T-2毒素和HT-2毒素检测方法的研究进展

T-2毒素和HT-2毒素属于单端孢霉烯族毒素。T-2毒素是A类单端孢霉烯族毒素中毒性最强的一种真菌毒素,HT-2毒素为T-2毒素在体内与体外最为主要的代谢产物,二者在自然界中分布广泛。对T-2毒素和HT-2毒素检测方法的研究进展进行综述,对二者常见检测方法的优点和缺点进行分析,以期为T-2毒素和HT-2毒素检测方法的科学选择提供参考。     

猪肉和鸡肉中脱氧雪腐镰刀菌烯醇和T-2毒素酶联免疫吸附检测方法的建立

为保障动物源性食品安全,本研究建立了分别检测猪肉和鸡肉中脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)和T-2毒素残留的间接竞争酶联免疫吸附法.结果显示,该方法在猪肉和鸡肉样本中DON的检测限分别为34.9和43.5 μg/kg,添加回收率为72.7%~97.1%,变异系数小于8.7%;T-2毒素的检测限分别为33.7和28.7 μg/kg,添加回收率为72.1%~95.0%,变异系数小于11.3%.该方法灵敏度高、准确、简便,适用于猪肉和鸡肉中DON和T-2毒素残留的快速检测.     

T-2毒素毒性作用研究进展

T-2是A类单端孢霉烯族化合物中毒性最强的一种,对动物机体具有较强的危害,可造成多个系统出现中毒效应。作者主要对T-2毒素对动物的广泛毒性作用进行论述,且对下一步的研究方向进行了展望。     

T-2毒素及其对关节软骨和心肌毒性研究进展

T-2毒素是A族单端孢霉烯族毒素中毒性最强的毒素,也是我国两种地方病,即大骨节病和克山病最可能的致病因素,主要对关节软骨及心肌有毒害作用。T-2毒素可以诱导细胞凋亡,引起家畜、家禽关节超微结构的改变和关节软骨细胞的损伤;还能影响心肌离子通道电活动,影响脂质过氧化物代谢,也能改变心肌超微结构;微量元素硒对T-2毒素致关节软骨和心肌损害有明显的保护作用。大骨节病和克山病的高发地区粮食中T-2毒素含量偏高20%左右,所以大骨节病和克山病可能和T-2毒素中毒有关。     

T-2毒素研究进展

T-2毒素是污染我国饲料的主要霉菌毒素,主要危害动物的造血组织和免疫器官,引起出血性综合征,出现白细胞减少、贫血,使胃肠道功能受损等,对畜禽健康和畜牧业生产的危害很大.本文主要从T-2毒素的一般性质、产毒菌株、毒性效应、毒性机制及预防控制等方面作了论述.     

T-2毒素免疫毒性研究现状

T-2毒素的免疫毒性具有矛盾性和复杂性。低剂量T-2毒素可提升动物对病原体的抵抗力,高剂量T-2毒素则大大降低动物的免疫力。T-2毒素暴露时间早于病原体可增加动物免疫抵抗力,反之或毒素与病原体同时暴露,则降低动物对病原体的抵抗力。近期研究发现,细胞凋亡/存活通路维持毒素免疫调控动态平衡,自噬在免疫调控中发挥着关键而复杂的作用,但T-2毒素免疫调控中是否存在类似"免疫逃避"机制亟待研究。论文综述了T-2毒素免疫毒性的矛盾性,并重点讨论了其潜在的分子机制,为单端孢霉烯族毒素的免疫毒性和动物疫病防控研究提供参考。     

T-2毒素的毒性作用及其诱导细胞凋亡机制概述

T-2毒素是一种毒性作用很强的霉菌毒素,是以镰刀菌属为主要产毒菌株所产生的一种A类单端孢霉烯族毒素,在多种谷物中的污染水平较高,通过食物摄入后在人类和动物机体内产生一系列毒性作用,严重威胁人类和动物的健康。论文从T-2毒素的理化性质、产毒菌株、毒性作用及对细胞凋亡的作用机制进行了简述,重点介绍了T-2毒素在免疫系统、消化系统和肝脏毒性、神经和皮肤毒性、血液毒性、生殖毒性方面的研究进展,以及T-2毒素通过线粒体信号通路介导细胞凋亡机制的研究进展,为T-2毒素的深入研究提供参考。     

低剂量T-2毒素对雏鸡免疫器官及血清生化指标的影响

为探讨低剂量T-2毒素(＜100 μg/kg)对雏鸡的免疫器官以及血清生化指标的影响,选用50只5日龄雏鸡,随机分为5组,分别为空白对照组、染毒1、2组、维生素E拮抗组和溶剂对照组进行研究.结果显示,鸡的部分免疫器官如脾脏、胸腺及法氏囊明显萎缩,免疫功能下降.血清中除LDH变化不明显外,其余9项指标变化均较明显:与对照组相比,ALB、TP、ALP、GOT、GPT随给毒剂量的增加而下降;r-GGT、GLU、Urea均随给毒剂量的增加而上升.     

T-2毒素的生物鉴定、提取及对动物的毒性

用家兔皮肤毒性试验测得三线镰刀菌污染玉米中T—2毒素的含量约为1.8g/kg试验灵敏度为0.08μg.此霉玉米经提取纯化后得白色针状结晶,根据毒素结晶的熔点、C、H元素含量、红外光谱、质谱碎片峰及1H核磁共振谱确证为T-2毒素,纯度为95.84%.毒素对锦鲤鱼苗72、96、120的LD_(50)分别为0.0847±0.0034ppm,0.0760±0.0053ppm,0.0705±0.0036ppm.每天连续口服毒素0.5～1mg/kg体重,可引起犬的出血性综合征,表现为呕吐、便血,尸检见肠道出血坏死,且充满大量的血液;组织学检查表明,肠粘膜广泛的出血坏死,牌小体萎缩和数量减少,骨髓造血细胞消失.将毒素给小鼠连续灌胃(2mg/kg体重),可引起骨髓核细胞数下降,但停毒后,逐渐恢复到正常水平.     

T-2毒素致猪肾细胞损伤及氧化应激相关机理的研究

试验旨在研究T-2毒素对猪肾细胞(PK15)的毒性作用及其氧化应激反应。用不同浓度的T-2毒素处理细胞,通过MTT法检测细胞活性、测定细胞内乳酸脱氢酶(LDH)释放率及苏木素伊红(HE)染色观察细胞形态变化评估T-2毒素对细胞的毒性作用;通过检测细胞内的活性氧(ROS)水平、丙二醛(MDA)含量及谷胱甘肽(GSH)含量、谷胱甘肽过氧化物酶(GPx)活性,评估不同剂量T-2毒素对细胞氧化应激水平的影响;检测Nrf2-ARE信号通路相关基因Nrf2、Keap1、GPx-1、Nqo1及Hmox1 mRNA的表达水平,分析T-2毒素对该信号通路的影响。结果表明,PK15细胞活性呈毒素剂量依赖性下降(P<0.05),LDH释放率呈毒素剂量依赖性上调(P<0.05);随T-2毒素剂量升高,细胞间隙逐渐增加,细胞固缩,细胞数量也随之减少。细胞内ROS阳性细胞率呈剂量依赖性升高,且T-2毒素为100 nmol/L时,ROS阳性细胞率显著高于其他剂量组(P<0.05);细胞内MDA含量与GPx活性呈毒素剂量依赖性升高(P<0.05),而GSH含量呈毒素剂量依赖性下降(P<0.05)。20、50及100 nmol/L的T-2毒素可显著上调Keap1、Gpx-1及Nqo1基因mRNA的相对表达量(P<0.05),且50 nmol/L的相对表达量最高。T-2毒素对K15细胞有毒性作用,可诱导其氧化损伤,且该氧化应激过程受Nrf2-AER信号通路调控。     

Generation of Airborne Particles from Horse Feeds Depending on Type and Processing

Among other factors (eg, bedding material, roughage), feed has an important effect on the airborne particle concentration in the stable air, in particular directly in the breathing zone of the horse during feeding. Therefore, this study was designed to analyze and compare the generation of different airborne particle fractions of diverse feed types and feed processing techniques under standardized laboratory conditions. Oats and barley as well as two commercially formulated ready-prepared pellets and two different commercially formulated ready-prepared mixes were analyzed. Oats were subjected to four different forms of processing (whole uncleaned, whole cleaned, rolled uncleaned, rolled cleaned), barley was subjected to steam flaking in addition to the same forms of processing as oats. In total, 13 feeds were analyzed. Airborne particle concentrations were detected online with a gravimetrically measuring analyzer that was equipped successively with different inlets to measure the particle fractions PM 1, PM 2.5, PM 10, and PM 20. The measurements were carried out in a closed chamber (1 × 1 × 1.5 m) including a bowl (diameter = 0.5 m), which simulated the trough. The sample inlet was situated at a height of 1.0 m above the bowl. Rolling oats and barley led to a significantly increased generation of the PM 20 fraction and a significantly decreased generation of the PM 2.5 fraction. The mechanical cleaning of oat and barley brings a clear decrease in dust generation from straights whether they are left whole or are rolled after cleaning. A considerable reduction in dust generation can be achieved if steam-flaked barley or commercially prepared feeds are used.     

17种植物性饲料原料中伏马毒素(B1+B2)、赭曲霉毒素A、T-2毒素、黄曲霉毒素B1污染状况调查检测分析

为了解掌握伏马毒素（B₁+B₂）、赭曲霉毒素A、T-2毒素、黄曲霉毒素B₁在植物性饲料原料中的污染状况,指导饲料生产企业和养殖企业开展霉菌毒素防控,降低霉菌毒素对饲料产品质量及畜禽养殖危害,减少经济损失,2019年对17种62份植物性饲料原料进行采集,采用液相色谱—串联质谱法、免疫亲和柱净化—高效液相色谱法检测,依据《饲料卫生标准》（GB 13078—2017）判定分析。结果表明：伏马毒素（B₁+B₂）、赭曲霉毒素A、黄曲霉毒素B₁在17种植物性饲料原料中的污染状况差别明显,伏马毒素（B₁+B₂）、赭曲霉毒素A、黄曲霉毒素B₁平均检出率分别为37.09%、8.06%、29.03%,最大检测值分别为15.96 mg/kg、26.60 μg/kg、351.00 μg/kg。从检测结果得出,4种霉菌毒素在17种植物性饲料原料中的污染较重,整体污染率达48.40%,玉米皮、喷浆玉米皮、花生粕3种植物性饲料原料中黄曲霉毒素B₁超标,污染率与超标率不一定呈正比,表明霉菌毒素在植物性饲料原料中污染普遍,对饲料产品及养殖安全造成严重影响。针对该问题,提出控制植物性饲料原料质量建议,为今后控制饲料原料中霉菌毒素含量提供参考。     

T-2毒素对BALB/c小鼠生长性能、血液指标和抗氧化能力的影响

本试验旨在研究T-2毒素对BALB/c小鼠生长性能、血常规指标、血清生化指标和肝脏抗氧化能力的影响。选用平均体重约为20 g的BALB/c小鼠80只,随机分成4个组,每个组20个重复,每个重复1只小鼠。4个组分别为对照组和3个不同T-2毒素剂量组,即0.4、1.0和2.5 mg/kg BW组,连续灌服28 d。结果表明,2.5 mg/kg BW组小鼠死亡率达25%,平均日增重和平均日采食量极显著降低(P0.01),心脏、肝脏、脾脏、肺脏、肾脏和大脑的脏器系数显著或极显著增加(P0.05或P0.01),睾丸、精囊腺、子宫和卵巢等生殖系统脏器系数显著或极显著降低(P0.05或P0.01)。与对照组相比,0.4和1.0 mg/kg BW组肝脏脏器系数极显著增加(P0.01),白细胞(WBC)、淋巴细胞(LY)、单核细胞(MO)、中性粒细胞(GR)数量均显著或极显著增高(P0.05或P0.01)。与对照组相比,2.5 mg/kg BW组MO、GR、血小板(PLT)数量极显著增高(P0.01),但红细胞数量(RBC)和血红蛋白(HGB)含量显著或极显著降低(P0.05或P0.01)。血清生化指标显示,随T-2毒素剂量的增加,葡萄糖(GLU)、尿素(urea)、肌酐(CRE)含量和碱性磷酸酶(ALP)、丙氨酸氨基转移酶(ALT)活性呈增加趋势,但甘油三酯(TG)和白蛋白(ALB)含量呈降低趋势,与对照组相比均差异显著或极显著(P0.05或P0.01)。随T-2毒素剂量的增加,小鼠肝脏组织中丙二醛(M DA)含量呈增加趋势,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧化物酶(GSH-Px)活性呈降低趋势。由此可知,T-2毒素剂量在低于1.0 mg/kg BW时对BALB/c小鼠具有免疫刺激作用,高剂量的T-2毒素抑制动物生长性能、引起肝脏和肾脏组织损伤、对肝脏的抗氧化能力也具有显著的抑制作用,呈剂量效应关系。     

Investigation on trichothecene-stimulated lipid peroxidation and toxic effects of trichothecenes in animals

Three experiments were performed with mice intoxicated with trichothecene-contamined feed or directly into the stomach. Lipid peroxidation was estimated by the TBA value from liver samples, but since such a test seldom provided reliable results, lipid hydroperoxides and total carbonyl were also analyzed. The formation of aldehydes and ketones was compared in vivo and in vitro. The same investigations were conducted on chickens, rainbow trouts and numerous fur animals suspected of chronic intoxication by trichothecenes. The vitamin A concentration was used as a parameter to detect alterations caused in chickens by trichothecenes. Our investigation provided evidence that lipid peroxidation is associated with trichothecene poisoning. The T-2 toxin, even in small concentrations, seems to induce strong lipid peroxidation. When DON and 3-AcDON were given together at a dosage of 180 micrograms/kg feed, 1 week's feeding caused clear lipid peroxidation in mice. Particular attention should be paid to the fact that mycotoxins may already be present in the feed before any experiment is conducted.     

脱氧雪腐镰刀菌烯醇导致厌食和呕吐的机制研究进展

由镰刀菌产生的脱氧雪腐镰刀菌烯醇(DON)广泛存在于谷物及其加工产品中,对动物和人类健康有着潜在的危害。DON具有多方面的毒性作用,而厌食和呕吐是机体摄入DON后出现的最典型症状,厌食和呕吐的产生主要归因于DON对中枢神经系统和胃肠道食欲因子的影响。DON可直接作用于中枢神经系统的呕吐中枢产生呕吐反射,同时激活下丘脑神经元分泌食欲调节因子影响采食;DON可诱导肠内分泌细胞分泌肽YY、胆囊收缩素等食欲调节因子从而引发厌食;DON对中枢神经系统和胃肠道分泌的影响又可通过肠-脑轴产生关联;此外,细胞因子及肠道微生物也部分参与了反应的介导。本文综述了DON诱发机体出现厌食和呕吐的可能机制,以期为找到相应解决措施提供理论指导。     

Influence of Feeding Horses a High Fiber Diet With or Without Live Yeast Cultures Supplementation on Feed Intake,Nutrient Digestion,Blood Chemistry,Fecal Coliform Count,and In Vitro Fecal Fermentation

Sixteen Quarter Horse mares (body weight: 450–500 kg) were used in a complete randomized design to determine the effects of feeding horses a high fiber diet with or without yeast cultures addition on nutrient intake and digestion, blood chemistry, fecal coliform count, and in vitro fecal fermentation. The treatments were (1) a basal diet without yeast cultures addition (control treatment), (2) control diet plus Procreatin 7 at 15 g/mare/d (P7 treatment), (3) control diet plus Biocell F53 at 11 g/mare/d (F53 treatment), or (4) control diet plus Biosaf SC47 at 15 g/mare/d (SC47 treatment). The basal concentrate diet consisted of a mixture of 50% commercial concentrates and 50% wheat bran fed at 4 kg/mare and offered twice daily at 04:00 and 16:00 hours, while oat straw was offered ad libitum at 05:00 and 17:00 hours. The mares fed the F53 had higher (P < .05) oat straw and total nutrient intakes compared to the control diet. Addition of Biocell F53 and Biosaf SC47 yeast cultures increased (P < .05) all nutrients' digestibilities. Feeding the yeast cultures resulted in higher crude protein (P = .029), neutral detergent fiber (P = .042), and acid detergent fiber (P = .035) digestibilities compared to the control diet. The SC47 treatment had lower blood total protein (P = .014) than the control treatment. Higher (P < .05) asymptotic in vitro fecal gas production was obtained with F53 treatment compared to SC47 treatment without differences between F53, P7, and control treatments. Increased methane production was obtained (P < .05) with F53 and SC47 treatments compared to the control treatment. It can be concluded that daily addition of Biocell F53 yeast culture at 11 g/mare/d resulted in higher feed intake and nutrients digestibility without affecting the mare's health.     

T-2毒素对大鼠离体培养卵巢颗粒细胞凋亡的影响

将未成熟的Wistar大鼠卵巢颗粒细胞进行原代培养,用不同浓度的T-2毒素染毒细胞24 h.染毒结束后,采用MTT法检测细胞相对活力,荧光染料Hoechst 33258检测卵巢颗粒细胞的凋亡变化,RT-PCR检测凋亡调控基因Bcl-2、Bax和P53 mRNA的表达.结果显示,随着T-2毒素染毒剂量的增加,颗粒细胞的细胞活力逐渐下降;而细胞凋亡率、Bcb2、Bax、P53 mRNA表达水平、Bax mRNA/Bcl-2 mRNA比值则逐渐上升;除1 nmol/L剂量组外,其余各剂量组与对照组比较差异显著(P＜0.05).结果表明,T-2毒素可显著抑制大鼠卵巢颗粒细胞活力,诱导颗粒细胞凋亡,并呈浓度依赖关系.