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1.
An enzyme-linked immunosorbent assay (ELISA) for the detection of antibody in pigs infected with a possibly new species of Taenia isolated in Taiwan is described. The test antigen ThFAS was fractionated from the cyst fluod of a heterologous cestode Taenia hydatigena. In lightly infected pigs ( 4 recovered cysts at necropsy 17 weeks post-inoculation), antibody was detected as early as 3 weeks post-inoculation. In more heavily infected pigs (6–72 recovered cysts at necropsy 32 weeks post-inoculation), antibody was still detectable at the time of necropsy. Cysterci were found only in the livers of the infected pigs. This ELISA should be highly useful for detecting infection of pigs with this larval cestode in regions where the presence of Taenia solium is unlikely.  相似文献   

2.
Serum antibody responses in sheep naturally or experimentally infected with Echinococcus granulosus and/or other larval cestodes were examined using an enzyme-linked immunosorbent assay (ELISA) with various antigens prepared from sheep hydatid cyst fluid ( SHCF ). Serum donors included: sheep experimentally infected with E. granulosus and their age-matched non-infected controls; sheep experimentally infected with other helminth parasites; sheep naturally infected with E. granulosus both from Tasmania and the Australian mainland; sheep from Tasmania naturally infected with larval cestodes other than E. granulosus; and naturally reared sheep completely free from infection with larval cestodes. Attempts were made to eliminate serological reactions which were not specific for E. granulosus by using a series of antibody affinity chromatography steps to deplete crude SHCF antigen; these included adsorption with a monoclonal antibody, 3EgH 29-2, removal of host IgG using rabbit anti-sheep IgG antibody, and removal of antigens which bound non-specifically to normal sheep immunoglobulin. The final affinity-depleted antigen product was designated AD SHCF . Specific serological reactivity in infected sheep was very low. Affinity depletion of SHCF using 3EgH 29-2 did not appear to increase the specificity of serological diagnosis of E. granulosus infection when experimentally infected sheep were compared with their non-infected controls provided the latter were age-matched with experimental animals. The other affinity adsorption steps significantly reduced non-specific background binding to antigen by normal sheep serum. Despite this reduction in background in the ELISA, only low levels of antibody could be detected in naturally-infected sheep.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
An enzyme-linked immunosorbent assay (ELISA) for the detection of antibody in pigs infected with a possibly new species of Taenia isolated in Taiwan is described. The test antigen ThFAS was fractionated from the cyst fluod of a heterologous cestode Taenia hydatigena. In lightly infected pigs ( 4 recovered cysts at necropsy 17 weeks post-inoculation), antibody was detected as early as 3 weeks post-inoculation. In more heavily infected pigs (6–72 recovered cysts at necropsy 32 weeks post-inoculation), antibody was still detectable at the time of necropsy. Cysterci were found only in the livers of the infected pigs. This ELISA should be highly useful for detecting infection of pigs with this larval cestode in regions where the presence of Taenia solium is unlikely.  相似文献   

4.
Three-year-old, non-lactating and non-pregnant Merino ewes, raised on pasture under a program of strategic treatment with anthelmintic and found to be extremely resistant to "trickle" infection with Haemonchus contortus, were given single-dose infections with either H. contortus or Trichostrongylus colubriformis or both species together. The purpose was to ascertain the intensity of protective immunity against the 2 parasites in sheep with immunity acquired from a presumably slight exposure to infection. To provide a criterion, some infected ewes were immunosuppressed with corticosteroid, dexamethasone. Untreated ewes were extremely resistant to challenge infection with either 15,000 or 150,000 H. contortus or 15,000 T. colubriformis. Surprisingly, when mixed infection was given, egg counts for H. contortus were significantly elevated compared with infection by that species alone. Antibody to antigens from infective larval and adult H. contortus was measured in serum by enzyme-linked-immunosorbent assay (ELISA) during the course of infection. Serum titres against larval antigens were significantly depressed when infections with either H. contortus or T. colubriformis were permitted by immunosuppression with dexamethasone, whereas those against adult antigen were depressed when infection with T. colubriformis was permitted.  相似文献   

5.
为了观察绵羊用多头蚴抗原免疫及感染后的抗体消长规律,为羊脑多头蚴病的免疫预防和免疫诊断提供依据,本试验应用多头蚴原头节可溶性抗原、囊壁可溶性抗原、囊液粗抗原致敏绵羊红细胞对绵羊免疫3次及虫卵攻击感染后的血清抗体进行间接血凝试验(IHA)检测。结果表明,原头节抗原免疫组、囊壁抗原免疫组、囊液抗原免疫组及原头节ES抗原免疫组在首次免疫后1周,抗体滴度迅速升高,第3次免疫后1周达到峰值,虫卵感染后开始下降,到感染后30周接近正常水平。多头蚴3种抗原对同种抗原免疫组血清检测敏感性、特异性优于其它抗原,原头节免疫组、囊壁免疫组、囊液免疫组抗体水平明显高于原头节ES抗原免疫组。  相似文献   

6.
A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae. The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4+ T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by CD8/IFN-γ double positive cells. γδ T-cells were not expanded at any time point analysed. IFNγ+ T cells disappear 60 days after infection, suggesting that antigen specific IFNγ+ T cells, mainly detected in the early phase of the disease, could be useful to understand the role of cell-mediated immunity during M. agalactiae infection.  相似文献   

7.
Groups of dogs reared free of both nematodes and cestodes were infected with Taenia hydatigena, Taenia pisiformis or Echinococcus granulosus. After infections with the Taenia spp became patent, dogs were purged to remove the worms. They were later reinfected and the second infections again removed by purging after patency. A group of 3 uninfected worm free dogs was kept as age-matched controls. The dogs were bled at intervals of 5 days and their serums tested for antibodies using the enzyme-linked immunosorbent assay (ELISA) with excretory/secretory (ES) antigens collected during in vitro incubation of evaginated scoleces (scolex ES antigen) and oncosphere antigens. Antibodies to scolex ES antigen were detected by 3 weeks after infection with each cestode species whereas antibodies to oncosphere antigen were not detected until about one week after eggs were found in the faeces of the infected dogs. Antibody responses to both oncosphere and scolex ES antigens decreased rapidly following removal of the worms by purging. Uninfected control dogs were invariably negative to both oncospheral and scolex ES antigens. There were cross-reactions between the serums from dogs infected with T. pisiformis and T. hydatigena when tested with scolex ES antigens, but oncospheral antigens showed a high degree of species specificity. Scolex ES antigens from E. granulosus were compared with those prepared from T. hydatigena and T. pisiformis for their ability to discriminate between antibodies in serums collected from dogs 31 and 32 days after infection with 100,000 protoscoleces of E. granulosus or dogs infected with Taenia spp.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
An antigen was prepared from purified sheep hydatid-cyst fluid by gelfiltration on Sephadex G-200 followed by chromatography on DEAE-cellulose. In each case the first-peak material was used. This antigen, which migrated cathodically, was concentrated and used in immunoelectrophoretic analyses of 4X concentrated sera from sheep experimentally and naturally infected with Echinococcus granulosus and from uninfected sheep. Of 34 sheep with E. granulosus infection 31 were positive with the cathodic antigen while of 85 sheep without E. granulosus 8 were (falsely) positive. Many false positives appeared to be associated with heavy infections of Taenia ovis or T. hydatigena larvae. The “arc 5” immunoelectrophoresis test, which is the most specific immuno-diagnostic test for echinococcus infection in humans, was not able to specifically identify E. granulosus infections in sheep.  相似文献   

9.
The serological cross reactions between Mycoplasma conjunctivae, the etiological agent of infectious keratoconjunctivitis (IKC), and the antigenetically and phylogenetically closely related Mycoplasma ovipneumoniae, which is often found in sheep, were analysed. Cross reacting antigens were identified using sera from sheep with IKC and from sheep of herds known to be free of IKC, as well as rabbit hyperimmune serum specific to the two Mycoplasma species. Cross reactions were predominantly due to the strongly antigenic proteins of 42 kDa and 83 kDa. Serospecific antigens of M. conjunctivae could be separated from cross-reacting antigens by the extraction of Tween 20-soluble membrane proteins. The Tween 20-extracted proteins of the M. conjunctivae strain HRC/581T were used for the development of an indirect ELISA test. This ELISA test was shown to be a useful serological method for the diagnosis of M. conjunctivae infections and to identify infected sheep herds.  相似文献   

10.
Mesocestoides cestode infections in dogs are well known for causing severe peritonitis with larvae or larval fragments (metacestodes, tetrathyridia, or calcareous corpuscles) frequently observed cytologically in peritoneal fluid samples. This case report describes the cytologic and clinical features of 2 dogs infected with cestode larvae, with one case confirmed and the other presumed to be Mesocestoides sp. In these 2 unusual cases, cestode larvae or larval fragments were found in fine‐needle aspirates of the liver and a mesenteric lymph node, but no organisms were found in peritoneal fluid samples. The data presented in this report indicate that clinical pathologists should not rule out Mesocestoides sp cestodiasis based on the absence of larvae in peritoneal fluid samples from dogs.  相似文献   

11.
A method to assess the expansion of antigen-specific intracellular IFN-γ positive T cell subsets during the infection will be helpful for a better understanding of mycoplasmal infections physiopathology in the sheep. We analysed the percentage of antigen-specific lymphocytes positive for intracellular IFN-γ during the infection of sheep with Mycoplasma agalactiae by culturing peripheral blood mononuclear cells of infected or uninfected animals with irradiated M. agalactiae. The expansion of antigen-specific IFN-γ positive lymphocytes in infected sheep was initially sustained by CD4+ T cells at day 15 after infection, when antigen specific IgG start to be detectable, followed by CD8/IFN-γ double positive cells. γδ T-cells were not expanded at any time point analysed. IFNγ+ T cells disappear 60 days after infection, suggesting that antigen specific IFNγ+ T cells, mainly detected in the early phase of the disease, could be useful to understand the role of cell-mediated immunity during M. agalactiae infection.  相似文献   

12.
Polysaccharide antigens were obtained from either the secretions produced during in vitro cultivation of Echinococcus granulosus protoscoleces or from mouse hydatid cyst membranes by phenol extraction. When either of these antigens was used in an enzyme-linked immunosorbent assay antibody activities were detected in sera from sheep infected 27 or more weeks earlier with at least 100 E granulosus eggs. These antibody responses were significantly higher (P less than 0.05) than those of sheep infected with Taenia hydatigena or T ovis and tested with the E granulosus antigens. Very high cross-reacting antibody responses in sera from sheep recently infected with T hydatigena were only detected with the protoscoleces secretions antigen. Neither antigen was sufficiently sensitive or specific for serodiagnostic use. However, when sera were first tested with one antigen and then with the other, and only sera that were positive in both tests were regarded as positive, the overall sensitivity and specificity of this two antigen method increased to about 80 per cent.  相似文献   

13.
Immunodiagnostic confirmation of cystic human hydatidosis is frequently required before surgical intervention or of chemotherapy. However, it remains inadequate to detect specific antibodies or antigens in some confirmed cases of echinococcosis. This study was carried out to investigate the accuracy of three different immunodiagnostic tests for detection of specific circulating antigens or antibodies in the serum and urine of 13 experimentally infected sheep. For this purpose, Echinococcus granulosus were collected from small intestine of experimentally infected dogs, and 2000 taenid eggs were orally administered to each of the 13 sheep. There were six other sheep, which were kept as the control group. Biweekly serum and urine samples were collected from all the sheep for 4 months after infection. The sera were subjected to indirect hemagglutination test and the concentrated urine samples were subjected to coagglutination and counter immunoelectrophoresis tests. The results revealed that the sensitivity of these tests in detecting the hydatid antigens in the urine or antihydatid antibodies in the serum of the infected sheep reached their maximum in 12th and 13th week after infection; then it decreased in the following weeks. Examination of the non-infected sheep samples throughout the experiment showed that the aforesaid findings were specific only to the infected sheep. It seems that the appearance of specific hydatid antigen in urine and its antibodies in the serum were simultaneous. Although these tests are highly specific, false negative outcomes were encountered in their detection of cystic echinococcosis. In general, it seems rational to establish some series of diagnostic procedures in order to reveal antibodies and antigen of metacestode in serum and urine of the patients.  相似文献   

14.
Lymphoproliferative response (LPR) was studied in 19 lambs orally infected (Group I) with Mycobacterium avium subsp. paratuberculosis (MAP) with in vitro lymphocyte stimulation test using MTT dye reduction assay. The non-specific LPR against Con A and specific LPR against sonicated antigen and johnin PPD (purified protein derivatives) were estimated on preinfection (0 day) and various days postinfection period (15 to 330 dpi) in the animals, which were classified according to histological and bacteriological evidence of paratuberculosis infection. Of the two antigens used, johnin PPD was found to be superior in terms of consistency and uniformity of response over an observation period of about a year. Significantly (P < 0.05) higher LPR were observed in the infected sheep during postinfection period, as compared with preinfection values and values from uninfected control sheep. It was evident from the present study that the LPR in histologically infected animals fluctuated during the long course of infection and had a definite relationship with the gut pathology and the mycobacterial load. The LPR were stronger but variable in sheep with grades 1, 2 and 3 lesions (paucibacillary) and increased progressively from 30 dpi onwards. The sheep with the advanced lesions (grade 4, multibacillary) showed progressive decline in LPR till 120 dpi after initial stronger response at 30 dpi. Most of the animals were detected by LPR before initiation of faecal shedding of MAP. The results suggested that repeated testing was required while screening an infected flock for detecting most of the positive animals.  相似文献   

15.
The procedure of countercurrent immunoelectrophoresis in the diagnosis of Taenia hydatigena cysticercosis in goats was carried out for antemortem diagnosis of T. hydatigena cysticercosis in experimentally and naturally infected goats. The antigens of cyst fluid, scolex and membrane of T. hydatigena metacestodes were purified and compared. The sensitivity of the test in experimentally and naturally infected goats was 57.1 and 52.5%, respectively, whereas its specificity using antisera raised against T. solium cysticercosis, hydatid cyst and Fasciola gigantica was 66.7 and 83.4% with partially purified and fractionated antigens, respectively. Of all three antigens, the cyst fluid antigen was found to be most reactive. The test could be employed for antemortem diagnosis of T. hydatigena cysticercosis using purified antigen.  相似文献   

16.
为建立特异性和敏感性高的检验犬细粒棘球绦虫感染的方法。用细粒棘球绦虫(简称,Eg)成虫抗原分别免疫兔和绵羊,收集高免血清,纯化的高免抗体。依据抗体夹心ELISA工作原理,以兔抗体包被,检测感染Eg、不同犬带科绦虫的实验犬和空白犬粪样,绵羊抗体扑捉抗原,HRP标记兔抗绵羊IgG(1∶8 000)催化显色,用酶标仪测定OD 405nm吸光度,用以确定其特异性和敏感性。试验结果表明,敏感性为82.69%(43/52),特异性为85.88%(140/163);粪抗原在感染细粒棘球绦虫16d后可检出,最低抗原浓度为9.7ng/mL即犬感染5条成虫时可检测出阳性。该检测方法具有较好的特异性和灵敏性,为进一步研制检测细粒棘球绦虫虫体抗原ELISA检测试剂盒奠定了基础。  相似文献   

17.
A monoclonal antibody against a plasma membrane antigen of Trypanosoma rhodesiense was used for the detection of T brucei group-specific circulating antigen in 24 adult local dogs experimentally infected with T brucei brucei strain 8/18. Ten of the dogs were splenectomised and the remainder non-splenectomised (intact). Five dogs each from the splenectomised and intact groups were inoculated intravenously with try-panosomes. The infected dogs developed trypanosomiasis between days 4 and 8 after infection. The circulating antigens were detected as early as six days after infection and remained high until two weeks after treatment, when the circulating antigen declined. The detection of the antigens showed the existence of infection unlike the antibody test. The treatment of the infected dogs with diminazene aceturate (Berenil; Hoechst) at a dose of 7-0 mg/kg on day 21 after infection cleared all the parasites but elevated the circulating antigen levels. The antigen capture enzyme-linked immunosorbent assay is a useful diagnostic tool for complementing parasitological diagnosis, for detecting infection in the field and for ascertaining the efficacy of trypanocidal drugs.  相似文献   

18.
A variety of cells originating from different species, including man, can be infected with Borna disease (BD) virus. Two different virus infection-specific antigens with molecular weights of 24 kD and 35/38 kD (double band) could be demonstrated using antigen preparations from persistently infected cells and rat brains, and polyvalent antisera from naturally and experimentally infected animals. Three different monoclonal antibodies were selected. One was specific for the 24-kD protein and two others reacted with the 35/38-kD antigen. The 24- and 35/38-kD antigens could be monitored concomitantly with the appearance of newly synthesized infectious virus. Both antigens could be detected at the same time during the infection cycle, and showed identical distribution in the cell. Their relationship to one another and their possible function is discussed.  相似文献   

19.

Maedi visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) are a heterogeneous group of infectious agents affecting sheep and goats. Due to their natural cross-species infection they are referred to as small-ruminant lentiviruses (SRLV). Recently a new genetic cluster, highly divergent from MVV and CAEV was identified in the north-west part of Italy. A panel of genotype E specific antigens was developed and evaluated in flocks infected with B1 and E strains. The results clearly indicate that a strain specific antigen is required to correctly identify animals infected with different genotypes.

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20.
The suitability of an enzyme linked immunosorbent assay (ELISA) test with a 2.9 kDa Fasciola hepatica-recombinant protein (FhrAPS) for diagnosing early and current-ovine fasciolosis was analyzed, and compared to that obtained by using a direct ELISA for detecting F. hepatica-circulating FhES antigens and to the coprological sedimentation for fluke egg quantitation. Fourteen Gallega autochthonous breed sheep were experimentally infected with metacercariae by a trickle system (small repetitive infections) and divided into two groups: G-I represented a primary infection for 34 weeks; G-R, animals with primary infection and reinfected 18 w.a.p.i. Seven sheep were left uninfected as the control group (G-C). Serum IgG antibody values against the FhrAPS rose rapidly by 1st w.a.p.i. in all infected sheep. Antibody levels in those with primary infection (G-I, G-C) peaked at 10 weeks, diminishing slightly and levelling from 16 to 34 weeks. Those with primary infection reinfected at 18 weeks had a rebound effect with the highest values observed. Circulating F. hepatica-ES antigens were detected by the 1st w.a.p.i. in all infected groups peaking at 6 weeks, decreasing rapidly to uninfected control values by 10 weeks of infection. Faecal egg-output started 11 weeks after primary infection. An increase in the IgG antibody as well as antigen responses to the FhrAPS and to anti-FhES from the 18 w.a.p.i. was recorded in G-T and G-R after the challenge infection. Antibody levels remained high whereas antigenemia values diminished after 6 weeks. A positive significant correlation between the IgG response against the FhrAPS and the F. hepatica circulating antigens (r2 = 0.428, p = 0.001) was obtained. In conclusion, our standardized diagnostic ELISA for fasciolosis based on the detection of IgG responses to the FhrAPS would be a valuable tool to diagnosis early and current F. hepatica-infections in sheep.  相似文献   

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