1株肠炎沙门氏菌噬菌体的污水分离及生物学特性研究

Using double-layer plate method, a phage against Salmonella enteritidis was isolated from sewage water, and its biological characteristics were studied. The plaques of isolated phage were transparent with clear boundary, and were about 2 mm in diameter at 12 h. The morphological properties of phage were examined by electron microscope, and showed that the phage had an isometric polyhedral no-enveloped head with diameter of about 54 nm, and a long noncontractile tail with size of about 110 nm. The test of optimal multiplicity of infection showed when MOI equaled 2, the number of phage offspring was higher. One-step growth kinetics was determined according to the results of one-step growth experiment, which showed that the latent period was about 10 min, the rise period was about 100 min, and the average bust size was about 61. The phage against S.enteritidis was successfully isolated from the sewage water in this study, which would provide materials for the further biological control researches of S.enteritidis using corresponding phage.     

2株猪繁殖与呼吸综合征病毒的分离、鉴定及遗传进化分析

Two strains of porcine reproductive and respiratory syndrome viruses (PRRSV) were isolated from serum of some pig farms in Guangdong province and showed PRRSV positive in RT-PCR testing. The two viruses could passage stably and cause typical cenotaphic effect, they were named as LZ-GD and LB-GD. The analysis of variable region sequences of ORF5 and Nsp2 of the two viruses showed that LZ-GD and LB-GD strains were far to Europe strain Lelystad, the homology of nuclear nucleotide sequence were 63.5% and 63.8%, respectively, with classic American strain VR-2332 were 88.7% and 89.1%, respectively, and that with highly pathogenic JXA-1 strain were 99.2% and 99.3%, respectively. There were 30 amino acids deletion in Nsp2. It shared the deletion with JXA-1, HUN4 and other pathogenic variant. Thus, the two strains of PRRSV belonged to highly pathogenic American type.     

香味剂中大茴香脑、d-柠檬烯、香芹酚含量测定的研究

本研究建立了气相色谱法测定饲料香味剂中大茴香脑、d-柠檬烯、香芹酚的方法。试样经丙酮提取后,用GC测定大茴香脑、d-柠檬烯和香芹酚。大茴香脑、d-柠檬烯和香芹酚的线性范围为1.0～500.0μg/mL。大茴香脑、d-柠檬烯和香芹酚在浓度为1～10 g/kg添加水平时的回收率分别在96.2%～101.5%、97.1%～102.5%和96.5%～99.8%,RSD分别为1.3%、1.5%和1.1%。方法定量限为50 mg/kg。本方法对饲料香味剂中大茴香脑、d-柠檬烯和香芹酚的检测分析准确性高、重现性好。     

金山区动物疫病防控体系现状及风险分析

2013年金山区经历了黄浦江死猪漂浮事件和H7N9禽流感疫情,暴露出当前金山区动物疫病防控体系在应对突发公共卫生事件中存在的一些问题,也给金山区疫病防控体系建设提出了新的挑战。本文分析了金山区动物疫病防控体系现状、存在问题,及在应对公共卫生安全事件中可能存在的风险,并提出了切合实际的防控对策,为建立科学的动物疫病防控长效机制提供借鉴。     

天坛株痘苗病毒基因缺失弱毒株的构建及鉴定

本研究旨在通过敲除部分与天坛株痘苗病毒(vaccinia virus Tiantan strain,VTT)毒力和宿主范围等相关的复制非必需基因,并结合双标记筛选及外源筛选标记敲除技术,构建多基因缺失VTT弱毒株。人工合成7对重组臂,结合痘病毒早晚期复合强启动子pE/L和外源筛选标记增强型绿色荧光蛋白(Enhance green fluorescent protein,EGFP),构建穿梭载体质粒pTC-EGFP、pTA35-EGFP、pTA66-EGFP、pTE-EGFP、pTB-EGFP、pTI-EGFP和pTJ-EGFP。将上述质粒依次与VTT或基因缺失VTT共转/感染BHK细胞,并通过同源重组和荧光蚀斑筛选方法,逐一敲除拟缺失基因片段(TC:TC7L^TK2L;TA35:TA35L;TA66:TA66R;TE:TE3L;TB:TB13RTK2L;TA35:TA35L;TA66:TA66R;TE:TE3L;TB:TB13R^TB14R;TI:TI4L;TJ:TJ2R)。利用Cre/Loxp系统实现对外源筛选标记的敲除,最终获得天坛株痘苗病毒基因缺失弱毒株TTVAC7,并运用PCR方法对TTVAC7进行鉴定和遗传稳定性检测。结果表明,本研究成功构建了缺失7个目的片段的天坛株痘苗病毒弱毒株TTVAC7,且该弱毒株具有良好的遗传稳定性。     

驼乳的食疗保健功效

驼乳营养丰富并含有多种生物活性因子和药用成分,具有一定的食疗保健和辅助治疗作用。本文概述了我国少数民族医学对驼乳食疗作用的认知和应用,简要介绍了现代科学在驼乳调节免疫、抗茵抑菌以及辅助治疗消化道疾病、糖尿病、肾病、肿瘤等方面所进行的实验研究。     

空肠弯曲杆菌生物学特性及分型技术研究新进展

Campylobacter jejuni (C.jejuni) is a major pathogen of human campylobacteriosis, as well as one of the major food-borne pathogen. It can not only cause human diarrhea, but also cause many systemic diseases such as endocarditis, arthritis, septisis. The most serious complication it can cause is the Guillain Barre syndrome. In developed countries, C.jejuni even has a trend to excess Salmonella and be reported as next Salmonella, which has caused a worldwide concern. Analysis of biological characteristics for C.jejuni can help us to distinguish it with other pathogens. Typing methods play important roles in the identification, monitoring and prevention of C.jejuni. It can also help us to understand its virulence and resistance mechanisms to C.jejuni. This paper reviews advances of C.jejuni in biological characteristics, serotyping and genotyping methods so as to help us further understand its new progress in these areas.     

芦笋秆提取物对余干乌鸡产蛋性能及血清免疫生化指标的影响

选择产蛋率和体重相近的26周龄余干乌鸡120只,随机分成6个处理,对照组饲喂基础日粮,试验组分别在基础日粮中添加0.5%、0.4%、0.3%、0.2%、0.1%的芦笋秸秆提取物,研究芦笋提取物对产蛋余干乌鸡产蛋性能、免疫性能及血清生化指标的影响。结果表明:添加0.1%~0.5%的芦笋秸秆提取物与对照组相比产蛋率显著提高(P0.05),料蛋比显著降低(P0.05)。添加0.1%~0.4%的芦笋秸秆提取物与对照组相比可显著提高血清中的超氧化物歧化酶和免疫球蛋白G水平(P0.05),在添加0.5%时两者水平皆极显著提高(P0.01)。与对照组相比,添加0.1%~0.5%时,血清中低密度脂蛋白胆固醇和谷丙转氨酶水平极显著降低(P0.01);添加0.1%~0.3%时,血清中的免疫球蛋白M水平显著提高(P0.05),添加0.4%~0.5%时其水平极显著提高(P0.01)。日粮中添加0.1%~0.5%芦笋秸秆提取物有利于提高产蛋期余干乌鸡产蛋率和免疫功能,并具有降低低密度脂蛋白胆固醇和护肝功效。