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克罗诺杆菌是一种新型的食源性致病菌。迄今为止,对阪崎克罗诺杆菌的免疫原和潜在毒力因子了解很少,而免疫原性蛋白在细菌的致病性方面发挥着重要的作用。本研究利用免疫蛋白组学的方法,鉴定了阪崎克罗诺杆菌ATCC 29544的免疫原性蛋白。利用固定后的阪崎克罗诺杆菌ATCC 29544菌体免疫新西兰兔,制备多克隆抗体;采用蔗糖密度梯度离心法,提取蛋白质,并利用双向电泳对蛋白质进行分离;以制备的多克隆抗体作为一抗进行免疫印迹分析,对具有免疫反应的蛋白点进行质谱鉴定,结果共鉴定出7种具有明显免疫反应的蛋白质。 相似文献
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为研究降低蛋清蛋白免疫原性的有效方法,分别采用微波、酶解、微波协同酶解对蛋清蛋白进行处理,采用酶联免疫吸附试验测定蛋清蛋白的免疫原性,并利用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、傅里叶变换红外光谱、荧光光谱及紫外光谱等对蛋清蛋白结构进行表征。结果表明,微波700 W/20 s处理和碱性蛋白酶水解后蛋清蛋白免疫原性分别降低了50.81%和55.83%,而微波协同酶解后免疫原性进一步降低,最高降低了67.48%。经不同方法处理后十二烷基硫酸钠-聚丙烯酰胺凝胶电泳条带均发生变化;荧光光谱分析结果表明,3种方法处理使氨基酸微环境发生改变;利用傅里叶变换红外光谱进一步分析发现,不同方法处理的蛋清蛋白二级结构向无序方向转变,蛋白的二、三级结构均发生改变;此外,蛋清蛋白的表面疏水性均有所升高。说明蛋清蛋白免疫原性降低与不同方法处理改变蛋白质原有的结构特性相关。综上,微波协同酶解更有效地降低了蛋清蛋白致敏性,蛋清蛋白结构的变化与其免疫原性有关。 相似文献
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ABSTRACT: Ricin is a potent protein toxin that could be exploited for bioterrorism. Although ricin may be detoxified using heat, inactivation conditions in foods are not well characterized. Two brands of pulp-free orange juice and 2 brands of single-strength apple juice (one clarified and the other unclarified) containing 100 μg/mL added ricin were heated at 60 to 90 °C for up to 2 h. With increasing heating times and temperatures the heat-treated juices exhibited decreasing detectability of ricin by enzyme-linked immunosorbent assay (ELISA) and cytotoxicity to cultured cells. Z-values for ricin inactivation in orange juices were 14.4 ± 0.8 °C and 17 ± 4 °C using cytotoxicity assays, compared to 13.4 ± 1.5 °C and 14 ± 2 °C determined by ELISA. Although insignificant differences were apparent for z-values measured for the 2 orange juice brands, significant differences were found in the z-values for the 2 brands of apple juice. The z-values for ricin inactivation in the clarified and unclarified apple juices were 21 ± 4 °C and 9.5 ± 1.1 °C, determined by cytotoxicity assays, and 20 ± 2 °C and 11.6 ± 0.7 °C, respectively, using ELISA. Overall, there were no significant differences between results measured with ELISA and cytotoxicity assays. Ricin stability in orange juice and buffer was evaluated at 25 °C. Half-lives of 10 ± 3 d and 4.9 ± 0.4 d, respectively, indicated that active ricin in juice could reach consumers. These results indicate that ricin in apple and orange juices can remain toxic under some processing and product storage conditions. Practical Application: Ricin is a potent toxin that is abundant in castor beans and is present in the castor bean mash by-product after cold-press extraction of castor oil. U.S. Health and Human Services recognizes that ricin could be used for bioterrorism. This study reports the stability of ricin in apple and orange fruit juices at temperatures ranging from 60 to 90 °C (140 to 194 °F). 相似文献
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研究鱼油姜黄提取物的急性毒性和亚急性毒性,为评价其食用安全性提供试验依据.对鱼油姜黄提取物进行大、小鼠急性经口毒性试验和大鼠30d喂养试验.试验结果表明,大、小鼠急性经口MTD值>15000mg/kg·BW,属无毒级;3个剂量组雌、雄大鼠的每周体重、每周进食量、每周食物利用率、总食物利用率、脏体比值、血液学指标及末期血... 相似文献
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赤霉素GA3急性毒性和遗传毒性 总被引:1,自引:0,他引:1
目的:研究赤霉素GA3的急性毒性和遗传毒性,为合理使用赤霉素以及赤霉素残留限量标准的制定提供参考。方法:采用最大剂量耐受法测定赤霉素GA3的急性毒性,采用蚕豆根尖细胞微核实验、小鼠骨髓细胞微核实验和小鼠精子畸形实验测定赤霉素GA3的遗传毒性。结果:给昆明种小鼠经口灌胃赤霉素GA3,LD50>15 000 mg/kg;赤霉素GA3在质量浓度为0.1~2.0 mg/L范围内时,蚕豆根尖细胞微核率呈上升趋势,与阴性对照组相比均存在极显著差异,且微核指数均>1.5;7.5 g/kg赤霉素GA3对雌、雄小鼠的骨髓细胞微核率分别为7.47‰、7.07‰,小鼠精子畸形率为5.47%,与阴性对照组相比均存在极显著差异(P<0.01)。结论:赤霉素GA3的急性毒性虽然比较低,属于无毒级,但是在较高剂量条件下对植物细胞、动物的体细胞与生殖细胞均具有遗传毒性,应尽快制定赤霉素GA3使用限量标准。 相似文献
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目的:对常见的硒强化剂亚硒酸钠的毒性进行研究。方法:以Wistar大鼠为实验动物,分别采用改良寇氏法进行急性毒性实验,剂量递增法进行蓄积毒性实验,以1/20 LD50、1/10 LD50、1/5 LD50剂量连续灌胃30d进行亚急性毒性实验。系统研究亚硒酸钠对大鼠生长状况、组织病理变化、血常规、血液生化指标的影响。结果:大鼠经口灌胃亚硒酸钠的LD50为11.75mg/kg,蓄积系数为3.3,有中等蓄积毒性作用。0.588mg/kg剂量亚硒酸钠对大鼠生长有一定抑制作用,剖检及组织学变化以心、肝、脾、肺、肾等实质器官损伤为主,对主要器官脏器指数、血常规指标、血液生化指标均有不同程度影响。结论:亚硒酸钠属于高毒性物质,可以对大鼠造成急性、蓄积性、亚急性损伤。 相似文献
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灵菌红素属于天然色素,具有离体抑制肿瘤和癌症细胞增殖、抑制微生物生长以及抗疟疾和免疫抑制等功效,具有潜在的巨大应用价值。缺少急性经口毒性和遗传毒性实验的研究限制了灵菌红素在食品工业领域的应用。本研究依据食品安全国家标准进行了灵菌红素的小鼠急性经口毒性实验、哺乳动物红细胞微核实验、小鼠精子畸形实验和细菌回复突变实验。结果表明,灵菌红素急性经口半数致死剂量LD_(50)10 g/kg(以体质量计),3项遗传毒性实验结果为阴性,灵菌红素对小鼠的急性经口毒性属无毒级,对正常细胞无毒,对动物生殖系统没有毒害。 相似文献
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目的:研究家蚕茧壳水解粉的急性毒性和遗传毒性。方法:应用小鼠急性毒性实验、体外哺乳类细胞(V79/HGPRT)基因突变实验、小鼠骨髓细胞染色体畸变实验及小鼠精子畸变实验对家蚕茧壳水解粉毒性进行研究。结果:该家蚕茧壳水解粉对雌雄小鼠半数致死量(median lethal dose,LD50)均大于11.50 g/kg,属实际无毒物质;基因突变实验中各受试物剂量组的突变率均没有达到自发突变率的3 倍,亦无剂量-反应关系,结果为阴性;染色体畸变实验中家蚕茧壳水解粉各剂量组与阴性对照组无显著差异(P>0.05);精子畸变实验中,样品低、中剂量组与阴性对照组无显著差异(P>0.05),而高剂量组畸变率显著低于阴性对照组(P<0.05),证明实验结果均为阴性。结论:本次实验条件下,该家蚕茧壳水解粉属实际无毒级,未显示有急性毒性和遗传毒性作用。 相似文献
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ABSTRACT: Mutagenicity and acute toxicity of 2-dodecylcyclobutanone (2-DCB), a unique radiolytic product, were evaluated. Mutagenicity was evaluated by the Ames assay using 5 standard Salmonella tester strains with S9 enzyme activation and 5 concentrations of 2-DCB. Sodium azide (NaN3 ), fenaminosulf, and2-aminofluorene (2-AF) served as positive controls. The Ames assay showed no difference between the 5 concentrations of 2-DCB and the controls, including samples incubated with S9. The results indicate that 2-DCB does not produce point or frameshift mutations in Salmonella and is not activated by S9. Acute toxicity of 2-DCB was evaluated by the Microtox acute toxicity system and compared with cyclohexanone and 2-nonenal (both GRAS additives). The effective concentrations that caused a 50% reduction in light emission by Vibrio fischeri cells (EC50 ) were; 21.72 6 14.57 ppm for 2-DCB, 37.40 6 0.45 ppm for cyclohexanone, and 1.65 6 0.26 ppm for 2-nonenal. The maximum number of cells affected by 2-DCB was 65% 6 4%, while it reached 90% to 100% for the other 2 compounds. Our results suggest that even though the EC50 for 2-DCB is lower than that for cyclohexanone, it was not toxic enough to decrease light emission of V. fischeri beyond 60% to 70%. These results indicate that the potential risk from 2-DCB, if any, is very low. 相似文献
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通过小鼠急性毒性试验、大鼠急性毒性试验、小鼠嗜多染红细胞微核试验、小鼠精子畸形试验、Ames试验及大鼠30d毒试验来评估蛋黄抗体的安全性.试验结果表明,7d内小鼠和大鼠均未出现明显中毒症状和死亡,3项致突变试验结果也均为阴性.大鼠30d长毒试验中临床检查、血像、生化、脏器组织病理学等项目测定均无异常.结论为IgY无急性毒性和致突变性,属安全制剂. 相似文献