旋毛虫肌幼虫特异性抗原的鉴定

目的 寻找诊断旋毛虫病的特异性抗原。方法 应用SDS—PAGE和Western blot对旋毛虫肌幼虫可溶性抗原中的蛋白组分进行研究。结果 旋毛虫肌幼虫可溶性抗原经SDS—PAGE后显示29条蛋白带，分子量范围在112—12kDa之间，其中65、43、42、31、30、20、17、16kDa为主带。112、110、108、102、97、95、65、63、58、55、53、49、45、43、42kDa蛋白组分与并殖吸虫感染的大鼠及患者血清、华支睾吸虫病、血吸虫病及囊尾蚴病患者血清均具有明显的交叉反应带；24—20kDa蛋白组分只与旋毛虫感染的大鼠、小鼠及患者血清反应，而不与其它寄生虫感染的动物或患者血清、正常大鼠和小鼠及正常人血清发生交叉反应。结论旋毛虫肌幼虫可溶性抗原中24—20kDa蛋白组分为旋毛虫肌幼虫的特异性抗原，可用于旋毛虫病的免疫学诊断及血清流行病学调杏。     

免疫层析试纸条诊断旋毛虫病的研究

目的建立一种能诊断人体旋毛虫病及动物旋毛虫感染的快速血清学方法。方法以胶体金标SPA和旋毛虫肌幼虫ES抗原制备免疫层析试纸条(immunochromatographic strip),对旋毛虫病及其它寄生虫病患者血清、旋毛虫及其它寄生虫感染的动物血清进行检测。结果试纸条检测旋毛虫病患者与旋毛虫感染的小鼠、大鼠、兔、猪血清的阳性率分别为100%(20/20)、97.87%(92/94)、100%(5/5)、100%(5/5)及100%(25/25),15min内肉眼可观察结果;其它寄生虫病(并殖吸虫病、血吸虫病、华支睾吸虫病、囊虫病及包虫病等)患者及正常人血清、其它寄生虫感染动物及正常动物血清均为阴性。试纸条和ELISA对100条幼虫感染小鼠血清检测的阳性率分别为91.3%(21/23)和95.7%(22/23)(χ2=0.36,P>0.05),两种方法对200～500条幼虫感染小鼠血清检测的阳性率均为100%(71/71)。试纸条对乡土旋毛虫、布氏旋毛虫、伪旋毛虫及纳氏旋毛虫感染小鼠血清检测的阳性率亦均为100%。试纸条在4℃可保存13个月,检测结果在室温可保存3个月。结论该试纸条可用于人体旋毛虫病和动物旋毛虫感染的快速血清学诊断,也可用于其它种旋毛虫感染的血清流行病学调查。     

肌幼虫可溶性抗原与ES抗原检测抗旋毛虫抗体效果的比较

目的比较旋毛虫肌幼虫可溶性抗原(SAg)与ES抗原(ESAg)检测抗旋毛虫抗体的效果。方法应用SAg-ELISA和ESAg-ELISA对旋毛虫病患者血清、感染旋毛虫的小鼠血清及肉汁、其他寄生虫感染人及动物血清进行抗旋毛虫抗体的检测。结果SAg-ELISA和ESAg-ELISA对10例旋毛虫病患者血清检测时抗体阳性率均为100%,但对10份正常人血清检测时SAg-ELISA的背景较深,两种抗原的A值相比较具有显著性差异(P<0.05);应用两种抗原对旋毛虫感染小鼠和正常小鼠血清及肉汁的检测结果与对人血清的检测结果相似。SAg与肝吸虫、肺吸虫、血吸虫等寄生虫感染人及动物血清均有交叉反应,而ESAg仅与1例肺吸虫病患者血清有交叉反应。结论旋毛虫肌幼虫SAg和ESAg检测抗旋毛虫抗体的敏感性相同,但ESAg的特异性优于SAg;肉汁也可作为样本进行抗旋毛虫抗体的检测。     

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、卫氏并殖吸虫及华支睾吸虫之间共同抗原的研究

目的鉴定旋毛虫、卫氏并殖吸虫及华支睾吸虫之间的共同抗原,避免血清学诊断这3种寄生虫病时的交叉反应。方法应用十二烷基硫酸钠-聚丙烯酸胺凝胶电泳(SDS-PAGE)和免疫印渍(Western blot)对旋毛虫肌幼虫、卫氏并殖吸虫成虫及华支睾吸虫成虫可溶性抗原中的蛋白组分进行研究。结果旋毛虫肌幼虫、卫氏并殖吸虫成虫及华文睾吸虫成虫3者相同蛋白带的分子量为108、65、53、43、42、31、25、16 kDa。免疫印渍结果表明,旋毛虫和卫氏并殖吸虫抗原中分子量为 65、58、53kDa的蛋白带均与旋毛虫感染的大鼠、小鼠及患者血清、肺吸虫感染的大鼠和患者血清发生反应;旋毛虫和华支睾吸虫抗原中分子量为108kDa的蛋白带均与旋毛虫感染的大鼠、小鼠及患者血清、肝吸虫病患者血清发生反应;而3种可溶性抗原中的53kDa与本实验中所有寄生虫感染的动物和患者均有交叉反应。结论 65、58、53 kDa蛋白为旋毛虫和卫氏并殖吸虫的共同抗原,108kDa蛋白为旋毛虫和华支睾吸虫的共同抗原,而53 kDa蛋白为这3种寄生虫的共同抗原。     

建立和评价ELISA法检测血清和唾液中旋毛虫IgG抗体的研究

目的 建立检测血清和唾液中旋毛虫抗体的酶联免疫吸附试验(ELISA)方法.方法 应用方阵滴定法,筛选适宜的旋毛虫抗原(肌肉幼虫可溶性抗原、肌肉幼虫排泄分泌抗原、成虫可溶性抗原、成虫排泄分泌抗原)浓度、血清和唾液稀释度、辣根过氧化物酶标记的山羊抗兔、山羊抗人IgG抗体稀释度.共有20份旋毛虫感染兔、10份旋毛虫病患者血清和唾液用于这4种抗原的敏感性试验,20份健康兔与38份其他寄生虫感染兔和患者的血清和唾液用于这4种抗原的特异性试验.结果 这4种抗原适宜包被浓度依次为8.0 μg/ml、6.0 μg/ml、10.0 μg/ml、9.0 μg/ml.适宜的血清稀释度依次为1:100、1:200、1:50、1:200,唾液均用原液.适宜的山羊抗兔、山羊抗人IgG稀释度分别为1:2 500和l:2 000.这4种抗原检测旋毛虫感染兔血清和唾液的敏感性分别为100%和80%~100%,检测旋毛虫病患者血清和唾液的敏感性分别为100%和60%~80%;检测血清和唾液的特异性依次为81.03%、89.65%、77.59%、82.76%和93.10%、96.55%、89.65%、91.35%.结论 建立了检测兔和人血清及唾液中旋毛虫lgG抗体的ELISA方法.当采集血清标本有困难时,可将唾液替代血清用于检测旋毛虫病.     

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.     

旋毛虫Ts21重组蛋白的免疫诊断价值及免疫保护作用的研究

目的 探讨旋毛虫Ts21重组蛋白的免疫诊断价值及免疫保护作用。 方法 应用旋毛虫Ts21重组蛋白ELISA（Ts21-LISA）与肌幼虫ES抗原ELISA（ES-LISA）对旋毛虫病与其他寄生虫病患者血清及5种旋毛虫（T1、T2、T3、T4和T7）感染小鼠血清进行检测,并观察不同剂量旋毛虫感染小鼠后不同时间的血清抗体水平。将Ts21重组蛋白皮下注射免疫小鼠（20 μg/只,免疫3次,每次间隔10 d）,末次免疫后10 d,每只小鼠用300条旋毛虫肌幼虫经口攻击感染,3.5 d和42 d 后剖杀,观察肠道成虫与肌幼虫数并计算减虫率。 结果 Ts21-LISA检测旋毛虫病、并殖吸虫病、囊尾蚴病及棘球蚴病患者血清的抗体阳性率分别为94.7%（18/19）、15.8%（3/19）、9.1%（1/11）和7.7%（1/13）,与血吸虫病、华支睾吸虫病患者血清及健康人血清无交叉反应;Ts21重组蛋白与ES抗原ELISA检测旋毛虫病患者血清抗体的敏感性与特异性差异均无统计学意义（χ²=0,P＞0.05;χ²=0.358,P＞0.05）。Ts21重组蛋白与ES抗原检测T1感染小鼠血清的敏感性差异无统计学意义（χ²=0.104,P＞0.05）,与T2、T3、T4、T7感染小鼠血清的交叉反应率明显低于ES抗原（χ²=17.069,P＜0.05）。小鼠感染300条旋毛虫后4 周,应用Ts21-LISA检测的血清抗体阳性率为100%（10/10）;小鼠感染5条旋毛虫后6周,血清抗体阳性率为100%（10/10）。Ts21重组蛋白免疫小鼠用旋毛虫攻击感染后3.5 d和42 d,肠道成虫与肌幼虫减虫率分别为42.71%和49.8%。 结论 Ts21重组蛋白可用于旋毛虫病的血清学检测,但不能忽视与并殖吸虫病、囊尾蚴病及棘球蚴病患者血清的交叉反应。     

旋毛虫抗原基因Ts43原核表达及重组蛋白鉴定

目的原核表达旋毛虫相对分子质量(Mr)43 000抗原基因(Ts43)并对重组蛋白进行抗原性鉴定。方法将旋毛虫抗原基因Ts43克隆入原核表达载体pET30a(+),构建重组表达质粒pET30a(+)-Ts43,经测序分析正确后转化大肠埃希菌BL21,以异丙基-β-D硫代半乳糖苷(IPTG)诱导表达。十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)和蛋白质印迹分析(Western blotting analysis)鉴定重组蛋白的抗原性。结果SDS-PAGE结果显示表达产物为Mr 41 000的重组融合蛋白,IPTG诱导4 h时表达量最大,薄层凝胶光密度扫描显示表达的融合蛋白占菌体蛋白总量的14.7%。Western blotting结果显示该重组蛋白可被旋毛虫、乡土旋毛虫及纳氏旋毛虫感染小鼠血清及旋毛虫病患者血清识别,与人芽囊原虫、微小隐孢子虫感染小鼠和正常小鼠血清和正常人血清无交叉反应,但与棘球蚴病、囊尾蚴病、日本血吸虫病、并殖吸虫病及华支睾吸虫病患者血清均有交叉反应。结论旋毛虫Ts43基因的重组蛋白具有较好的抗原性,但与某些寄生虫病患者血清有交叉反应。     

Inhibition of neutrophil oxidative metabolism by trichinellosis patient sera. Parasite origin or host induction?

The presence of sera factors able to inhibit both neutrophil chemotaxis and phagocytosis was observed in all patients studied at two months from infection caused by Trichinella britovi and in most of them after one year. Human neutrophils with eosinophils are able to kill T. spiralis newborn larvae in an ADCC system and their major cytotoxic mechanism is oxidative metabolism products. We evaluated the effect of trichinellosis sera on neutrophil oxidative burst to determine if neutrophils are affected by circulating factors during infection. Cells were incubated with sera from trichinellosis patients. Basal or stimulated Superoxide Anion (SA) production and chemilumines-cence in response to different stimulation (PMA, f-MLP, opsonized yeasts) of neutrophils incubated with trichinellosis sera were evaluated and compared with those of cells incubated with control sera. The results show that basal SA production was inhibited by 66% of sera and stimulated by 11%. On the contrary f-MLP stimulated production was significantly increased by 22% sera, and inhibited by none. Chemiluminescence in response to f-MLP or PMA was inhibited by 46 and 80% of sera, respectively. These results show that trichinellosis sera can modulate not only SA production but also other steps of the oxidative burst, irrespective of the stimulating agent, so suggesting that different neutrophil activation pathways are affected. Increased IL-2 levels observed in most of the sera did not correlate with the inhibiting capacity of sera. The hypothesis of a parasite origin of the inhibiting factors is discussed in the light of host-parasite relationship.,     

旋毛虫幼虫排泄分泌抗原用于诊断人旋毛虫病的可行性探讨

作者将自行分离制备的旋毛虫肌肉期幼虫２４小时排泄分泌抗原，用间接ＥＬＩＳＡ共检测３４份旋毛虫病人血清，３２份为阳性，阳性率９４％．而８２份正常人血清均为阴性反应。且不与蛔虫病人、囊虫病人血清发生交叉反应，但与肺吸虫及血吸虫病人血清发生交叉反应。经用ＳＤＳ－ＰＡＧＥ及铵银染色后显示，该抗原含有１１种蛋白组份，分子量介于９６ｋＤ－１７．６ｋＤ之间。有３条主带，分子量分别为４０、４８、５３ｋＤ。酶联免疫印迹试验表明旋毛虫病人血清能特异识别分子量为４８ｋＤ蛋白。而肺吸虫及血吸虫病人血清所能识别的区带均小于４０ｋＤ。该结果表明４８ｋＤ蛋白抗原组分在人旋毛虫病上具有潜在诊断价值，而酶联免疫印迹试验不失为一种可行的人旋毛虫病的诊断方法。     

旋毛虫DNA疫苗在中国仓鼠卵巢细胞中的表达

目的　观察编码旋毛虫相对分子质量(Mr)31000抗原的DNA疫苗(重组真核表达质粒pcDNA3 TspE1)在中国仓鼠卵巢(CHO)细胞中的体外表达 ,并分析其表达产物的抗原性。　方法　通过用阳离子脂质体Lipofectamine2000将重组质粒pcDNA3 TspE1转染CHO细胞,G418筛选阳性克隆,用逆转录聚合酶链反应(RT PCR)、间接荧光抗体试验(IFAT)、十二烷基硫酸钠 聚丙烯酰胺凝胶电泳(SDSPAGE)和蛋白质印迹法(Westernblotting)对表达产物进行鉴定。　结果　RT PCR结果显示,pcDNA3 TspE1转染的CHO细胞在876bp处有一条带,而用空质粒pcDNA3转染的CHO细胞未出现条带,表明pcDNA3 TspE1转染细胞中有TspE1基因转录。IFAT结果显示,pcDNA3 TspE1转染的CHO细胞与重组融合蛋白免疫小鼠血清反应呈现亮绿色荧光 ,而pcDNA3转染的CHO细胞及未转染细胞呈现橘黄色。Westernblotting显示在pcDNA3 TspE1转染的CHO细胞培养液中存在有一Mr约31000的蛋白带 ,且该条带能被重组融合蛋白免疫小鼠血清、旋毛虫肌幼虫可溶性抗原免疫兔血清、感染旋毛虫的小鼠及旋毛虫病患者血清识别。　结论　重组质粒pcDNA3 TspE1可转染CHO细胞,旋毛虫TspE1基因可在转染的CHO细胞中表达,表达蛋白能分泌到细胞培养上清中且具有旋毛虫     

Detection of Trichinella spiralis antigens in urine of men and animals

The practical inability to diagnose Trichinella spiralis antibodies in man before day 20 post infection (dpi) has stimulated interest in the development of immunodiagnostic test to detect circulating antigens. Our previous experience showed that soon after infection immune complexes as well as uncomplexed parasite antigens in sera of infected rats could be detected. To diagnose the presence of antigen in urine, double sandwich-capture ELISA was applied using a peroxidase-conjugated rabbit immunoglobulin to T. spiralis larval antigens. The plates were coated with metabolic (AES) or somatic (AS) larval antigens. Mice were infected with 500 T. spiralis larvae. The urine samples from experimentally infected mice taken from 1 to 41 dpi. and the urine samples from patients of the Clinical Hospital in Bia?ystok taken from 3 to 120 dpi were examined. Before testing, the urine samples were heated for 6 min. at 100 degrees C and centrifuged for 6 min. at 5000 g, supernatants were used in ELISA. The presence of T. spiralis antigens in mice urine samples was detected between 6-26 days post infection (dpi) using double sandwich-capture ELISA. All samples taken later were negative as samples taken from uninfected mice. 3 from 9 human urine samples taken 3-10 dpi were positive, the remaining samples taken 3-10 and 10-30 dpi showed values near to "cut-off". In both mice and human urine samples the higher level of antigens was detected in ELISA when somatic larval antigen was used. The T. spiralis antigens were present in urine of infected men and mice in the first phase of infection.     

夹心免疫-PCR检测旋毛虫循环抗原的研究(英文)

目的建立以多抗为捕获抗体和单抗为检测抗体的夹心免疫-PCR检测旋毛虫循环抗原。方法利用杂交瘤技术制备抗旋毛虫单抗;旋毛虫抗原免疫家兔,分离纯化兔血清,制备兔抗旋毛虫多抗。多抗作为捕获抗体包被酶标板,单抗为检测抗体,选择适宜多抗和单抗浓度,建立夹心ELISA方法,再利用亲和素和生物素的高结合力连接起标记了生物素的抗体和DNA片段,将抗原抗体特异反应的免疫技术同无限扩增DNA片段的基因检测技术结合,利用PCR反应对DNA片段的扩增能力,提高检测灵敏度。结果制备了兔抗旋毛虫多抗,间接ELISA法筛选出与多种寄生虫抗原无交叉反应的单抗F4C6,夹心ELISA检测旋毛虫抗原最低浓度为0.05μg/ml,免疫PCR方法检测最低浓度为0.1ng/ml。结论首次建立夹心免疫-PCR检测旋毛虫抗原的方法,检测旋毛虫抗原的灵敏度高于传统ELISA方法104倍。     

The estimation of different ELISA procedures for serodiagnosis of human trichinellosis

INTRODUCTION: The most important confirmative diagnostic test for trichinellosis is the presence of the muscle larvae in a tissue biopsy but this direct method has a low sensitivity of light and moderate infections. The aim of presented study was to compare the usefulness of the results obtained by three ELISA procedures for Trichinella spp. diagnosis in human outbreaks. MATERIALS AND METHODS: All sera (cases and controls) were tested for anti-Trichinella antibodies (immunoglobulin G) using commercially available Novatec KIT and two other ELISA procedures based on excretory-secretory (ES) antigens on Trichinella spiralis muscle larvae. The main differences in ELISA procedures were: the protein concentration in antigen, dilution of human serum samples, conjugate and the time of conjugate incubation. Additional differences were noticed in ES antigen preparation procedures as well as in T. spiralis isolates used in these procedures. Serum samples were obtained from 22 symptomatical patients from Poznafi region (West Poland), geographic area where human outbreak had occurred. Control serum samples were obtained from 20 patients from an open population from a non endemic trichinellosis area. RESULTS: The results were analyzed in terms of both: statistical and epidemiological point of view. Linear regression analysis and correlations coefficient r between OD values of total 22 patients obtained in three ELISA procedures were positive and high statistically significant. Three ELISA procedures revealed different cut-off values and positivity rates for outbreak. However, the majority of positive samples were found as positive in three procedures, but some of them were positive in two or one procedure only. These individual variability in sera reactivity observed in three ELISA procedures could be very important from epidemiological point of view.     

旋毛虫抗原基因Ts21的原核表达与重组蛋白鉴定

目的 原核表达旋毛虫相对分子质量（Mr）21 000抗原基因（Ts21）并对重组蛋白进行纯化和抗原性鉴定。 方法 将旋毛虫抗原基因Ts21亚克隆入原核表达载体pMAL-c2X，构建重组表达质粒pMAL-c2X-Ts21，经酶切鉴定正确后转化大肠埃希菌TB1，以异丙基-β-D硫代半乳糖苷（IPTG）诱导表达。亲和层析法纯化表达产物。应用十二烷基磺酸钠?鄄聚丙烯酰胺凝胶电泳（SDS-PAGE）和蛋白质印迹（Western blotting）分析鉴定重组蛋白的抗原性。将重组蛋白免疫小鼠制备免疫血清，ELISA检测抗体滴度，免疫荧光检测（IFA）确定Ts21蛋白在肌幼虫体内的分布。 结果 SDS-PAGE结果显示，表达产物为Mr 63 500的重组融合蛋白，IPTG诱导4 h后表达量最大，薄层凝胶光密度扫描显示表达的融合蛋白占菌体蛋白总量的18.2%。Western blotting结果显示该重组蛋白可被旋毛虫、纳氏旋毛虫感染小鼠血清及旋毛虫病患者血清识别，但不能被乡土旋毛虫、布氏旋毛虫及伪旋毛虫感染小鼠血清识别；与钩虫病、囊尾蚴病、日本血吸虫病患者血清无交叉反应，但与并殖吸虫病、华支睾吸虫病及棘球蚴病患者血清有交叉反应。重组蛋白免疫小鼠可产生高滴度的血清抗体，IFA显示Ts21蛋白主要分布于肌幼虫体壁。 结论 成功制备了旋毛虫Ts21基因的重组蛋白，该蛋白具有较好的抗原性。     

Detection of IgG antibodies of Brugian filariasis with crude male and female antigens of Dirofilaria immitis

Crude antigens from male and female Dirofilaria immitis were used to detect antibody to Brugian filariasis in humans by indirect ELISA. Both antigens were tested with 42 cases of Brugian filariasis, 131 cases of 20 heterologous infections and 35 healthy controls. The results--using male and female antigens--showed sensitivity of 88.1% and 88.1%, and specificities of 64.1% and 51.8%, respectively. Cross-reaction from other helminthic infections using crude male antigen gave false-positives with 48 sera from 13 heterologous diseases at the threshold value of 0.180, while the female antigen gave 63 sera from 15 diseases, at 0.309. Serum antibodies from patients with other helminthic infections--gnathostomiasis, strongyloidiasis, hookworm infections, trichinellosis, capillariasis, angiostrongyliasis, ascariasis, trichuriasis, toxocariasis, neurocysticercosis, cystic echinococcosis, taeniasis and opisthorchiasis--resulted in false-positives with both male and female antigens. One each of sparganosis and paragonimiasis heterotremus sera cross-reacted with only crude female antigen and their OD values were close to the threshold value. Although crude male antigen showed better specificity than crude female antigen, both female and male worms are sources of antigens needed for further purification. This study provides baseline data for further serodiagnosis of Brugian filariasis using dirofilaria antigen.     

Activity of specific IgG, IgM and IgE antibodies in human trichinellosis.

The activity of IgG, IgM and IgE antibodies to somatic antigen of Trichinella spiralis in the sera of patients with trichinellosis at various intervals after infection was examined by means of ELISA. Mathematical analysis of the dose-response curves was used. Elevated level of IgG and IgM antibodies of relatively high avidity and of rather low IgE avidity was documented. Amount or avidity of IgG antibodies was found to be most useful for the diagnosis of trichinellosis (85% positive results in patients' sera). The isotype of IgM avidity constitutes a better diagnostic value than the amount of it (60% and 35% of positive results, respectively).     

旋毛虫氨基肽酶的表达及其血清学诊断价值的研究

目的构建旋毛虫氨基肽酶（TsAP）基因重组质粒,表达重组TsAP蛋白,评价该蛋白的血清学诊断价值。方法通过RT-PCR扩增TsAP基因。构建重组质粒pGEX-6p-1-TsAP,测序及酶切鉴定后转化E．coliBL21,用异丙基-G-D-硫代半乳糖苷（IPTG）诱导,表达产物经GSTSefinoseResin（BBI）亲和层析纯化后应用SDS-PAGE和Westernblot进行鉴定。应用旋毛虫重组rTsAP蛋白EusA（rTsAP-ELISA）对旋毛虫感染小鼠血清进行检测,观察旋毛虫感染小鼠后不同时间的血清抗体阳性率,并与旋毛虫肌幼虫ES抗原ELISA（ES-EIJIsA）的检测结果进行比较。结果构建的重组表达载体pGEX-6p-1-TsAP能表达TsAP蛋白。SDS-PAGE结果显示,rTsAP的分子质量单位约为80ku,以IPTG诱导4h后表达量最大。rTsAP-ELISA及ES-ELIS对旋毛虫感染小鼠血清的抗体检出率均为100％（40／40）,与曼氏裂头蚴、弓形虫感染小鼠及正常小鼠血清均无交叉反应,与日本血吸虫感染小鼠血清的交叉反应率分别为93．75％（15／16）和50．00％（8／16）（P〈0．05）。rTsAP-ELISA与ES-ELISA对旋毛虫感染2周的小鼠血清抗体检出率分别为50．00％（11／22）和81.82（18／22）,差异无统计学意义（P〈0．05）,至感染后6周抗体检出率均达100％。结论重组TsAP蛋白具有良好的反应原性,但与日本血吸虫感染小鼠血清有较高的交叉反应。