不同地区沙门菌的流行病学调查及肠炎沙门菌SDBL-1分离株的致病性和传播途径探究

发布时间：2018-11-12 16:33

【摘要】：沙门菌能够导致人类的食物中毒,有重要的公共卫生学意义。本研究首先对部分地区不同品种鸡群采集样品分离沙门菌,从病原学和血清学两方面对流行病学进行了调查;其次选择1株有代表性的肠炎沙门菌SDBL-1分离株对其生物学特性进行探究,最后用肠炎沙门菌SDBL-1分离株对SPF鸡进行感染。初步探讨了SDBL-1分离株对SPF鸡的感染途径及其致病性。为防控肠炎沙门菌的传播奠定了科学基础。不同沙门菌抗体诊断抗原及不同诊断方法对沙门菌抗体测定结果比较试验随机选取210份样品,其中血清样品154份,卵黄样品56份,用某公司4个批次的鸡白痢、鸡伤寒多价染色抗原以玻片凝集法测定鸡白痢、鸡伤寒抗体,比较同一厂家不同批次诊断抗原对其测定结果的差异;随机选择36份血清样品,选择一种商品化的鸡白痢、鸡伤寒多价染色抗原和实验室自制的肠炎沙门菌诊断抗原以玻片凝集法测定抗体;随机选择91份血清样品,用实验室自制的肠炎沙门菌诊断抗原和国产、进口的沙门菌抗体ELISA试剂盒测定抗体,比较结果差异性。试验结果表明,4个批次的鸡白痢、鸡伤寒多价染色抗原血清抗体测定吻合率在65.6%~89.6%之间,卵黄抗体测定的吻合率在98.2%~100%之间,商品化的诊断抗原与实验室自制诊断抗原的吻合率为61.1%,实验室自制抗原与国产及进口的沙门菌抗体ELISA试剂盒吻合率均为69.2%。结果提示,不同诊断抗原及不同的诊断方法之间测定结果存在差异,各种方法之间不能完全代替。不同品种鸡沙门菌的流行病学调查试验选取不同地区8个鸡群,共计2971份血清样品,用抗原抗体平板凝集试验测定沙门菌抗体。选取17个鸡群,采集20胚龄的鸡胚、脏器等样品共计1658份,采用自行优化的沙门菌分离方法,分离鉴定沙门菌。检测结果表明,2971份血清样品中鸡白痢、鸡伤寒阳性率为31.8%,不同鸡群鸡白痢、鸡伤寒血清阳性率在6.2%~71.9%之间。1658份鸡胚及脏器样品中阳性样品为80份,17个鸡群中阳性鸡群有8个,不同鸡群的阳性率在0%~31.5%之间。结果提示,所检测鸡群存在着沙门菌的感染。肠炎沙门菌SDBL-1分离株的致病性及传播途径探究试验选取肠炎沙门菌SDBL-1分离株探究其生物学特性,包括其生长曲线、药物敏感、毒力。以肠炎沙门菌SDBL-1分离株人工感染6周龄SPF鸡(感染组),同时设立空气传播组和对照组,在感染后不同时间同时测定3组试验鸡的体重、血液常规指标、淋巴细胞亚群指标及抗体变化和感染鸡的排毒规律,并检测环境(饲料、饮水、蚊蝇等)中的沙门菌。结果表明,肠炎沙门菌SDBL-1分离株的LD50为1.905×109CFU,其对青霉素g、苯唑西林、卡那霉素、红霉素、麦迪霉素、呋喃妥因、万古霉素、克拉霉素、克林霉素敏感;肠炎沙门菌SDBL-1分离株感染SPF鸡对其体重没有显著影响(P0.05),但其淋巴细胞比率在2、4、6、8d时显著下降,粒细胞比率、粒细胞数量在2、4、6、8d时以及中间细胞比率在4、6、8d时显著上升;感染肠炎沙门菌SDBL-1分离株引起淋巴细胞亚群CD4+、CD8+比例分别在2d、4d先出现下降,在感染后的6d时达到最低,之后逐渐上升恢复平稳,空气传播组有相同趋势,但发生的时间推迟2d。而且,感染组及空气传播组在感染后的4d均检测到抗体。结果提示,肠炎沙门菌SDBL-1分离株感染SPF鸡后,会引起机体炎症反应,造成免疫功能紊乱,引起器官不同程度损伤,沙门菌可通过空气传播,感染鸡可通过粪便、口腔、泄殖腔间歇排毒。综上所述,对于沙门菌的诊断,不同诊断抗原及不同诊断方法之间存在差异;不同地区鸡群存在着沙门菌感染,主要以肠炎沙门菌为主;肠炎沙门菌SDBL-1会引起SPF鸡感染,感染鸡机体受到损伤,并且继续向外界排出细菌,引起环境和鸡群感染。
[Abstract]:Salmonella can cause food poisoning in humans and has important public health significance. In this study, the samples were collected from different breeds of chicken in some regions, and the epidemiology was investigated from the aspects of etiology and serology, and the biological characteristics of Salmonella enteritidis SDBL-1 were selected. The SPF chickens were infected with Salmonella enteritidis SDBL-1. The infection and pathogenicity of SDBL-1 isolates to SPF chickens were discussed. and lays a scientific foundation for preventing and controlling the spread of Salmonella enteritidis. A total of 210 samples were randomly selected from the test results of the different Salmonella antibody diagnostic antigen and the different diagnostic methods. The serum samples were 154 samples, the yolk samples were 56 samples, and four lots of chicken white diarrhea were used. the difference of the test results of the chicken white diarrhea and the chicken typhoid antibody is determined by a slide agglutination method by the chicken typhoid polyvalent staining antigen, 36 serum samples are randomly selected, a commercial chicken white diarrhea is selected, the antibody is detected by a slide agglutination method by a chicken typhoid multivalent stain antigen and a laboratory self-made Salmonella enteritidis diagnostic antigen; 91 serum samples are randomly selected, and an antibody is determined by using a laboratory self-made Salmonella enteritidis diagnostic antigen and a domestic and imported Salmonella antibody ELISA kit, and the difference of the results is compared. The results of the test showed that the matching rate of the antibody was 60.6% ~ 88.9%, the matching rate of the yolk antibody was 98.2% ~ 89. 6%, the coincidence rate of the commercial diagnostic antigen and the self-made diagnostic antigen of the laboratory was 61.1%. The coincidence rate between the self-made antigen of the laboratory and the domestic and imported Salmonella antibody ELISA kits was 69.2%. The results suggested that there was a difference in the results between the different diagnostic antigens and the different diagnostic methods, and the different methods could not be replaced completely. A total of 2971 serum samples from different regions were selected according to the epidemiological investigation of Salmonella in different regions, and the antibody of Salmonella was determined by the antigen-antibody plate agglutination test. A total of 1658 samples of 20-embryo-age chicken embryos and organs were collected, and the Salmonella were isolated and identified by self-optimized isolation method. The results showed that the positive rate of chicken white diarrhea and chicken typhoid in 2971 serum samples was 31. 8%, and the positive rate of chicken's white diarrhea and chicken typhoid in different chicken group was between 6.2% and 71.9%. The positive samples in 1658 chicken embryo and organ samples were 80, and there were 8 positive chickens in 17 chickens. The positive rate of different chicken groups was between 0% and 31.5%. The results suggested that there was a Salmonella infection in the detected chicken group. The pathogenicity and the transmission route of Salmonella enteritidis SDBL-1 isolate were investigated. The biological characteristics of Salmonella enteritidis SDBL-1 were studied, including its growth curve, drug sensitivity and virulence. A 6-week-old SPF chicken (infected group) was infected with Salmonella enteritidis SDBL-1, and the air-spreading group and the control group were set up, and the body weight, blood routine index, lymphocyte subgroup index and antibody change and the toxin-expelling rule of the infected chicken were measured at different time after infection. and the salmonella in the environment (feed, drinking water, mosquito and fly, etc.) is detected. The results showed that the LD50 of Salmonella enteritidis SDBL-1 isolate was 1. 905-109CFU, which was sensitive to penicillins g, penethamate, kanamycin, erythromycin, clindamycin, psoralen, vancomycin, clarithromycin and klincomycin. There was no significant effect on the body weight of the isolated strains of Salmonella enteritidis SDBL-1 (P0.05), but the lymphocyte ratio decreased significantly in 2, 4, 6, and 8 days, and the ratio of the granulocytes and the number of granulocytes in 2, 4, 6, and 8d and the intermediate cell ratio increased significantly at 4,6,8days. The proportion of CD4 + and CD8 + in the subpopulations of the lymphocyte subpopulations in the Salmonella enteritidis SDBL-1 isolates was decreased in the 2d and 4d, respectively. After the infection, the level of CD4 + and CD8 + reached the lowest after the infection, and then the recovery was stable. The air-spreading group had the same trend, but the time of the occurrence was delayed by 2d. In addition, the infection group and the air distribution group all detected the antibody after the infection. The results suggest that the Salmonella enteritidis SDBL-1 isolate can cause the inflammation of the body, cause the immune function disorder, cause the organ to different degree damage, the salmonella can spread through the air, the infected chicken can pass through the stool, the oral cavity and the cloaca chamber for intermittent detoxification. To sum up, there is a difference between different diagnostic antigens and different diagnostic methods for the diagnosis of Salmonella, and there are Salmonella infections in different regions of the chicken group, mainly in the form of Salmonella enteritidis; the Salmonella enteritidis SDBL-1 can cause the SPF chicken to be infected, and the infected chicken body is damaged, and continue to discharge the bacteria to the outside, causing the environment and the chicken population to be infected.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S858.31

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