旋毛虫成囊前期幼虫抗原保护性免疫的研究

目的比较旋毛虫成囊前期幼虫虫体抗原、排泄分泌抗原和表面抗原对小鼠产生的免疫保护作用。方法分别用旋毛虫成囊前期幼虫虫体抗原、排泄分泌抗原、表面抗原免疫小鼠,同时设佐剂组和阴性对照组,间隔7d免疫1次,共3次。末次免疫后7d,每只小鼠用200条旋毛虫感染期幼虫经口进行攻击感染。感染后7d和30d分别检查各组小鼠肠道成虫数和肌幼虫数;用ELISA测血清中抗旋毛虫肌幼虫IgG抗体。结果虫体抗原、排泄分泌抗原、表面抗原和佐剂组的成虫减虫率分别为84．89％、89．73％、85．65％、2．57％;肌幼虫减虫率分别为71．71％、80．98％、73．66％、5．60％。排泄分泌抗原组、表面抗原组的成虫减虫率（P均〈0．05）及肌幼虫减虫率（P均〈0．01）均高于虫体抗原组。各免疫组小鼠血清IgG抗体滴度明显升高,虫体抗原组、排泄分泌抗原组和表面抗原组的几何平均倒数滴度分别为2798．89、3474．51、2984．83,分别为阴性对照组（459．32）的6．09、7．56、6．50倍。结论旋毛虫成囊前期幼虫虫体抗原、排泄分泌抗原和表面抗原均能诱导宿主产生较强的抗攻击感染保护力。成囊前期幼虫的排泄分泌抗原显示出更强的免疫原性。     

镜检法与贝氏法对肉类中旋毛虫成囊前幼虫的检验效果

目的观察镜检法（trichinelloscopy）与贝氏法（Baermann’s technique）对肉类中旋毛虫成囊前幼虫（pre-encap-sulated larvae,PEL）检验的效果。方法将80只昆明小鼠随机分为8组（每组10只）,每只感染旋毛虫肌幼虫300条,感染后14～21d每天剖杀1组,应用贝氏法检查小鼠肌肉中的PEL（9～16日龄）,用镜检法检查膈肌中的PEL,用ELISA检测鼠血清抗旋毛虫抗体。另取12只小鼠,用于观察消化法对旋毛虫感染后17～19d（12～14日龄）PEL存活率的影响。结果小鼠感染旋毛虫后14和15d镜检法幼虫检出率分别为50.0%和89.0%,感染后16～21d检出率均为100%。感染后14～21d贝氏法的检出率均为100%;ELISA检测血清抗体阳性率为11.1%～40.0%。感染后14d贝氏法的PEL检出率与镜检法比较差异有统计学意义（χ^2=5.333,P〈0.05）;观察期间ELISA检测的抗体阳性率均显著低于镜检法和贝氏法的幼虫检出率（χ^2=18.9,P〈0.05）。感染后17～19d,小鼠肌肉消化4h的幼虫存活率均明显低于消化1h的存活率（χ^217=117.56,χ^218=37.48,χ^219=96.73,P均〈0.05）。结论旋毛虫感染后17～19d的成囊前幼虫不能完全抵抗胃蛋白酶的消化作用;对肉类中旋毛虫成囊前幼虫的检疫效果,贝氏法优于镜检法。     

旋毛虫成囊前期幼虫的收集

目的 探索旋毛虫成囊前期幼虫的收集时间与方法.方法 20只成年大鼠,每只大鼠经口感染3000条旋毛虫脱囊幼虫,分别于第14、15、16、17、18、19、20天将大鼠处死,用人工胃蛋白酶消化肌肉收集旋毛虫.结果 感染后第14、15、16大膈肌均未见旋毛虫,第17、18、19、20天膈肌有旋毛虫的侵入并逐渐增多;第14、15、16天均未收集到旋毛虫,第17、18、19、20天平均每只大鼠分别收集5000、8000、10000、30000条旋毛虫.结论 旋毛虫在感染后第20天是旋毛虫成囊前期幼虫收集的最佳时期.人工胃蛋白酶消化肌肉可以收集成囊前期幼虫.     

Ts21基因在旋毛虫不同期虫体的表达及特性的研究

目的观察旋毛虫Ts21基因在不同发育期虫体的表达及其特性。方法应用RT-PCR检测旋毛虫Ts21基因在成虫、新生幼虫、感染后15d的成囊前幼虫及感染后42d的成囊幼虫(肌幼虫)的转录情况;应用抗Ts21重组蛋白血清通过间接荧光抗体试验(IFA)对成囊前幼虫及肌幼虫冰冻切片抗原进行检测。应用抗Ts21重组蛋白血清对旋毛虫肌幼虫粗(可溶性)抗原及排泄分泌(ES)抗原进行Western-blot分析。结果RT-PCR发现旋毛虫成虫与感染后42d肌幼虫均扩增出一条分子量约540bp的特异性条带(Ts21基因目的条带),而新生幼虫与感染后15d成囊前幼虫则未扩增出目的条带;IFA结果表明抗Ts21重组蛋白血清只与感染后42d成囊幼虫抗原发生阳性反应,而不与感染后15d的成囊前幼虫抗原发生阳性反应。Western-blot结果显示抗Ts21重组蛋白血清只与旋毛虫肌幼虫粗抗原和ES抗原中Mr 21 000的单一蛋白条带发生阳性反应。结论旋毛虫Ts21基因的表达具有期特异性,Ts21蛋白是旋毛虫肌幼虫ES抗原中的一部分。     

旋毛虫幼虫在宿主肌组织中分布的影响因素

旋毛虫幼虫在宿主肌组织中的分布受多种因素的影响, 如宿主种类、 肌肉生理状况、 旋毛虫种别、 旋毛虫幼虫能否成囊、 感染量等。本文对旋毛虫幼虫在宿主肌组织分布的影响因素作一综述。     

旋毛虫成囊前期幼虫编码31kDa抗原基因的分子克隆及序列分析

目的　克隆旋毛虫河南株成囊前期幼虫编码 31kDa抗原基因 (TspE1)片段 ,并测定其基因序列 ,以了解该基因序列与已报道虫株的差异。方法　根据TspE1基因已知序列设计合成一对引物 ,采用RT -PCR技术获取旋毛虫成囊前期幼虫目的基因 ,PCR产物经纯化后用BamHⅠ、HindⅢ进行双酶切 ,定向克隆入pC18质粒 ,转化大肠杆菌JM10 9;重组质粒用BamHⅠ +HindⅢ酶切及PCR扩增鉴定。用Sanger双脱氧链终止法进行DNA序列测定 ,应用DNASIS软件进行同源性比较及预测抗原表位。结果　RT -PCR扩增获得成囊前期幼虫TspE1基因 (约 870bp) ,EcoRⅠ酶切鉴定正确 ;筛选出 7个阳性克隆 ,对目的基因的测序结果显示有 5种类型 ,但都与GenBank中的TspE1基因序列及由其推测的氨基酸序列有较高同源性 ,尤其是Ts HN3核苷酸及氨基酸序列同源性分别达 99 6 %和 98 9% ;TspE1基因中可能存在 7个抗原表位。 结论　应用RT -PCR技术扩增出旋毛虫河南株成囊前期幼虫编码 31kDa抗原结构基因 ,证实TspE1基因在成囊前期幼虫已有表达 ;结果还提示在旋毛虫河南株之间可能存在有遗传多态性     

肉类中旋毛虫成囊前期幼虫检验方法及其影响因素

目的观察人工消化法(artificial digestion method)和贝氏法(Baermann's technique)检验肉类中旋毛虫成囊前期幼虫(pre-encapsulated larvae,PEL)的效果及其影响因素。方法将45只小鼠随机分为3组(每组15只),分别经口感染20、10、5条旋毛虫肌幼虫,感染后18d剖杀,将3组小鼠肌肉剪碎后,分别应用国际旋毛虫病委员会(International Commis-sion on Trichinellosis,ICT)推荐的消化法(简称ICT-消化法)、国家标准-猪旋毛虫病诊断技术(GB/T186452-2000)中规定的消化法(简称国标-消化法)及贝氏法进行PEL的检验。结果ICT-消化法、国标-消化法与贝氏法对感染20条旋毛虫幼虫的小鼠肌肉中PEL的检出率均为100%(15/15)(χ220=0.000,P>0.05);感染10条幼虫小鼠肌肉,3种方法的PEL检出率分别为93.33%(14/15),93.33%(14/15)及100%(15/15)(χ120=1.645,P>0.05);感染5条幼虫的小鼠肌肉,3种方法的PEL检出率分别为63.33%(19/30),90%(27/30)及100%(30/30)(χ52=18.866,P<0.05)。感染旋毛虫后18d的小鼠肌肉分别消化1h、2h、3h、4h与5h,PEL死亡率分别为8.49%(53/624)、29.77%(181/608)、58.46(449/768)、67.83%(407/600)、84.70%(515/608),PEL的死亡率随消化时间的延长而升高(χ2=920.772,P<0.05)。结论对肉类中旋毛虫成囊前期幼虫检疫时,贝氏法明显优于消化法。     

旋毛虫成囊前期幼虫抗原结构基因TspE1的克隆与表达

目的　克隆和表达旋毛虫河南地理株成囊前期幼虫编码 3 1kDa抗原的结构基因 (TspE1)。　 方法　大鼠感染旋毛虫后第 17天收集成囊前期幼虫 ,提取虫体的总RNA。通过RT PCR特异性扩增目的基因 ,构建重组质粒pUC18 Ts HN3 ,将重组质粒 pUC18 Ts HN3中的目的基因亚克隆入原核表达载体pGEMEX 1,构建重组子 pGEMEX 1 Ts HN3 ,经IPTG诱导 ,在E .coliJM 10 9(DE3 )中表达。对表达产物进行SDS PAGE分析和Westernblotting鉴定。　 结果　SDS PAGE显示目的基因在大肠杆菌中获得高效表达 ,重组蛋白的分子量为 3 1kDa ,以诱导 4h时表达量最多。薄层凝胶光密度扫描分析结果显示 ,表达的融合蛋白量约占细菌总蛋白的 2 6%。Westernblotting证实 ,融合蛋白条带能被感染旋毛虫的大鼠血清及旋毛虫病患者血清识别。　结论　旋毛虫河南地理株成囊前期幼虫抗原结构基因TspE1克隆和原核表达成功。     

免疫血清对旋毛虫感染性幼虫侵入肠上皮细胞及其发育的影响

目的观察旋毛虫感染性幼虫排泄分泌(ES)抗原与旋毛虫感染性幼虫表面抗原免疫鼠血清对幼虫侵入HCT-8肠上皮细胞及其发育的影响。方法将旋毛虫感染性幼虫接种至半固体培养基(RPMI1640培养基+1.75%琼脂糖)+HCT-8细胞中,37℃5%CO2培养12、24、36、72和96h后镜下观察幼虫发育情况;将幼虫接种至含免疫血清的半固体培养基+HCT-8细胞中,培养15min后镜下观察幼虫形态及其对肠上皮细胞的侵入情况,36h后应用间接荧光抗体试验(IFAT)观察幼虫蜕皮,并计数Ⅰ期和Ⅱ～Ⅳ期幼虫。结果幼虫在半固体培养基培养12h可侵入HCT-8细胞单层,36～72h幼虫可蜕皮1～2次,培养96h可见早期成虫。在含ES抗原免疫血清与感染鼠血清条件下培养15min,幼虫头端可见免疫复合物形成的帽样结构,但在含表面抗原免疫血清、正常鼠血清或不含免疫血清条件下培养的幼虫头端则无帽样结构,头端带有帽样结构的幼虫不能侵入HCT-8细胞单层。在含ES抗原与表面抗原免疫血清条件下发育至Ⅱ～Ⅳ期幼虫的百分比(2.25%、2.2%)均明显低于含正常鼠血清条件下培养的幼虫(24.7%)(P0.05)。结论旋毛虫ES抗原免疫血清可阻止幼虫对肠上皮细胞的侵入,ES抗原及表面抗原免疫血清均可阻止部分幼虫的发育(蜕皮)。     

妊娠对小鼠旋毛虫感染免疫应答的影响

目的 研究妊娠对小鼠旋毛虫感染免疫应答的影响。 方法 6只孕鼠分别经口感染300条旋毛虫肌幼虫,ELISA检测感染后不同时间血清抗体水平。感染后6周剖杀,消化全身肌肉计算每克肌肉虫荷（lpg）。测定孕鼠感染后1～4周血清介导的抗体依赖细胞介导的细胞毒性作用（ADCC）对成囊前期幼虫（PEL）的杀伤作用。观察孕鼠感染旋毛虫后第6、8和12天的肠道虫荷及雌虫体外生殖力指数。对6只处女鼠肌肉注射孕酮,观察其感染旋毛虫后6周的血清抗体水平与肌肉虫荷。 结果 孕鼠感染旋毛虫后2周的血清抗体水平（A492=0.113）显著高于未孕鼠（A492=0.078）（F=21.390,P＜0.05）。孕鼠感染后6周的每克肌肉虫荷（1 251±450）明显低于未孕鼠（2 310±1 123）（t=2.419,P＜0.05）。孕鼠感染后2周血清介导的ADCC导致成囊前期幼虫的死亡率（42.6%）显著高于未孕鼠（26.9%）（F=1.195,P＜0.05）。孕鼠感染后第6、8和12天的肠道虫荷与未孕鼠相比差异均无统计学意义（Z6=-1.185,Z8=-0.149,Z12=-0.0289,P＞0.05）,感染后第6和8天孕鼠与未孕鼠的雌虫生殖力指数间的差异亦无统计学意义（Z6=-0.149,Z8=-1.043,P＞0.05）。孕酮注射处女鼠感染旋毛虫后6周的血清抗体水平（A492=0.299）显著高于对照组（A492=0.191）（t=2.955,P＜0.05）,但其每克肌肉虫荷（1 457±551）与对照组（1 235±439）相比差异无统计学意义（t=0.726,P＞0.05）。 结论 妊娠在小鼠抗旋毛虫感染的免疫应答中具有协同作用,其机制可能与孕鼠感染旋毛虫后早期血清抗体水平升高及其介导的ADCC对成囊前期幼虫的杀伤作用增强等有关。     

旋毛虫排泄分泌抗原对小鼠的保护性免疫

目的比较旋毛虫成虫排泄分泌抗原(ES抗原)、肌幼虫ES抗原、成虫和肌幼虫ES混合抗原对小鼠的免疫保护作用。方法用生理盐水培养法从培养液中提取成虫ES抗原、肌幼虫ES抗原,分别用成虫ES抗原、肌幼虫ES抗原、成虫和肌幼虫ES混合抗原免疫小鼠,同时设佐剂组和对照组,间隔7d共免疫3次。末次免疫后7天,每只小鼠用200条旋毛虫感染期幼虫经口进行攻击感染。感染后7天和30天检查各组小鼠肠道成虫数和肌幼虫数。结果旋毛虫成虫ES抗原组、肌幼虫ES抗原组、成虫和肌幼虫ES混合抗原组的成虫减虫率分别为87.95%、69.48%、84.34%,肌幼虫减虫率分别为74.79%、87.97%、86.87%。成虫ES抗原组、成虫与肌幼虫ES抗原混合组的成虫减虫率均高于肌幼虫ES抗原组(P均<0.05)。肌幼虫ES抗原组、成虫与肌幼虫ES抗原混合组的肌幼虫减虫率均高于成虫ES抗原组(P均<0.01)。结论旋毛虫成虫和肌幼虫ES混合抗原均能诱导小鼠产生抗成虫及肌幼虫较强的免疫力。     

旋毛虫成虫抗原的免疫保护性研究

目的 比较旋毛虫成虫虫体抗原、排泄分泌抗原和表面抗原对小鼠产生的免疫保护作用。 方法 检查免疫鼠和对照鼠肠道成虫、肌幼虫和血液中的嗜酸性粒细胞数;用ELISA测血清中抗旋毛虫肌幼虫IgG抗体滴度。 结果旋毛虫成虫虫体抗原、排泄分泌抗原和表面抗原免疫组的成虫减虫率分别为84.48％、89.98％和85.16％;肌幼虫减虫率分别为69.82％、78.80％和73.94％。3种抗原免疫组小鼠血中的嗜酸性粒细胞(EOS)数明显增多,血清中IgG抗体滴度明显升高,IgG抗体的几何平均倒数滴度(GMRT)分别是未免疫组的6.96、7.99和6.06倍。 结论 旋毛虫成虫虫体抗原、排泄分泌抗原和表面抗原均能诱导宿主产生较强的抗攻击感染保护力,且可激发特异性体液免疫和细胞免疫。成虫的排泄分泌抗原显示出更强的免疫原性。     

旋毛虫肌幼虫排泄分泌物中特异性诊断抗原的研究

目的　寻找旋毛虫肌幼虫排泄分泌(ES)物中的特异性诊断抗原。　方法　应用SDSPAGE和Western印迹对旋毛虫肌幼虫体外培养18、30h后的ES抗原中的蛋白组分进行研究。　结果　旋毛虫肌幼虫培养18、30h后得到的ES抗原组分大致相同,两种ES抗原中主要蛋白带的分子量为112、110、108、97、53、49、45、42、35、23和16kDa。18hES抗原中的102、97、95和53kDa以及30hES抗原中的53、49、45和43kDa均与并殖吸虫病、华支睾吸虫病、日本血吸虫病及囊尾蚴病患者血清发生明显的交叉反应。ES抗原中的23kDa蛋白组分只与旋毛虫感染的大鼠、小鼠及患者血清反应,而不与上述其它寄生虫感染者、正常大鼠和小鼠及正常人血清发生交叉反应。　结论　旋毛虫肌幼虫ES抗原中的23kDa蛋白组分为旋毛虫肌幼虫的特异性抗原,可用于旋毛虫病的血清学诊断及血清流行病学调查。     

旋毛虫成虫可溶性抗原和排泄分泌抗原对小鼠免疫保护作用的比较研究

目的　比较旋毛虫成虫可溶性抗原和排泄分泌抗原对小鼠的免疫保护作用。方法　收集人工感染大鼠小肠内的成虫, 经研磨和冻融制备成虫可溶性抗原。采用体外培养的方法从培养液中提取旋毛虫成虫排泄分泌抗原。分别用两种抗原免疫小鼠, 间隔１ 周共免疫３ 次, 末次免疫后１ 周, 每只小鼠攻击感染１００ 条旋毛虫感染性肌肉幼虫。感染后１ 周检查小鼠小肠内成虫数量和雌虫生殖力, 感染后５ 周检查肌肉幼虫负荷。结果　成虫可溶性抗原诱导的成虫减虫率、新生幼虫减虫率和肌肉幼虫减虫率分别为７９５５ ％ 、６２２５ ％ 和６５０ ％ 。成虫排泄分泌抗原诱导的成虫减虫率、新生幼虫减虫率和肌肉幼虫减虫率分别是９７２７ ％ 、８６６０ ％ 和９００ ％ 。结论　实验结果表明旋毛虫成虫可溶性抗原和成虫排泄分泌抗原均能够诱导宿主产生较强的抗攻击感染的免疫力, 但后者的免疫原性更强。     

抗旋毛虫肌幼虫ES抗原IgY的制备及鉴定

目的制备抗旋毛虫肌幼虫排泄-分泌(excretory-secretory,ES)抗原的鸡卵黄免疫球蛋白(IgY),测定其效价及用于检测抗原的敏感性。方法 4只24w龄罗曼母鸡用旋毛虫肌幼虫ES抗原经大腿外侧与胸部肌肉免疫4次(首次剂量为500μg/只,加强剂量为250μg/只),每次间隔10d。取免疫前和首次免疫后42d的鸡蛋卵黄,用水稀释法提取IgY,考马斯亮蓝法测定蛋白含量,十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)、蛋白质印迹(Western blot)及间接荧光抗体试验(IFAT)对IgY进行分析,ELISA检测纯化后IgY的效价及检测抗原的敏感性。结果罗曼鸡经ES抗原免疫后,每枚鸡蛋经提纯后均可得到约70mg抗体,SDS-PAGE表明纯化的IgY有2条主要蛋白带,分子量为67kDa、23kDa,Western blot与IFAT发现提纯的IgY可识别肌幼虫虫体与ES抗原。IgY的抗体效价为1∶107,IgY-夹心ELISA检测旋毛虫抗原的敏感性为1.17ng/mL。结论制备的抗旋毛虫ES抗原的IgY具有较高的效价与敏感性。     

The influence of the procedure of excretory-secretory L1 trichinella spiralis antigen preparation on the efficiency of an ELISA test in pigs

BACKGROUND: Trichinellosis is a parasitic zoonosis transmitted to humans by consumption of raw or undercooked meat from animals infected by worms of the Trichinella genus. Every year seropositive cases are found among the human population and thus trichinellosis still remains an epidemiologically important disease in Poland. The usefulness of ELISA for anti-T. spiralis IgG detection in pigs is still limited by the nature of antigen. The objective in the present study was to compare the usefulness of excretory-secretory antigens of L1 T. spiralis for the serological detection of IgG antibodies in pigs. MATERIAL AND METHODS: The antigens were prepared in different laboratories: Ag ES L1 T. spiralis (N) in Germany, Ag ES L1 T. spiralis (W) in Italy and Ag ES L1 T. spiralis in Poland. Conventional, Iberian pigs were infected with 200, 1000 and 20 000 muscle larvae of T. spiralis. Serum samples were obtained at 5 and 1 dbi (day before infection), and 5, 10, 15, 20, 25, 30, 40, 50, 60 dpi (day post infection) and screened for specific IgG antibodies to excretory-secretory L1 T. spiralis antigens. Serum samples were obtained from the EU project TRICHIPORSE. The cut-off value of ELISA was determined on serum samples from 248 Trichinella-free pigs from Poznaii and Boza Wola, that were examined by artificial digestion. RESULTS: In pigs infected with 200 L1 T. spiralis larvae, specific IgG were detectable from 50 dpi, when the Ag ES L1 T. spiralis (N) was used, whereas when Ag ES L1 T. spiralis (W) and Ag ES L1 T. spiralis were used, the specific IgG were detectable from 40 dpi. In pigs infected with 1000 LI T. spiralis larvae, specific IgG was observed from 30 dpi when Ag ES L1 T. spiralis (W) and Ag ES L1 T. spiralis were used, but when Ag ES L1 T. spiralis (N) was used specific IgG were detectable from 40 dpi. In the group infected with the highest dose of T. spiralis larvae, specific IgG were detectable from 30 dpi when Ag ES L1 T. spiralis (N) and Ag ES L1 T. spiralis (W) were used, whereas when Ag ES L1 T. spiralis was used specific IgG were detectable from 20 dpi. The results strongly indicated that in the examined pigs, the specific IgG response against T. spiralis infection is dose dependent. Furthermore, it was shown that the high infectious dose induced earlier increasing of specific IgG response. Statistical analysis revealed a significant positive correlation between OD values obtained in procedures based on the three antigens. The results were statistically repeatable for procedures and for single pigs (P<0.01).     

The usefulness of ELISA test for early serological detection of Trichinella spp. infection in pigs

Trichinellosis is a parasitic zoonosis transmitted to humans through consumption of raw or undercooked meat from animals infected with nematodes of the Trichinella genus. Every year seropositive cases are found among the human population and thus trichinellosis still remains an epidemiologically important disease. The first step of the study was the optimization of a new ELISA method enabling an early and specific serological diagnosis of trichinellosis in pigs and wild boars using excretory-secretory (ES) antigens obtained from in vitro cultures of L1 T. spiralis. Serum samples were assayed for anti-T. spiralis IgG antibodies using the new ELISA protocol and a reference test--Standard manufactured by Institut Pourquier. The optimization involved the selection of suitable plates for antigen coating, dilution of sera and antibodies and their time of incubation. On the basis of the optimization a new ELISA procedure for the detection of IgG and IgM against T. spiralis was elaborated. Conventional, Iberian pigs and SPF (Specific Pathogen Free) pigs were infected with 200, 1000 and 20,000 muscle larvae of T. spiralis. Serum samples were obtained at 5 and 1 dbi (day before infection), and 5, 10, 15, 20, 25, 30, 40, 50, 60 dpi (day post infection) and screened for specific IgG antibodies against excretory-secretory L1 T. spiralis antigens. Serum samples were obtained from the EU project Trichiporse: "Safe pork and horse meat on EU markets: early and unbiased diagnostic tests for Trichinella". Field samples of conventional pigs (1474) and wild boars (1784) were obtained from slaughter houses in different parts of Poland. Pigs were examined for the presence of Trichinella spp. using the artificial digestion method. Only four pigs were naturally infected with T. spiralis, the remaining were Trichinella larvae free. ELISA was used to examine IgG levels against L1 T. spiralis in pig and wild boar sera. The usefulness of ELISA for anti-IgG detection in pigs is usually limited by the nature of the antigen. The antigens were prepared in different laboratories: in Germany--Ag ES L1 T. spiralis (N), Italy--Ag ES L1 T. spiralis (W)) and in Poland--Ag ES L1 T. spiralis. Cut-off values for ELISA along with the estimated sensitivity and specificity were calculated using different methods: S/P%, M+3SD and ROC (Receiver Operating Characteristic). In SPF and Iberian pigs inoculated with 200, 1000 and 20,000 L1 T. spiralis, specific antibodies were detected 40, 30 and 25 dpi, respectively, with the use of the Standard (reference test). The analysis of the two ELISA procedures demonstrated a high sensitivity and specificity for the newly elaborated test utilizing the Ag ES L1 T. spiralis. In conventional pigs infected with 20,000 L1 T. spiralis specific antibodies were detected from 20 dpi when employing the new protocol. Similar results for the Standard and new ELISA test were obtained for serum samples of conventional pigs infected with 200 and 1000 larvae, which became positive from 40 dpi and 30 dpi, respectively. The results showed that both: the Standard and new protocols were comparable, and based on this, the new test was applied for further research. Results obtained adopting the new protocol with three antigens showed that two of them: Ag ES L1 T. spiralis (W) and Ag ES L1 T. spiralis are similar. The specific IgG antibodies for infective doses of 200 and 1000 larvae for these antigens were detectable 40 and 30 dpi respectively. In pigs infected with the highest dose of T. spiralis larvae IgG antibodies were detectable from 20 dpi when Ag ES L1 T. spiralis was used. These results strongly indicate that in examined pigs, the specific IgG response to T. spiralis infection is dose dependant. Of 1474 examined pig sera only 0.99% gave a positive signal against ES L1 T. spiralis antigen. Of 1784 examined wild boars sera only 0.68 % gave positive results using the new ELISA protocol. ELISA is a useful method for detecting specific IgG antibodies in pigs experimentally infected with different doses of T. spiralis and naturally infected pigs. In pigs the specific IgG response is dose dependant. The Ag ES L1 T. spiralis increases the specifity of the method and reduces false positive results. Simultaneous use of both methods: digestion and ELISA for the diagnosis of Trichinella in naturally infected pigs and wild boars may increase the chances of eliminating meat infected with T. spiralis larvae.