延平区两猪场伪狂犬血清检测及垂直感染风险评估

发布时间：2018-06-23 23:45

本文选题：猪伪狂犬病 + gE-ELISA　；参考：《福建农林大学》2015年硕士论文

【摘要】：目的：利用gE-ELISA和gB-ELISA试剂盒评估分析福建省南平市延平区两个规模化猪场的猪伪狂犬野毒感染率,并建立PCR诊断方法对两猪场猪伪狂犬野毒的垂直传播风险进行分析。方法：对2014年11月～12月份南平市延平区两个规模化猪场进行猪伪狂犬gE抗体及gB抗体检测,并对结果进行统计分析,评估两个规模化猪场的野毒感染阳性率。将统计结果与2013年南平市延平区流行病疫情调查结果进行对比分析,以评估2014年这两个猪场猪伪狂犬病毒(PRV)的流行进展。基于gE基因建立检测猪伪狂犬(PR)野毒的PCR诊断方法,并分析建立的PCR方法的特异性、灵敏性、重复性以及与国家标准的相符性。使用本试验建立的PCR方法检测两规模化猪场和延平区12个猪场的gE抗体阳性猪群的脐带血以及公猪精液,统计对比两猪场脐带血和精液的PCR阳性检出率与12个猪场的平均阳性率,评估两规模化猪场的垂直传播风险压力。结果与分析：A猪场共抽样353份血清,B猪场共抽样267份血清,gE抗体检测结果表明,A、B两场所检测的猪群中除公猪外,其他所有猪群均检出gE抗体,总阳性率分别为：51.08%、58.80%,说明了两场均是PR野毒的阳性场。两场公猪的gE抗体阳性率为0.00%,属于阴性猪群,说明了公猪群未被PR野毒感染。A、B猪场的母猪gE抗体阳性率分别为：53.87%、46.15%；30～40日龄保育猪的gE抗体阳性率分别为：26.09%、51.16%,加上可疑数的比例后分别为：31.89%、51.16%；60日龄保育猪的gE抗体阳性率分别为：45.45%、65.96%；而90～120日龄猪群gE抗体阳性率高达90%以上,由此推断在转舍(保育舍转至肥育舍)时该阶段猪群被PR野毒感染。gB抗体检测结果表明：两场的gB总抗体阳性率分别为96.87%、96.84%；两个猪场公猪的gB抗体阳性率都为100.00%；母猪的gB抗体阳性率分别为93.4%、100.00%,抗体水平高且离散度低,有可能是疫苗免疫和PR野毒感染的综合作用；30-40日龄保育猪的gB抗体阳性率分别为94.20%、97.67%,且整齐度高,因此可推断除了受母源抗体的影响,两猪场的首免效果好,而抗体水平A猪场高于B猪场；两猪场60日龄至120日龄仔猪血清的gB抗体S/N值持续降低,即抗体水平升高,而此阶段母源抗体已几乎消退,gE抗体也不降反升,因此推断60日龄尤其是120日龄转舍时猪群受野毒感染。2014年A场gE抗体阳性率平均值为51.08%,B场gE抗体阳性率平均值为58.80%,与2013年延平区20个猪场的猪伪狂犬病野毒感染调查结果56.26%相比,无下降,而从临床上调查A、B两场无爆发病情,说明两猪场猪群呈隐性感染,虽然2014年A、B两场PR的得到了有效的控制,但隐形感染和种猪排毒现象较为严重,需制定有效的免疫程序,加强疫苗免疫,提高猪场的养殖条件。在本研究中,我们基于gE基因片段,建立的猪伪狂犬病PCR诊断方法具有良好的特异性,灵敏性和重复性。对野毒、疫苗毒以及阴性病料的检测结果,与国标一致。利用这一方法,我们抽检了延平区12个猪场和A、B两场的脐带血和公猪精液。检测结果如下：延平区12个猪场共抽检132份脐带血,PCR阳性率为31.82%,A场阳性率为57.14%,B场阳性率为60.71%；12个场共抽检公猪精液86份,阳性率为15.12%,A、B两场公猪精液PCR野毒阳性率均为0.00%,由此推断A、B两猪场由母猪传播给仔猪的垂直感染压力大,高于延平区12个猪场的平均水平,而由公猪精液传播的暂未造成危险。由两猪场的gE以及gB抗体检测结果分析表明,两个猪场猪群除公猪外都呈隐性感染,临床无症状,可见猪群得到有效控制,生产较为稳定,但由保育猪舍转至肥育猪舍时,gE抗体明显升高,此阶段仔猪母源抗体已消退,加上环境突变等因素,猪群由于应激而容易被野毒感染,加上母猪排毒,使得病毒在场内循环,因此对仔猪首免及肥育猪监测是稳定gE抗体阳性的关键。结论：虽然通过疫苗接种有效减少猪伪狂犬病的发生的散播,但大部分猪场并没有彻底消灭猪伪狂犬病,部分免疫猪仍有排毒的可能,严重威胁易感猪。因此两猪场需要对母猪进行严格的免疫防控,尽可能淘汰阳性猪以免给猪场造成生产繁殖压力,保障新生仔猪的品质。用ELISA检测方法对猪场的不同猪群的PRV-gB抗体和PRV-gE抗体进行血清学检测,并对其结果进行评估,以作为判断该猪场是否感染野毒、接种疫苗是否达到最佳效果的依据,并结合PCR诊断方法分析评估被检猪群的垂直传播风险,对指导规模化猪场全面实施伪狂犬病净化是有实际意义的。
[Abstract]:Objective: To evaluate and analyze the wild virus infection rate of porcine pseudorabies in two large-scale pig farms in Yanping District, Nanping, Fujian Province, and to establish a PCR diagnosis method to analyze the vertical transmission risk of wild poison in two pig pseudorabies by using the gE-ELISA and gB-ELISA kit. Method: two large-scale pig farms in Yanping District of Nanping city from November 2014 to December were entered. The gE antibody and gB antibody of the pig pseudorabies were detected and the results were statistically analyzed to evaluate the positive rate of wild virus infection in two large-scale pig farms. The statistical results were compared with the epidemiological survey results of the Nanping Yanping District in 2013 to evaluate the epidemic progress of the porcine pseudorabies virus (PRV) in the two pig farms in 2014. To establish a PCR diagnostic method for detection of wild poison in porcine pseudorabies (PR), and to analyze the specificity, sensitivity, repeatability and compliance with the national standard of the established PCR method. The PCR method established in this experiment was used to detect the umbilical cord blood and boar semen of the gE antibody positive pigs of two large-scale pig farms and 12 pig farms in Yanping District. The statistical comparison of two pigs was made. The PCR positive rate of field umbilical cord blood and semen and the average positive rate of 12 pig farms were used to assess the vertical transmission risk pressure in two large-scale pig farms. Results and analysis: a total of 353 serum samples were sampled from the A pig farm, and 267 serum samples were sampled from B piggery. The results of gE antibody test showed that all pigs in the pigs tested by A and B were examined in addition to the boars except for the boars. The positive rates of gE antibody were 51.08% and 58.80%, respectively. The positive rate of two fields was PR wild. The positive rate of gE antibody of two boars was 0%, which belonged to negative pigs. It showed that the boar group was not infected with PR and.A, and the positive rate of gE antibody of sow in B pig farm was 53.87%, 46.15%, and the positive rate of gE antibody in 30~40 day old pigs was divided. 26.09%, 51.16%, plus the proportion of suspicious numbers, respectively: 31.89%, 51.16%; the positive rates of gE antibody in 60 day old pigs were 45.45%, 65.96%, while the positive rate of gE antibody in the 90~120 days old pigs was up to 90%. Thus, it was concluded that the pig group was detected by PR wild venom.GB antibody at this stage when the transfer house was transferred to the fattening house. The results showed that the positive rate of gB antibody in two fields was 96.87%, 96.84%, and the positive rate of gB antibody in two pig farms was 100%, and the positive rate of gB antibody of sow was 93.4%, 100%, the level of antibody was high and the degree of dispersion was low. It may be a comprehensive cooperative use of vaccine immunization and PR wild virus infection, and the positive rate of gB antibody in 30-40 day old pigs. 94.20%, 97.67%, and high degree of uniformity, therefore, it can be concluded that in addition to the influence of mother antibody, the first immunization effect of two pig farms is good, and the antibody level A pig farm is higher than the B pig farm; the serum gB antibody S/N value of the two pig farm from 60 days to 120 days old decreases continuously, that is, the antibody level rises, and the maternal antibody has almost subsided, and the gE antibody also does not It was concluded that the average value of gE antibody positive rate in.2014 year A field of pig group at 60 days old, especially 120 days old, was 51.08%, and the average value of gE antibody positive rate of B field was 58.80%, compared with the result 56.26% of swine pseudorabies wild virus infection in 20 pig farms in Yanping area in 2013, no descent, but from clinical investigation A, B two fields were not exploded. It shows that the two pig farms are recessive infection in the two pig farm. Although the two fields of PR in 2014 and B have been effectively controlled, the stealth infection and the porcine detoxification are more serious. It is necessary to formulate effective immune procedures, strengthen the immunization of the vaccine and improve the breeding conditions of the pig farms. In this study, we based on the gE gene fragment to establish the PCR diagnosis of porcine pseudorabies. The method had good specificity, sensitivity and repeatability. The results of detection of wild, vaccine and negative diseases were the same as the national standard. Using this method, we checked the umbilical cord blood and boar semen of 12 pig farms and A and B fields in Yanping District. The results were as follows: 132 umbilical cord blood samples were sampled from 12 pig farms in Yanping District, and the positive rate of PCR was detected. For 31.82%, the positive rate of A field was 57.14%, the positive rate of B field was 60.71%, and 86 parts of the boar semen were detected in 12 fields, the positive rate was 15.12%, A, and the positive rate of PCR wild poison in the semen of the two boars was 0%. Thus, A was infer that the vertical infection pressure of the piglets transmitted by the sows in the B two pig was higher than the average level of the 12 pig farms in the Yanping District, and the semen passed from the boar semen. The analysis of the gE and gB antibody test results from two piggery showed that the two pig farms were infected with recessive infection except for the boars, and the clinical symptoms were asymptomatic. The pigs were effectively controlled and the production was more stable, but the anti body body of the piglets increased obviously when the pig houses were transferred to the fattening piggery, and the antibody of the mother source of the piglets had subsided at this stage. Because of the environmental mutation and so on, the pig group is easily infected by the wild virus because of stress, and the sow detoxification, causing the virus to circulate in the field. So the monitoring of the piglet first and the fattening pigs is the key to stabilizing the gE antibody positive. Conclusion: Although the vaccine inoculation effectively reduces the spread of porcine pseudorabies, most pigs are not thoroughly. To eliminate porcine pseudorabies, some pigs still have the possibility of detoxification, which seriously threaten the susceptible pigs. Therefore, the two piggery needs to be strictly immune and control the sows, to eliminate the positive pigs as much as possible so as to avoid the production pressure of the piggery and to ensure the quality of the newborn piglets. The PRV-gB antibody and PRV-gE of different pig farms in the pig farm are used by the ELISA test method. The antibody was tested by serology, and the results were evaluated as a basis for judging whether the pig farm was infected with wild poison and whether the vaccine reached the best effect, and the PCR diagnostic method was used to analyze the vertical transmission risk of the pigs tested. It was of practical significance to guide the purification of Pseudorabies in a large-scale pig farm.
【学位授予单位】：福建农林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.28

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