetiological factors impacting its pathogenesis. Previous research has focussed on an increasing number of bacteria and viruses that have been shown to play a role in eliciting disease. Recently, additional agents have been emerging as potential contributors to BRD, including the opportunistic pathogen Ureaplasma diversum. To determine if U. diversum was present in Australian feedlot cattle and if that presence was linked to BRD, nasal swabs were collected from a cohort of 34 hospital pen animals and compared to 216 apparently healthy animals sampled contemporaneously at feedlot induction and again after 14 days on feed at an Australian feedlot. All samples were subjected to a de novo polymerase chain reaction (PCR) assay targeting U. diversum in combination with other BRD agents. U. diversum was detected at a low prevalence in cattle at induction (Day 0: 6.9%, Day 14: 9.7%), but in a significantly greater proportion of cattle sampled from the hospital pen (58.8%). When considering the presence of other BRD-associated agents, co-detection of U. diversum and Mycoplasma bovis was most common in hospital pen animals receiving treatment for BRD. These findings suggest that U. diversum may be an opportunistic pathogen involved in the aetiology of BRD in Australian feedlot cattle, in combination with other agents, with further studies are warranted to identify if a causal relationship exists.     

Clinical course, diagnostic findings and necropsy diagnosis in dyspneic cats with primary pulmonary parenchymal disease: 15 cats (1996–2002)

Objective: Correlate the necropsy diagnosis with the history, diagnostic findings, and clinical course of dyspneic cats with primary lung parenchymal disease. Design: Retrospective study. Setting: Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania. Animals: Client‐owned cats over 6 months of age hospitalized in the Intensive Care Unit (ICU) with a primary problem of respiratory distress that had pulmonary parenchymal disease on thoracic radiographs, and a complete necropsy. Interventions: None. Measurements and main results: Cats included were assigned into 2 groups based on the pulmonary histopathology: inflammatory (n=8) and neoplastic (n=7) disease. No statistical difference was found between the groups with regard to age, body weight, clinical signs, duration of clinical signs, physical examination findings, thoracic radiography, duration of hospitalization, treatment, and outcome. Cats with neoplasia had a statistically higher mean total white blood cell count (26.60 k/μL±10.41) than those with inflammatory lung disease (11.59 k/μL±4.49; P=0.026). Cats with bacterial or viral pulmonary disease had a significantly shorter median duration of illness (5 days, range 1–7 days) than all other cats (30 days, range 7–365 days; P=0.0042). Ultrasound guided pulmonary fine‐needle aspiration (FNA) provided an accurate diagnosis in 5/5 cases. Conclusions: Forty‐seven percent of cats with pulmonary parenchymal disease had neoplasia. The clinical diagnosis was difficult to obtain ante‐mortem; lung FNA appeared to be the most helpful diagnostic tool in these cases.