人工感染猪弓形虫病血清抗体消长规律的研究

根据１０头人工感染猪ＩＨＡＴ和ＥＬＩＳＡ血清抗体检测结果表明，所有被检动物感染后第１４天血清抗体达到阳性滴度，第２１天抗体滴度达到高峰，第２８天开始下降。ＥＬＩＳＡ比ＩＨＡＴ抗体检出时间早，抗体滴度高，维持阳性抗体滴度的时间长。本试验研究结果表明，猪弓形虫病血清学诊断的最佳时间为感染后１４￣２８天。     

持续感染黄牛体内口蹄疫病毒抗原性和血清中和特性分析

以口蹄疫病毒O/Akesu/58毒株感染黄牛获得口蹄疫病毒持续带毒动物,定期分离黄牛食道/咽喉部黏性液体（O/P液）和血清,研究病毒分离毒株抗原基因变异及其血清中和特性,从基因水平和血清学方面研究口蹄疫病毒持续感染分离株的抗原变异性。用RT-PCR扩增分离株抗原基因VP1,分析VP1基因变异情况;用微量血清中和试验检测了口蹄疫病毒持续感染血清与对应动物分离毒株的中和特性,并用液相阻断ELISA方法检测了口蹄疫病毒持续感染血清的抗体水平变化,并对其相关性进行了分析。结果发现所有持续感染分离毒株的VP1基因核苷酸和氨基酸同源性都在98%以上,没有碱基缺失或插入现象;与O/Akesu/58的核苷酸同源性仅为85%左右,氨基酸同源性也仅为90%。持续感染分离株VP1基因有多处位点发生突变,其中有16个核苷酸位点发生一致突变,但只有2个位点造成氨基酸突变（I 56→T、A 210→E）;而持续感染分离毒株有4个核苷酸位点和3个氨基酸位点发生了颠换突变;同时证实不同时间分离株与对应血清都能相互中和,且中和作用能力随着时间延续呈下降趋势,最低为1∶80,具有较强的中和能力,这与LPB-ELISA检测结果基本一致。这说明口蹄疫病毒持续感染分离株抗原变异不显著,没有变异到动物自身血清不能识别的程度,而且分离毒株与自身动物血清具有较强的中和特性;在持续感染过程中,动物血清保持高水平抗体滴度,且持续感染毒株的分离与否与抗体水平没有显著相关性。     

麻鸭感染新城疫病毒HI抗体效价的比较研究

以ＮＤＶ强毒，弱毒分别感染麻鸭，３０天后检测其血清ＨＩ抗体水平，并与自然感染ＮＤＶ动物，对照组动物血清ＨＩ抗体水平作比较；强毒感染动物血清与其所产蛋卵黄上清ＨＩ抗体水平作比较，结果表明，麻鸭群为ＮＤＶ野毒感染；鸭群血清ＨＩ抗体水平检测，以５０％以上检样出现７（ｌｏｇ２）以上的ＨＩ效价，可作为鸭群为受ＮＤＶ野毒感染的标志；鸭卵黄不宜替代鸭血清作ＮＤＶＨＩ抗体检测。     

牛伪狂犬病的实验室诊断

对不明原因役牛猝死症病料组织触片镜检和分离培养皆未发现细菌，乳胶凝集试验检查发现3份送检血清皆为伪狂犬病病毒（PrV)抗体阳性，ELISA检测结果,其中2份为PrV gE抗体阳性，而且这2份血清PrV中和抗体也为阳性，以脑组织制备DNA模板进行PCR，扩增到特异性的PrVDNA片段，对健康成年兔接种病牛脑，肺等病科，表现典型的伪狂犬病症状，综合流行病学，细菌学，血清学，分子生物学和动物试验结果，确诊为牛伪狂犬病。     

ELISA检测三种家鸭试验性感染潜鸭艾美耳球虫的血清抗体

将潜鸭艾美耳球虫孢子化卵爱清洁、纯化，捣碎滤过制成可溶性抗原，用于ＥＬＩＳＡ检测番鸭、北京鸭和二者杂交种骡鸭试验性感染潜鸭艾美耳球虫后血清中抗体的变化。试验鸭于１１日龄每只口服接种孢子化卵囊７．５×１０４个，接种感染后第３天血清抗体的ＯＤ值开始上升，番鸭和骡鸭感染后第１０天血清抗体达峰值，而北京鸭的峰值出现较晚，在感染后第１７天。番鸭和骡鸭在试验期间血清抗体ＯＤ值有两个峰值：第２峰值番鸭出现在感染后第１７天，骡鸭在感染后第２０天。３种鸭血清ＩｇＧ的变化曲线与血清Ｉｇｓ的相近似，表明在家鸭感染球虫后血清ＩｇＧ在血清抗体Ｉｇｓ中占主要地位。同时各组的不感染健康鸭血清免疫球蛋白随日龄增大显缓慢增长，但明显低于接种感染鸭。     

牛呼吸道病毒性感染的IgM ELISA试验

研究了一种检测牛传染性鼻气管炎（IBR）和牛呼吸道合胞体（BRS）病毒IgM抗体的捕获ELISA。以针对牛IgM的第一单克隆抗体用作捕获抗体，而第二单克隆抗体用来测定特异性抗病毒抗体，用实验感染和自然感染动物的血清样品来评价这一方法。结果，用临床病症出现后5－10天的血清样品可论断出IBR和BRS病毒感染。     

麻鸭感染新城疫病毒HI抗体效价的比较研究

以 NDV 强毒,弱毒分别感染麻鸭,30天后检测其血清 HI 抗体水平、并与自然感染 NDV 动物、对照组动物血清 HI 抗体水平作比较;强毒感染动物血清与其所产蛋卵黄上清 HI 抗体水平作比较.结果表明.麻鸭群为 NDV 野毒感染;鸭群血清 HI 抗体水平检涮,以50%以上检样出现7(log_2)以上的 HI 效价,可作为鸭群已受 NDV 野毒感染的标志;鸭卵黄不宜替代鸭血清作 NDV HI 抗体检测.     

胸膜肺炎放线杆菌荧光抗体检测方法的建立

将表达的胸膜肺炎放线杆菌（APP）外膜脂蛋白（OmlA）纯化后免疫新西兰白兔，收集高免血清作为一抗，建立了间接荧光抗体检测方法（IFA）。同时用提纯IgG标记FITC，作为荧光抗体，建立了直接荧光抗体检测方法（FA）。这2种检测方法对血清1型～12型APP标准株检测结果均为阳性，而血清13型和15型APP标准株、副猪嗜血杆菌、多杀性巴氏杆菌、支气管败血性波氏杆菌、大肠杆菌、沙门氏茵、葡萄球菌和链球菌等其它相关细菌的检测结果均为阴性。IFA和FA对APP的最小检出浓度分别为5．32×10^4CFU／mL和4．17×10^5CFU／mL。TFA和FA对人工感染动物和139份临床送检病料进行检测，并与细菌学检测结果和apxlV-PCR进行比较。其中，上述4种方法检测实验感染动物样品结果均为阳性，有较好的符合率；临床可疑病料中，有36份（25．90％1为IFA阳性，29份（20．86％）为FA阳性，42份（30．22％）为PCR阳性，从7份（5．03％）病料中分离到本病原。这些初步研究结果表明，所建立的荧光抗体检测方法可以应用于APP感染的检测，在检出率方面优于细菌分离鉴定方法。     

猪伪狂犬病病毒疑似感染人的实验室诊断及分析

为给人感染伪狂犬病病毒(PRV)来源分析及其感染机理研究提供相关信息，对一例疑似感染PRV患者的血清、脑脊液、拭子及其工作猪场的病猪血清、组织等样品进行病原学、血清学检测及病毒分离，对其工作猪场开展流行病学调查，并采集患者同事血清样品进行PRV抗体检测。结果显示：病人样品经数字PCR检测均为PRV核酸阳性；病人发病后5～90 d内的血清样品均为PRV gB抗体阳性，gE抗体发病后18 d转为阳性并一直持续到发病后90 d；病人同事均未表现临床症状，其血清样品PRV gB抗体阳性率为22.2%,gE抗体均为阴性；从病人工作猪场的病猪样品中分离到PRV，且样品经荧光定量PCR核酸检测及ELISA抗体检测均检出阳性；病人工作猪场为PRV阳性场，病人及PRV gB抗体阳性同事均有直接接触病猪史。结果表明，患者感染的PRV来自其工作猪场猪群的可能性较大，人感染后表现出和动物感染相似的抗体消长规律。PRV对公共卫生的影响及其感染机制需进一步关注和研究。     

进境蓝舌病抗体阳性动物带毒分析及检疫处理研究

为评估进口蓝舌病病毒(BTV)抗体阳性动物的感染状态,分析其带毒风险,对从国外进口的9批19714头动物,无菌采集全血分离血清,采用竞争ELISA方法检测BTV抗体。对BTV抗体检测阳性的动物,采集抗凝血,采用OIE推荐的套式RT-PCR和荧光RT-PCR方法进行检测,同时将样品送往蓝舌病参考实验室进行病毒分离鉴定,以确定动物的蓝舌病感染状态。结果 9批动物中检出28头BTV抗体阳性动物,但核酸检测和病毒分离鉴定的结果均表明这些BTV抗体阳性动物并不携带有非感染性和感染性病毒粒子。结合9个批次的进口动物并无明显临床表现,且进口动物来源地也无蓝舌病(BT)的疫情发生,据此根据OIE《陆生动物卫生法典》条款,判定这些抗体阳性动物为带毒阴性。本研究通过对BTV抗体阳性动物的带毒分析,并结合OIE确定BTV感染的要求,对BTV口岸隔离检疫流程提出建议,以指导动物检疫工作,阻止病原经口岸传入。     

Measurement of class specific antibody against cryptosporidium in serum and faeces from experimentally infected calves

Anti-cryptosporidium antibody levels were measured in serum and faeces of experimentally infected calves. In serum, IgG was detectable six days after infection and remained elevated throughout infection. IgA and IgM in serum showed little change. IgG, IgA and IgM levels all rose in the faeces five or six days after infection and reached a peak between days 8 and 14 after infection and then declined.     

Humoral immune responses following experimental infection of goats with Mycoplasma capricolum subsp. capripneumoniae.

Goats housed in microbiologically secure facilities were experimentally endobronchially infected with Mycoplasma capricolum subsp. capripneumoniae (Mccp), causal agent of contagious caprine pleuropneumonia (CCPP). The animals were monitored over an 8-week period post-infection (p.i.). Elevated temperatures were observed 2-7 days p.i., reaching a maximum of 41.5 degrees C in one animal (1884). By 8 weeks p.i. the infection was successfully cleared, with no Mccp being recovered from the lungs, serum or nasal passages. Mccp was not isolated from serum throughout the experiment, either directly by culture or indirectly via polymerase chain reaction (PCR). Humoral immune responses against Mccp capsular polysaccharide (CPS) were generally poor when measured by ELISA. CPS antigen was present in the serum of all infected animals early in the infection (day 14 p.i.), although in one animal (1855) CPS antigen persisted throughout. This was the only animal to exhibit a serious cough (day 5-19 p.i.). Successful diagnosis of CCPP was achieved using two different types of latex agglutination test (CPS antibody and CPS antigen detection test), immunoblotting and a blocking ELISA, although the latter lacked sensitivity until later in the infection (35-40 days p.i.). Only a single animal (1855) was detected positive using the current complement fixation test (CFT). Strong immune responses to protein antigens were detected by IgG and IgM immunoblotting from the first time point at day 14 p.i. IgM immunodominant bands of 220, 85, 62 and 40kDa were observed in the 3 infected animals and from CFT-positive CCPP field sera. Band intensity gradually diminished throughout the experiment. IgG immunodominant bands of 108, 70, 62, 44, 40 and 23kDa were shared between experimentally-infected and field sera, with band intensity either remaining unchanged or increasing from day 14 p.i. These bands were not present using pre-infection sera. Of the diagnostic tests used, only the CPS antibody detection latex agglutination test and IgG immunoblotting gave positive diagnoses throughout the entire period post-infection (days 14-53 p.i.).     

Antibody reactivity to Cryptosporidium parvum in saliva of calves after experimental infection

Antibodies against Cryptosporidium parvum in the saliva and sera of three calves experimentally infected with this parasite were examined by an indirect immunofluorescence antibody test and immunoblotting. Salivary anti-C. parvum IgA antibody appeared on day 12 post-challenge and had a tendency to increase transiently between days 15 and 30 post-challenge. Salivary anti-C. parvum IgG antibody levels showed a gradual increase along with the change in IgA antibody levels during the infection. In contrast, serum anti-C. parvum IgA antibody levels showed only a slight increase between days 15 and 30 post-challenge. Serum anti-C. parvum IgG antibody levels rose on day 12 post-challenge and one calf maintained relatively high level up to the end of the experiment. In immunoblotting, an antigen with a molecular mass of 15 kDa was found to react strongly to salivary IgA antibody and a 27 kDa antigen to react to serum IgG antibody.     

上杭县动物疫病免疫抗体检测与分析

为全面掌握上杭县高致病性禽流感、口蹄疫、猪瘟、高致病猪蓝耳病、鸡新城疫等主要动物疫病的免疫效果,根据上级主管部门动物疫病检测方案,对上杭县21个乡镇的1 019份畜禽血清进行了抗体检测,结果显示主要动物疫病免疫抗体合格率均超过农业部规定的标准,表明上杭县2013年秋防主要动物疫病免疫效果总体良好。     

The relationship between the magnitude of the specific antibody response to experimental salmonella enteritidis infection in laying hens and their production of contaminated eggs.

Detecting infected laying flocks is a vital part of many efforts to control egg-associated transmission of Salmonella enteritidis to humans. The relationship between the development of a specific antibody response in infected hens and the deposition of S. enteritidis in eggs is important for establishing the epidemiologic relevance of serologic testing methods. In two trials, laying hens were infected with large oral doses of phage types 13a and 14b isolates of S. enteritidis. Approximately 38% of all infected hens produced at least one contaminated egg, at an overall incidence of 5.2%, between 3 and 23 days postinoculation. As determined by enzyme-linked immunosorbent assay with an S. enteritidis flagellar antigen, 91.7% of inoculated hens produced specific serum antibodies. Although hens with very high antibody titers were associated with a significantly elevated frequency of egg contamination, a consistently direct relationship was not evident between the magnitude of the antibody responses of individual hens and the frequency at which they laid contaminated eggs. Accordingly, although serologic tests can be valuable screening tools for preliminary detection of S. enteritidis infections in poultry, the magnitude of the antibody responses detected in individual hens may not predict the overall risk of egg contamination associated with particular laying flocks.     

怀孕后期感染PRRS病毒母猪所产新生仔猪的免疫反应

将PRRS病毒BJ－4株感染怀孕后期（约90天）的抗体阴性和阳性母猪，待自然分娩后，观察新生仔猪的免疫应答。结果显示，接种PRRS病毒BJ－4的母猪没有表现出明显的临床症状，没有出现流产死产。新生仔猪浦被子前血清中PRRS病毒核酸TR－PCR检测和ELISA抗体阴性，哺乳后特异性抗体出现，5－6周母源抗体逐渐下降；20日龄猪瘟疫苗免疫后疫苗抗体维持时间短，仔猪在40日龄后进入野毒感染的危险期。RT－nested PCR检测血清中PRRS病毒核酸和易感仔猪病毒特异性抗体监测的结果提示仔猪群内可能存在水平传播。流式细胞术检测外周血淋巴细胞亚群发现CD3^ 细胞减少，CD4^ 细胞显著下降，CD8^ ，CD4^ CD8^ 和SLA－DR^ 表达细胞升高。以上结果表明在感染后病毒能够长期持续性存在，猪场内新生仔猪母源抗体逐渐下降后，通过水平传播受到感染，感染后免疫应答受到不利影响。     

Bluetongue virus serotype 20 infection in pregnant Merino sheep

Eleven maiden Merino ewes, free of antibody to bluetongue virus serotype 20 (BTV-20) in agar gel immunodiffusion and serum neutralisation tests, were mated once with a ram. Ten ewes were inoculated with BTV-20 35 to 42 days after service, and one ewe was left as an uninoculated control. One of the inoculated ewes and the control ewe remained uninfected throughout the experiment. Eight of the remaining 9 ewes showed clinical signs ranging from mild to moderate, and the other showed no clinical signs of infection. BTV-20 viraemia was detected in ewes between days 3 and 11 post inoculation, and the serum antibody response was followed. The control ewe and 5 of the 9 infected ewes were pregnant when examined 90 to 97 days after service. Each of these animals produced a normal lamb. There was no evidence of abortion in the remaining 5 ewes, and no transplacental transfer of virus was detected in the lambs of the 5 infected ewes. At necropsy, 46 days after the birth of the last lamb, no gross or microscopic lesions were observed in either the ewes or lambs.     

Analysis of the kinetics, isotype and specificity of serum and coproantibody in lambs infected with Cryptosporidium parvum

Enteric cryptosporidiosis was studied in colostrum-deprived lambs each infected at five days old with 10(6) oocysts. The prepatent period was three to five days and faecal oocyst concentration fell below detectable levels by day 16 after infection. Specific IgA, the only isotype detected by immunofluorescent assay in faecal extracts from infected lambs, was first evident on day 10 and titres continued to rise until day 16 of infection in association with declining oocyst output. Specific IgM and IgG antibodies were first detected in serum seven days after infection. No specific antibody was detected in uninfected control lambs. Immunoblotting methods showed that serum antibody and faecal IgA had similar profiles of antigen recognition. Antigens with approximate molecular weights of 180,000, 23,000 and 15,000 were consistent features on immunoblots performed with convalescent sera and faecal extracts. The results suggest that specific IgA in intestinal secretions has an important role in immunity to cryptosporidiosis.     

Akabane virus infection in the pregnant ewe. 1. Growth of virus in the foetus and the development of the foetal immune response

Three different pools of the CSIRO 16 strain of Akabane virus differing in their laboratory passage histories were used to inoculate 39 ewes between 32 and 36 days pregnant; 22 pregnant ewes received inocula containing no virus. There was no difference in the development, duration and titre of the viraemia and neutralising antibody response between the three infected groups of ewes. Both infected and control ewes had 141% foetuses when autopsied at 69 to 105 days gestation. Of the 55 foetuses from infected ewes 44 (80%) had gross developmental abnormalities.At autopsy of the dams Akabane virus was isolated only from the uterine caruncle. From foetal samples virus was isolated from a wide range of tissues, from one foetus at 69 days and from the blood of four foetuses at 95 to 106 days gestation. Virus was also isolated from 24 of the choriolllantoic fluid samples and from 37 placentomes of the 44 foetuses with developmental defects, in concentrations ranging from 10² to 10^5.5 TCID₅₀/ml or/g. No virus was isolated from the tissues of the control ewes or their foetuses.Neutralising antibody to Akabane virus was detected in 78% of the foetal sera from the infected group, titres ranging from 2 to 64. IgM and IgG₁ and neutralising antibody were detected in sera of 40 foetuses with developmental abnormalities including three that were of 76 to 78 days gestation. Neutralising antibody was detected only in serum that contained IgG₁ but may also have been associated with IgM in infected foetuses. IgM was detected in the serum of most foetuses including the non-infected controls, but sera from the control foetuses did not contain IgG₁ or neutralising antibody to Akabane virus. No IgG₂ or IgA were detected in any foetal serum.     

免疫鸡群发生新城疫的诊断

为了对某新城疫免疫鸡群发生的疫病进行准确诊断,根据流行病学调查、临床症状、病理变化和抗体监测作出初步诊断后,采集病料通过细菌学和RT-PCR进行病原检测,确诊为新城疫强毒感染。