蒙脱石对黄曲霉毒素B1体外吸附效果评估

试验评估蒙脱石对黄曲霉毒素B1(AFB1)的体外吸附效果,探究AFB1浓度、蒙脱石有效含量及添加量、pH值、吸附时间及吸附温度对蒙脱石吸附AFB1的影响.试验制作高(98.8 μg/kg)、低(48.9 μg/kg)两种不同浓度的AFB1污染饲料,将5种不同有效含量的蒙脱石以3种添加量添加到带毒饲料中吸附AFB1,加入...     

黄曲霉毒素B1对肉鸡毒性危害研究进展

黄曲霉毒素B₁(AFB₁)是目前自然界中已知致癌性最强、毒性最大的真菌毒素。AFB₁能够对肉鸡日粮造成污染,从而限制我国肉鸡养殖业的健康发展。现阶段AFB₁对肉鸡毒性危害主要体现为慢性消耗。文章综述了肉鸡的遗传、生理和环境因素对AFB₁毒性的影响以及AFB₁对肉鸡生产性能、免疫系统和组织器官的影响,并对肉鸡生产中常用解毒剂的特点进行总结,为减轻AFB₁对肉鸡的危害提供参考。     

生物降解花生粕中黄曲霉毒素B1的研究

为探讨生物降解黄曲霉毒素的作用,试验采用在花生粕中接种黄曲霉菌,并在30℃环境中培养7 d,使其产生黄曲霉毒素,然后分别采用高温高压法、添加1%乳酸菌和1%酵母菌3种方法处理试样,并测定其黄曲霉毒素B1(AFB1)含量。结果发现,经高温和高压处理可破坏部分AFB1,但仍有72.3%的AFB1存在;经乳酸菌30℃厌氧培养72 h,可使99.4%的AFB1得到破坏;经酵母菌30℃培养72 h可使83.4%的AFB1得到降解,且乳酸菌的处理效果显著优于酵母菌的处理效果。     

白藜芦醇对黄曲霉毒素B1致兔肾脏损伤的保护作用

【目的】探究白藜芦醇(resveratrol, Res)对黄曲霉毒素B₁(aflatoxin B₁,AFB₁)致兔肾脏损伤的保护作用。【方法】将21只40日龄的家兔随机分为3组，每组7只，分别为对照组、AFB₁组和AFB₁+Res组，其中对照组饲喂基础饲粮，AFB₁组饲喂含0.3 mg/kg BW AFB₁的基础饲粮、AFB₁+Res组饲喂含0.3 mg/kg BW AFB₁和30 mg/kg BW Res的基础饲粮，试验期21 d。试验结束后观察家兔肾脏组织病理变化，检测血清中肌酐(creatinine, CRE)、尿素氮(urea nitrogen, BUN)和尿酸(uric acid, UA)含量，检测肾脏组织中谷胱甘肽过氧化物酶(glutathione peroxidase, GSH-Px)、超氧化物歧化酶(superoxide dismutase, SOD)、总抗氧化能力(tota...     

改性水合硅铝酸盐对黄曲霉毒素B1及维生素的体外吸附研究

研究选取改性水合硅铝酸盐及国内外市场上有代表性的几种霉菌毒素吸附剂作为研究对象,通过体外的模拟吸附试验,分析不同霉菌毒素吸附剂对黄曲霉毒素B1及几种维生素的吸附能力.试验结果表明,改性水合硅铝酸盐及其他几种吸附剂对于脂溶性维生素的体外吸附量较少,对水溶性维生素的体外吸附量较大,相比其他几种吸附剂,改性水合硅铝酸盐对脂溶和水溶维生素的体外吸附量都较小.几种吸附剂对黄曲霉毒素的体外吸附都超过97％,且在有营养物质存在的条件下,会选择性地吸附营养物质.     

酶联免疫法检测饲料中黄曲霉毒素B1

黄曲霉毒素B1是危险的致癌物,经常在玉米、花生粕、棉籽粕和菜籽粕等饲料原料中检测到。经试验证明,使用酶联免疫法检测黄曲霉毒素B1灵敏度高,最低检出限为1μg/kg;标准曲线r值≥0.9955,变异系数≤3.5%,检测回收率≥95.02%;此外还具有检测时间短,检测过程约需2h,重复性好,操作过程简单方便,不接触有毒试剂等优点。     

黄曲霉毒素B1残留ELISA试剂盒的研制及应用

本研究采用间接竞争酶联免疫吸附试验(ELISA)检测黄曲霉毒素B₁(aflatoxins B₁,AFB₁)残留量。将AFB₁与蛋白质载体牛血清蛋白(BSA)和卵清白蛋白(OVA)偶联制备了AFB₁-BSA和AFB₁-OVA偶联物,以AFB₁-BSA作为免疫原制备特异性抗体,并成功建立了AFB₁残留间接竞争ELISA检测方法及检测试剂盒。试剂盒IC₅₀为128.8 ng/L,检测线性范围为50~1800 ng/L,检测限不超过100 ng/kg;食用油、花生和谷物的平均添加回收率大于71.3%,批内、批间变异系数均小于14.2%。因此,本试剂盒具有操作简便、检测快速、灵敏度高等特点,将在植物性食品中AFB₁的残留检测中发挥重要作用。     

改性蒙脱石对黄曲霉毒素B1吸附机理的研究

研究了改性蒙脱石对黄曲霉毒素B1的等温吸附,以及赖氨酸、酸碱度、温度、离体肠管吸收及透析袋透析对其吸附的影响。结果表明,改性蒙脱石在pH2.0和pH8.0时对黄曲霉毒素B1的最大吸附量分别为598.8μg/g、682.4μg/g;赖氨酸含量为2.0mg/mL和4.0mg/mL时对吸附无影响;酸碱度在pH2.0至pH8.0及温度在20℃至60℃时对吸附无明显影响;改性蒙脱石可减少离体肠管对黄曲霉毒素B1的吸收率及黄曲霉毒素B1通过透析袋的透析率。改性蒙脱石对黄曲霉毒素B1可能以化学吸附为主;鸡小肠对黄曲霉毒素B1存在主动吸收过程。     

玉米赤霉烯酮、呕吐毒素及黄曲霉毒素B1联合染毒对小鼠睾丸的影响

试验旨在探究玉米赤霉烯酮(ZEN)、呕吐毒素(DON)和黄曲霉毒素B1(AFB₁)联合染毒对小鼠睾丸的毒性作用。选用60只8周龄SPF ICR小鼠,适应性饲养10 d后,将体重相近(38.88±0.29)g的48只小鼠随机分为4组,每组12只,低剂量霉菌毒素联合染毒组(LD组)腹腔注射10mg/kgBWZEN+1 mg/kg BW DON+0.5 mg/kg BW AFB₁,中剂量霉菌毒素联合染毒组(MD组)腹腔注射20 mg/kg BW ZEN+1.5 mg/kg BW DON+1 mg/kg BW AFB₁,高剂量霉菌毒素联合染毒组(HD组)腹腔注射30 mg/kg BW ZEN+2 mg/kg BW DON+2 mg/kg BW AFB₁,对照组(CON组)腹腔注射等量玉米油。腹腔注射24 h后处死小鼠,采集附睾精子及睾丸组织样本。结果表明：与CON组相比,LD组(P<0.05)、MD组(P<0.001)、HD组(P<0.001)精子活性均降低;与CON组相比,霉菌毒素联合染...     

复合生物解毒剂在人工胃肠液中对黄曲霉毒素B1降解率的影响

【目的】试验以人工胃肠液(artificial gastrointestinal fluid, AGIF)作为反应体系,研制高效的霉菌毒素生物解毒剂,以达到有效降解黄曲霉毒素B₁(aflatoxin B₁,AFB₁)的目的。【方法】首先考察4种益生菌在人工胃肠液中对AFB₁的降解率,然后使用响应面设计对4种益生菌组合进行优化,制备复合益生菌;其次,将复合益生菌与不同浓度的AFB₁降解酶进行复合,以筛选最佳复合生物解毒剂;最后评估复合生物解毒剂对AFB₁的降解效果。【结果】(1)枯草芽孢杆菌(Bacillus subtilis)、干酪乳杆菌(Lactobacillus casein)、粪肠球菌(Enterococcus faecalis)和产朊假丝酵母(Candida utilis)在人工胃肠液条件下对AFB₁降解率分别为20.59%、19.97%、28.75%和25.67%;(2)利用响应面设计对4种益生菌进行优化组合,结果表明4种益...     

黄曲霉毒素B1、玉米赤霉烯酮和呕吐毒素的累加细胞毒性研究

由于饲料中多种霉菌毒素并存的几率比较高,本研究以仔猪肠上皮细胞(IPEC-J2)为模型,研究黄曲霉毒素B1(AFB1)、玉米赤霉烯酮(ZEA)和呕吐毒素(DON)的叠加细胞毒性.细胞毒性试验选用AFB1、ZEA和DON三种毒素作为响应面Box-Behnke设计的三个因素,以AFB1:10、20、30μg/L,ZEA:1...     

Effectiveness of maifanite in reducing the detrimental effects of aflatoxin B1 on hematology,aflatoxin B1 residues,and antioxidant enzymes activities of weanling piglets

A feeding trial was conducted to evaluate the effectiveness of maifanite, which is mainly composed of aluminosilicate, in reducing the adverse effects of aflatoxin B₁ (AFB₁) on hematology, AFB₁ residues, and antioxidant enzymes activities in weaning piglets. A total of 32 (9.28±0.17 kg BW) individually housed crossbred piglets (Duroc×Landrace×Large white) were randomly allotted to 1 of 4 dietary treatments in a 2×2 factorial arrangement with 8 replicates per treatment. The dietary treatments included 2 AFB₁ levels (5.3 and 372.8 μg/kg) and 2 maifanite levels (0% and 1%). No differences in average daily gain, average daily feed intake, and gain to feed ratio were observed among treatments. Ingestion of the AFB₁-contaminated (AF) diets (372.8 μg/kg of AFB₁) reduced (P<0.05) the numbers of neutrophil, monocyte, and total leukocyte. There were no effects of AFB₁ on gamma glutamyltransferase, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase activities, and total protein, albumin, urea N, total bilirubin, IgG, IgA, and IgM concentrations in serum. Aflatoxin B₁ was found in the liver and kidney of piglets fed the AF diets. Piglets fed the AF diets reduced (P<0.05) the total superoxide dismutase, glutathione peroxidase, and catalase activities in serum. However, total superoxide dismutase activity in the liver was increased (P<0.05) in piglets fed the AF diets compared with those fed the basal diets (5.3 μg/kg of AFB₁). There was an interaction (P=0.003) in erythrocyte, but piglets fed the diets containing maifanite had greater erythrocyte and lymphocyte (P=0.035) numbers than those fed the diets without maifanite. The AFB₁ levels in the liver and kidney of piglets fed the AF diet containing maifanite were 29.6% and 41.2% lower, respectively, than those of piglets fed the AF diet alone. Although there was an interaction (P=0.011), piglets fed the diets containing AFB₁ and maifanite had greater serum T-SOD activity compared with those fed the diets with no maifanite. In conclusion, the addition of maifanite to the AF diet resulted in partial restoration of hematology and antioxidant enzymes activities and reduced AFB₁ levels in the liver and kidney.     

Pathological lesions following an experimental intoxication with aflatoxin B1 in broiler chickens

A follow-up of chickens dosed orally over 21 days with 0.2 and 3 micrograms of aflatoxin B1 (AFB1) g-1 of bodyweight daily and their subsequent recovery 10 days after withdrawal of contaminated food was conducted. Vacuolation of liver cells during the initial days of the intoxication and cellular depletion in the follicle medulla of the bursa of Fabricius were the lesions which appeared first and persisted during the recovery phase in both groups of intoxicated animals. The intensity of these lesions and their persistence was related to the dose of aflatoxin ingested. A significant reduction in the bodyweight and absolute weights of liver, bursa of Fabricius spleen and thyroid was observed in the higher dose group.     

鸡新城疫病毒B95株的RT—PCR检测方法研究

本试验设计了一对B95株的特异引物NDV－P1／P2，探讨了对其进行RT－PCR检测的可行性，结果证明，用该引物可以扩增出一条310bp的特异核酸带，敏感性为0．0043ng/ul。     

Changes in growth performance, digestive enzyme activities and nutrient digestibility of cherry valley ducks in response to aflatoxin B1 levels

The objective of this study was to investigate toxic effects of aflatoxin B1(AFB₁) on growth performance, organs, hepatic enzyme activities, apparent digestibility of nutrients and digestive enzyme activities in ducks. Ninety 1-day-old Cherry Valley commercial ducks were designed to three treatment groups with three replicates of ten birds each. Group I (control) was fed conventional feed free of AFB₁, group II or III was fed the diets containing 20 μg/kg or 40 μg/kg AFB₁-contaminated rice respectively. The feeding trial lasted 6 weeks. The results were that decreased body weight gain and feed intake, increased feed to gain ratio and selected organ weights (liver, kidney and pancreas) were observed in AFB₁-treated groups. The activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were significantly increased in AFB₁-contamined groups. The apparent digestibility of crude protein (CP) was significantly lower while activities of digestive enzyme from duodenum contents including protease, chymotrypsin, trypsin and amylase were increased in AFB₁-treated group. These results indicated that AFB₁ of feed could decrease growth performance and apparent digestibility of nutrients, change digestive enzyme activities of duodenum contents in duck.     

Aflatoxin B1 in poultry: Toxicology, metabolism and prevention

Aflatoxins (AF) are ubiquitous in corn-based animal feed and causes hepatotoxic and hepatocarcinogenic effects. The most important AF in terms of toxic potency and occurrence is aflatoxin B₁ (AFB₁). Poultry, especially turkeys, are extremely sensitive to the toxic and carcinogenic action of AFB₁, resulting in millions of dollars in annual losses to producers due to reduced growth rate, increased susceptibility to disease, reduced egg production and other adverse effects. The extreme sensitivity of turkeys and other poultry to AFB₁ is associated with efficient hepatic cytochrome P450-mediated bioactivation and deficient detoxification by glutathione S-transferases (GST). Discerning the biochemical and molecular mechanisms of this extreme sensitivity of poultry to AFB₁, will contribute in the development of novel strategies to increase aflatoxin resistance. Since AFB₁ is an unavoidable contaminant of corn-based poultry feed, chemoprevention strategies aimed at reducing AFB₁ toxicity in poultry and in other animals have been the subject of numerous studies. This brief review summarizes many of the key recent findings regarding the action of aflatoxins in poultry.     

伏马毒素B1对小鼠血液学指标及凋亡的影响

为探讨伏马毒素B1(FB1)对小鼠血液学指标及细胞凋亡的影响,试验选用昆明小鼠饲喂含FB1的饲料,连续45 d后称量体重并计算肾脏、脾脏和肝脏脏体比,测定血常规和血液生化指标,采用Tunel法检测脾脏细胞凋亡的变化,qPCR测定肝脏、脾脏和肾脏中凋亡相关基因的mRNA表达量.结果表明:浓度为36.82 mg/kg的FB...     

几种脱毒剂对黄曲霉毒素B_1和玉米赤霉烯酮体外吸附脱毒效果的比较研究

文章采用酶联免疫法(ELISA),分析比较了市场上10种常见脱毒剂对黄曲霉毒素B1和玉米赤霉烯酮的体外脱毒能力。结果显示,不同的脱毒剂脱毒效果不同,且经过特殊方式处理后的蒙脱石不仅对黄曲霉度B1和玉米赤霉烯酮具有较好的吸附脱毒能力,其复合物稳定性也较好。     

Experimental combined aflatoxin B1 and ochratoxin A intoxication in pigs

Twenty-one pigs weighing approximately 18 kg were placed in 7 groups of 3 and given diets containing respectively aflatoxin B1 alone at 0.375 and 0.0750 mg/kg, ochratoxin A alone at 1 and 2 mg/kg, 0.375 mg/kg of aflatoxin B1 plus 1 mg/kg of ochratoxin A and 0.750 mg/kg aflatoxin B1 and 2 mg/kg of ochratoxin A. The remaining group served as untreated control. At the respective dose levels, pigs receiving similar doses of ochratoxin A alone or in combination with aflatoxin B1, were similarly affected, the clinical effects of aflatoxin having been mostly obscured by those due to ochratoxin A. Mild degenerative hepatic changes typical of aflatoxicosis were observed in pigs fed this toxin alone or in combination with ochratoxin A. In kidneys of pigs fed diet containing 1 and 2 mg of ochratoxin A alone changes included interstitial fibrosis of the vortex and dystrophy and degeneration of the tubular epithelium. Similar lesions but less pronounced fibrosis were found in kidneys of pigs receiving both toxins. The respective lower dose levels of mycotoxins selected were judged to be about the no-effect levels for each dosed separately under the conditions of the trial. Such levels have been found not infrequently on mould affected grain and stock foods. The result highlights the difficulties that may be experienced in the recognition of such multimycotoxicoses as they are likely to occur in the field and indicate the need for toxicological analysis as well as pathological investigation in establishing a diagnosis.