Two Akabane virus glycoprotein Gc domains induce neutralizing antibodies in mice

Akabane virus (AKAV), belonging to the genus Orthobunyavirus and family Peribunyaviridae, causes reproductive and congenital abnormalities in ruminants. Its envelope glycoprotein Gc is a neutralizing antigen, on which at least five distinct antigenic regions have been identified. We attempted to identify the domains using truncated recombinant AKAV Gc proteins expressed in Escherichia coli and monoclonal antibodies (mAbs) with AKAV-neutralizing activity. Dot blot analysis revealed that amino acid positions 1–97 and 189–397 (Gc_1–97 and Gc_189–397) in the truncated recombinant proteins reacted with the mAbs. Additionally, AKAV was neutralized by sera from mice immunized with these recombinant proteins. The results suggested that the two domains contain neutralizing epitopes and could be potential subunit vaccines against AKAV.     

应用间接荧光抗体技术研究水中嗜水气单胞菌的数量与鱼类出血性败血病的关系

应用间接荧光抗体技术（ＩＦＡＴ），并结合嗜水气单胞菌（Ａｈ）地区优势血清型，对鱼类出血性败血病的致病菌Ａｈ进行水中数量的测定。ＭＭ感染试验和对生产鱼塘调查的结果表明，水中Ａｈ菌量与疾病呈正相关，致病浓度又随鱼体健康低下、水中氨氮偏高、溶氧偏低等多种因子的影响而下降。本试验方法快速简便，检测对象为水体，非常适用于预测疾病的发展趋势。     

In vitro studies on feline panleucopaenia virus. Standardisation of haemagglutination-inhibition test for feline panleucopaenia virus antibody

Standardised procedure for obtaining reproducible haemagglutination-inhibition results for FPV antibody which correlate with serum-neutralization titres was described. Optimal conditions were found to be Alsevers anticoagulant, PBS/0.05% BSA (pH 6.8) as buffer, especially washed round bottom microplates, determination of maximally sensitive porcine erythrocytes, use of reproducible erythrocyte concentrations, inactivation of serum samples at 56 degrees C for 30 min and serum treatment with koalin pH 9.0. The concentration of erythrocyte used for estimation of haemagglutination units in H1 test should not differ from that used as indicator in the test. Predilution of serum beyond 1:4 associated with false results. Reproducible method for removing natural agglutinins in serum by adsorption with erythrocytes was described.     

A prospective,randomized, double-blind,placebo-controlled multisite,parallel-group field study in dogs with osteoarthritis conducted in the United States of America evaluating bedinvetmab,a canine anti-nerve growth factor monoclonal antibody

ObjectiveBedinvetmab, a fully canine anti-nerve growth factor monoclonal antibody, was evaluated in dogs for control of osteoarthritis-related pain in a study conducted to support registration in the USA.Study designRandomized, double-blind, placebo-controlled, multicenter, parallel-group study.AnimalsGeneral practice client-owned dogs with osteoarthritis (n = 272).MethodsDogs were block randomized 1:1 to placebo (saline, n = 137) or bedinvetmab (n = 135; 0.5–1.0 mg kg^–1) administered subcutaneously, once monthly. The primary end point, day 28 Canine Brief Pain Inventory (CBPI) treatment success (TS), required pain severity score (PSS; 0–10) decrease ≥1 and pain interference score (PIS; 0–10) decrease ≥ 2. CBPI TS rates [and number needed to treat (NNT)], change in scores [and standardized effect size (ES)], change in quality of life (QoL) and bedinvetmab half-life were calculated.ResultsSignificant (p < 0.05) improvement with bedinvetmab over placebo occurred (days 28, 42, 56, 84) for CBPI TS. Of cases evaluable for day 28 CBPI TS (placebo, n = 131; bedinvetmab, n = 128), success rates were 36.6% and 47.4%, respectively (p = 0.0410) (NNT, 9.3; PSS and PIS ES, 0.3). CBPI TS increased after the second dose in both groups, plateaued for bedinvetmab at day 42 and decreased for placebo beginning day 84. Day 84 NNT (4.3), PSS (0.4) and PIS (0.5) showed continued improvement with monthly dosing. After the first dose, mean (± standard deviation) bedinvetmab half-life was 19.1 (8.3) days. Adverse events were similar between groups and not considered treatment-related. There was a significant effect of bedinvetmab versus placebo on all CBPI components (PIS, PSS, QoL).Conclusions and clinical relevanceThese results corroborated those previously reported and provide further support of safety and effectiveness of bedinvetmab (0.5–1.0 mg kg^–1) administered subcutaneously at monthly intervals to dogs for control of osteoarthritis-related pain.     

日粮脂肪来源对肉鸡免疫功能的影响

肉鸡日粮中分别添加７％的猪油、玉米油、亚麻子油和鱼油,检测血清抗ＳＲＢＣ抗体滴度和伴刀豆球蛋白Ａ（ｃｏｎＡ）、商陆分裂素（ＰＷＭ）对脾脏淋巴细胞的增殖反应。结果表明,四种脂肪对抗体生成有明显促进作用,其中以鱼油作用更显著;四种脂肪亦可明显促进脾脏淋巴细胞增殖,但脂肪种类对促进淋巴细胞增殖作用差异不大;鱼油可促进肉鸡生长,其余三种脂肪对肉鸡体重影响不大。     

慢性氨气暴露对肉鸡NK细胞杀伤活性和血清新城疫抗体效价和溶菌酶的影响

为探讨氨气对肉鸡免疫功能的影响,选择240只1日龄AA肉公鸡,随机分成4个处理组,分别饲养在4个独立的、环境可控制的实验舱内。4个环控仓氨气浓度设计为0～3周龄分别为0、13、26mg/kg和52mg/kg;3～6周龄分别为0、20、40mg/kg和80mg/kg。结果表明:高浓度氨气暴露3周和6周,肉鸡血清溶菌酶均表现降低,其中3周龄溶菌酶降低较显著(P<0.05);肉鸡氨气暴露6周后,NK细胞杀伤活性显著下降(P<0.05),新城疫弱毒疫苗免疫效能显著降低(P<0.05)。这一结果表明肉鸡暴露在高浓度氨气环境中,其免疫功能会表现降低。     

仙游县猪口蹄疫免疫效果检测与分析

通过对仙游县2014年秋季猪O型口蹄疫免疫抗体检测,了解和掌握仙游县猪口蹄疫免疫效果,以更好地指导今后动物疫病防控工作。     

氨苄青霉素单抗鉴定与酶联免疫检测方法的初步研究

利用碳化二亚胺(EDC)法将氨苄青霉素(AMP)与匙孔嘁血蓝蛋白(m cKLH)偶联制备免疫原免疫Balb/c小鼠,应用杂交瘤技术将免疫鼠脾细胞与小鼠骨髓瘤细胞(SP2/0)融合,建立分泌氨苄青霉素单克隆抗体的杂交瘤细胞株。杂交瘤细胞染色体数目为97~104条,3D12株亚型为IgG2 a,用其制备的腹水ELISA效价达到2×106。亲和常数为3×10-10mol/L,抗体相对分子质量为1.54×105,与其他抗生素的交叉反应率小于0.01%。采用间接竞争ELISA方法建立检测AMP的标准曲线,在0.5~100 ng/mL范围内呈线形相关,回归方程为Y=0.056 9X+0.130 8,相关指数R2=0.994 8,以10%抑制率对应的浓度计算,该方法对AMP的检测限为0.3 ng/mL,对市售消毒纯牛奶模拟样品最低检测限为0.4 ng/mL。     

Virulence-associated trimeric autotransporters of Haemophilus parasuis are antigenic proteins expressed in vivo

Glässer’s disease is a re-emerging swine disease characterized by a severe septicaemia. Vaccination has been widely used to control the disease, although there is a lack of extended cross-protection. Trimeric autotransporters, a family of surface exposed proteins implicated in host-pathogen interactions, are good vaccine candidates. Members of this family have been described in Haemophilus parasuis and designated as virulence-associated trimeric autotransporters (VtaA). In this work, we produced 15 recombinant VtaA passenger domains and looked for the presence of antibodies directed against them in immune sera by immunoblotting. After infection with a subclinical dose of H. parasuis Nagasaki, an IgG mediated antibody response against 6 (VtaA1, 5, 6, 8, 9 and 10) of the 13 VtaA of the Nagasaki strain was detected, indicating that they are expressed in vivo. IgA production against VtaA was detected in only one animal. VtaA were more likely to be late antigens when compared to early (Omp P5 and Omp P6) and late (YaeT) defined antigens. Antibody cross-reaction with two orthologs of Nagasaki’s VtaA5 and 6, VtaA15 and 16 of strain HP1319, was also detected. No antibodies against VtaA were detected in the sera of animals immunized with a bacterin of the Nagasaki strain, suggesting poor expression in the in vitro conditions used. Taken together, these results indicate that VtaA are good candidate immunogens that could be used to improve H. parasuis vaccines. However, their capacity to confer protective immunity needs to be further studied.