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1.
Serum samples from 2000 cows, 3311 sheep and 638 goats from Iran were examined for antibodies to Toxoplasma gondii by use of the latex agglutination (LAT) and indirect hemagglutination tests (IHAT). Antibodies to T. gondii were found in 24.50% sheep and 19.25% of goats. Antibodies to T. gondii were not detected in cow sera by LAT and IHAT in 1:8 and 1:64 dilutions of bovine sera, respectively. Toxoplasma gondii was not found in tissues of 300 aborted fetuses from cows by direct microscopy and bioassay in mice.  相似文献   

2.
OBJECTIVE: To follow antibody responses measured by various serologic tests in pigs orally inoculated with low (< or = 10 oocysts) numbers of Toxoplasma gondii oocysts. ANIMALS: 24, 2- to 3-month-old pigs. PROCEDURE: Pigs (n = 42) were inoculated orally with 10 (14 pigs) or 1 (28 pigs) infective oocysts, and 6 pigs served as uninoculated controls. Blood (serum) samples were obtained at 1- to 3-week intervals until euthanasia. At necropsy, the brain, heart, and tongue of pigs were bioassayed in mice and cats for isolation of T gondii. Modified agglutination test (MAT), using whole, fixed tachyzoites and mercaptoethanol; latex agglutination test (LAT); indirect hemagglutination test (IHAT); Sabin-Feldman dye test (DT); and ELISA were used to evaluate serologic responses to T gondii. RESULTS: T gondii was isolated from tissues of 13 of 14 pigs each fed 10 oocysts, 17 of 28 pigs each fed 1 oocyst, and 0 of 6 control pigs. 29 of 30 T gondii-infected pigs developed antibodies when measured by MAT, DT, and ELISA; the 1 seronegative-infected pig had been fed 10 oocysts and was euthanatized 69 days after inoculation. LAT detected antibodies in 26 of 30 T gondii-infected pigs. IHAT detected antibodies in 11 T gondii-infected pigs. CONCLUSION: MAT, DT, and ELISA were more sensitive serologic assays than LAT and IHAT for detecting antibodies induced by low numbers of T gondii in pigs.  相似文献   

3.
The incidence of patent Toxocara canis infection as result of reactivation of somatic larvae with subsequent tracheal migration was investigated by faecal examination during 23 oestrous cycles of 15 bitches. Blood samples were collected for determination of total and differential leukocyte counts, prolactin concentration, and Toxocara titre. Five pregnant dogs were used as controls. In the cyclic dogs there were no alterations in white blood cell counts or prolactin concentration, in contrast with the pregnant dogs, in which both variables increased, starting 10 days after onset of the luteal phase. The difference was significant at day 40 and day 60 (both p < 0.005). No significant differences were observed in the number of eosinophils or in the Toxocara antibody titre. T. canis eggs were only found in the faeces of three 1-year-old, cyclic dogs at 1, 60, and 140 days, respectively, after the onset of the luteal phase. It is concluded that cyclic beagle bitches, in which prolactin levels increase in the second half of the luteal phase, are unlikely to be at higher risk for patent T. canis infection than in other phases.  相似文献   

4.
To determine the prevalence of the 3 primary clonal lineages of Toxoplasma gondii (strain types I, II, and III) in a potential food source of infection for humans, we analyzed 43 isolates of T. gondii that had been collected from pigs at an abattoir in Iowa. Parasites were harvested as in vitro-grown tachyzoites, and their genotypes were determined at the SAG1 and SAG2 loci. On the basis of the allele identified at the SAG2 locus, isolates were grouped into 1 of the 3 primary lineages. Type II strains were by far the most prevalent, accounting for 83.7% of the isolates. The type III genotype was identified in only 16.3% of the isolates. These prevalences differ significantly from a previous sampling of isolates from animals but are similar to the frequencies with which they occur in human disease cases. Similar to the previously characterized strain P89, strains P62 and P105 appeared to have recombinant genotypes. The type I genotype was not identified in the isolates from pigs although these strains have previously been shown to account for approximately 10-25% of toxoplasmosis cases in humans.  相似文献   

5.
This study aims to assess the possible strain-dependent variations in detection of Toxoplasma antigens and antibodies. The virulent RH strain or avirulent Beverley strain of T. gondii were injected into mice, intraperitoneally, and their antigens, antibodies and parasites were identified from the blood or tissues; liver, brain and spleen by ELISA, Western blot and PCR. In mice infected with RH strain, circulating antigens and parasitemia were first detected from 2 days after infection, and Toxoplasma DNA were found in the blood, liver, brain and spleen from 3 days after infection. It was impossible to detect specific IgM and IgG antibodies to T. gondii, and any specific band was not found by Western blot. In mice infected with Beverley strain, circulating antigens were detected between day 10 and day 35. The Toxoplasma DNA was found in the blood and liver from day 15 until day 60, and in the brain from day 20. But Toxoplasma DNA in the spleen were mainly detected between day 10 and day 30. The IgM antibodies were first appeared on day 10 post-infection, and were noted obviously increased between day 15 and 25. The IgG antibodies were first detected on day 15, and showed progressively increased titers. The antibody binding bands were specific according to infection period. Sera from mice infected with Beverley strain reacted mainly with the antigen of 27.5-kDa and 32.5-kDa. In conclusion, mice infected with RH strain revealed Toxoplasma antigens strongly, but not antibodies. However, mice infected with Beverley strain revealed both the Toxoplasma antigens and antibodies. The present results showed that immune responses are different between avirulent and virulent T. gondii.  相似文献   

6.
To determine the genotypes of Toxoplasma gondii strains associated with human toxoplasmosis, we developed a sensitive approach for typing parasites grown from clinical samples by short-term in vitro culture. A newly described nested PCR assay was capable of amplifying genomic DNA from as few as five parasites in the presence of host tissues. Typing was based on DNA polymorphisms at the SAG2 locus, encoding tachyzoite surface antigen p22. Restriction fragment length polymorphisms in PCR-amplified SAG2 products were used to classify strains into one of the three major lineages of T. gondii. This approach was successfully used to determine the genotypes of 68 of 72 samples that had been previously isolated from patients with congenital, cerebral, and disseminated toxoplasmosis. Type II strains of T. gondii were found in a majority of the samples, accounting for 55 (81%) of the 68 toxoplasmosis cases. In contrast, type I and III strains were found in only 7 (10%) and 6 (9%) of the 68 cases, respectively. The results of this study support the previous finding that type II strains are most often associated with human toxoplasmosis. Nested PCR analysis at the SAG2 locus provides rapid assignment of T. gondii to a specific genotype that should be useful in analyzing a variety of clinical samples.  相似文献   

7.
Most isolates of Toxoplasma gondii can be grouped into 3 genetic lineages. In the present study, 67 isolates of T. gondii were obtained by bioassay in mice inoculated with brains and hearts of 96 asymptomatic chickens from an area highly endemic to human infection in Rio de Janeiro, Brazil. Of the 48 isolates genotyped using the SAG2 locus, 34 (70%) were of type I and 13 (27%) were of type III. No isolate of type II was recovered. Isolates from 1 chicken contained a type I and type III mixed infection, indicating natural multiparasite infection in the same animal. Cats fed mice infected with 11 type I strains shed 19-535 million oocysts in their feces, indicating that type I isolates can circulate in the environment.  相似文献   

8.
Serum samples from 1,264 feral pigs from Ossabaw Island, Georgia were initially screened for antibodies to Toxoplasma gondii by the modified agglutination test (MAT) using whole-formalinized tachyzoites and mercaptoethanol. Seropositive samples were also tested by the Sabin-Feldman dye test, the latex agglutination test (LAT), and the indirect hemagglutination test (IHAT). Ossabaw Island is a remote, barrier island located southeast of Savannah, Georgia. Antibodies to T. gondii were found in 11 (0.9%) of 1,264 pigs. The antibody titers were 1:20 (1 pig), 1:80 (2 pigs), 1:160 (2 pigs), 1:320 (4 pigs), and 1:640 (2 pigs) by the MAT, and 1:8 (2 pigs), 1:16 (3 pigs), 1:32 (1 pig), 1:64 (2 pigs), 1:128 (1 pig), and > or = 1:256 (2 pigs) by the Sabin-Feldman dye test. By the LAT, 5 pigs had a titer of > or = 1:64 and by the IHAT all 11 pigs had a titer of < 1:64. Antibodies (MAT titer, > or = 1:25) were found in 31 (18.2%) of 170 feral pigs from mainland Georgia. This seroprevalence on the mainland was significantly higher (P < 0.0001) as compared on Ossabaw Island. The markedly low prevalence of T. gondii on Ossabaw Island was attributed to the virtual absence of cats on the Island; only 1 domestic cat was known to be present.  相似文献   

9.
Toxoplasma gondii is a zoonotic parasite of world-wide distribution. It is more or less endemic in all countries of the Middle East. In Jeddah Municipal abattoir, anti-Toxoplasma IgG was found to be 39% in sheep and 28% in goats as indicated by IHAT. On the other hand, anti-Toxoplasma IgG and IgM in butchers were 80% and 20% respectively, as indicated by the micro-ELISA. The risk of Toxoplasma transmission particularly, from meat inadequately cooked was discussed.  相似文献   

10.
We compared the seroprevalence of both Toxoplasma gondii and Trichinella spiralis in finishing pigs raised in different production systems in North Carolina, USA. Farms were either finishing sites using all-in/all-out management of buildings in multiple-site systems (14 farms) or farrow-to-finish systems using continuous-flow management of finishing barns or outdoor accommodation 14 farms). The two groups of herds differed with respect to several management variables. A total of 13 of 2238 samples (0.58%) were positive for antibodies to Toxoplasma gondii using the modified agglutination test. Of these, 12 were from 63 pigs sampled on a farm where finishing pigs were kept on pasture. Only one of 1752 (0.057%) samples from pigs kept in total confinement systems was seropositive. Only one pig of 2183 (0.046%) tested positive by ELISA for antibodies against T. spiralis. In this region, management practices in modern production systems appear to be adequate to virtually eliminate the risk of infection of finishing pigs with both T. gondii and T. spiralis.  相似文献   

11.
The Toxoplasma gondii rhoptry protein Rop2 was expressed in Escherichia coli as a fusion protein containing 44 kDa of the 55-kDa mature Rop2, supplied with six histidyl residues at the N-terminal end (Rop2196-561). Humoral response during Toxoplasma infection of humans was analyzed by immunoglobulin G (IgG), IgA, and IgM enzyme-linked immunosorbent assay with Rop2196-561 as the antigen substrate. The analyzed sera were divided according to T. gondii-specific serological tests (IgG, IgA, or IgM indirect immunofluorescence and IgA or IgM immunosorbent agglutination assay) as group A (IgG+ IgA- IgM-; n = 35), group B (IgG+ IgA+ IgM+; n = 21), group C (IgG+ IgA+ IgM-; n = 5), and group D (IgG+ IgA- IgM+; n = 16). Twenty-six T. gondii-seronegative sera from individuals with other infections were also included (group E). Anti-Rop2 IgG antibodies were detected in 82.8% of group A sera and in 97.6% of the sera with acute-phase marker immunoglobulins (groups B, C, and D). The percentage of IgA antibody reactivity against Rop2196-561 was 17.1% in group A, 50% in group D, and 80.8% in groups B and C. The percentage of IgM antibody reactivity was 0% in groups A and C and 62% in groups B and D. Sera from group E failed to show IgA, IgM, or IgG antibody reactivity. Since T. gondii Rop2 elicits a strong humoral response from an early stage of infection, it is suggested that recombinant Rop2196-561 would be suitable for use in diagnostic systems, in combination with other T. gondii antigens, to detect specific IgG, IgA, and IgM antibodies.  相似文献   

12.
Though Toxoplasma gondii can cause severe pathology in human, in most of the cases it produces only asymptomatic infection. So, it is important to dispose some methods capables to discriminate between acute and chronic infections. An indirect hemagglutination test (IHAT), dye test (DT) and complement fixation test (CFT) were performed in 647 sera from patients suspected of having toxoplasmosis infection. IHAT and DT titer > or = 4 and CFT > or = 5 were considered positive. Titers were classified as follows: low (4-16), median (64-512) and high (> or = 1000) for IHAT and DT. The pathologies for demanding these serological tests were: adenopathies (58), nephropathies (72), neuropathies (30), obstetrical problems (65), opthalmopathies (147), AIDS (237) and miscellaneous (37). Global positivity of 49.5% and 4.5% for IHAT/DT and CFT respectively were found. The positivity for the different groups were: adenopathies (48.3% and 13.8%), nephropathies (43.1% and 1.4%), neuropathies (26.7% and 3.3%), obstetrical problems (40.0% and 0.0%), ophthalmopathies (59.9% and 8.2%), AIDS (52.1% and 2.5%) and miscellaneous (40.5% and 2.7%) for IHAT/DT and CFT respectively. Low and median titers for IHAT/DT were found in 81.3% of cases. A high agreement in frequency of concordant and discordant titers of IHAT/DT and CFT, indicating a recent or acute infection was observed. This fact was more relevant in adenopathies, ophthalmopathies (uveitis) and AIDS groups.  相似文献   

13.
Wild and domestic animals from 3 geographic-climatologic areas in northern California were tested for antibodies against Toxoplasma gondii. A total of 2,796 serum samples representing 37 species of wild mammals, 35 species of wild birds, and 5 species of domestic animals were tested by the indirect hemagglutination test. Of 1,174 wild mammal serums tested, 10.8% were positive, which compared with 14.7% of the 1,221 domestic mammal serums. Of 229 wild carnivores tested, 45% were seropositive, including 69% of 86 bobcats, 28% of 58 coyotes, 48% of 25 raccoons, 27% of 26 gray foxes, 22% of 32 striped skunks, a civet cat, and a mink. Serologic evidence of infection was found in 38% of 47 rural domestic cats, but none of the 7 dogs tested was seropositive. Of 160 murid rodents (rats and house mice) in rural habitats, 4% were seropositive, which compared with 2% of 399 cricetine rodents (mostly deer mice) collected from wilderness habitats. Seven percent of 56 wild Artiodactyla (deer and feral pigs) were seropositive, which compared with 15% of 1,048 domestic sheep tested. Of 401 birds tested, 3.5% had antibodies against T gondii. The highest prevalence of antibodies among birds was in crows (14%). Toxoplasma was isolated from 1 raven, by mouse inoculation. In general, the highest prevalence of seropositive carnivores, rodents, and sheep was in the coastal region below 100 ft elevation, where the weather is cool and damp for much of the year. In the central valley the highest prevalence among sheep was in areas under irrigation. The prevalence of antibodies was lowest in the mountain areas, where climatologic extremes prevail at various seasons of the year.  相似文献   

14.
In this study, latex agglutination test (LAT) was used to detect sera anti-toxoplasma antibodies of Atayal aborigines and local animals in Nan-ao district, Ilan county and Jen-ai district, Nan-tou county as a measure of exposure to the Toxoplasma gondii. Out of 422 Atayal aborigines and 64 different animals were tested in Nan-ao district and 82 Atayal children in Jen-ai district were also screened, the positive rates for sera anti-toxoplasma antibodies were 21.8%, 17.2% and 15.9%, respectively. In Nan-ao district, neither were the positive rates significantly different in males (22.1%) and females (21.4%), nor in humans (21.8%) and dogs (19.6%) (P > 0.05). The seroprevalence in adults (28.3%) was significantly higher than that in children (18.7%) (P < 0.05), and the highest seropositive rate (38.1%) was in the age group 50-59 years and the lowest (7.7%) was in the age group 1-9 years. In general, the age pattern of prevalence is consistent with increasing duration of exposure to Toxoplasma gondii with age. For animals, the seropositive rate in dogs (19.6%) was also significantly higher than that in wild rats (7.7%) (P < 0.05). No significant difference in seropositive rate of Atayal children was observed between Nan-ao and Jen-ai districts (P > 0.05).  相似文献   

15.
Serum samples from 107 cervids were examined for Toxoplasma gondii antibodies using indirect hemagglutination (IHA), indirect immunofluorescence (IFA), enzyme linked immunosorbent assay (ELISA) and Dot-ELISA. Samples were obtained from 66 marsh deer (Blastocerus dichotomus) in the State of S?o Paulo (Brazil) and from 41 pampas deer (Ozotocerus bezoarticus) in the State of Goiás (Brazil). Antibodies to T. gondii were found in 23 (22%) of the deer, with 18 and 5 positive samples, respectively, for B. dichotomus and O. bezoarticus. The highest prevalence of T. gondii antibodies were young adults (32%), following by adults (27%) and fawns (13%). Only one serum sample (8%) from a newborn fawn was positive in the serological tests. The convenience of the Dot-ELISA test is obvious when compared with other serological tests for both laboratory or field surveys, mainly due to its features of practicability and reagent stability.  相似文献   

16.
The AA. investigated the frequency of antibodies against Toxoplasma gondii in 426 women with repeated abortions, perinatal mortality and malformed newborns. They showed on the whole a low incidence even if they demonstrated a high incidence (77.7%) of antibodies in women with malformed newborns. The meaning of the observations are briefly discussed.  相似文献   

17.
Sera from camels from Egypt were examined by the direct agglutination tests incorporating mercaptoethanol for antibodies to Neospora caninum and Toxoplasma gondii. Antibodies to N. caninum were found in 6 of 161 camels in titers of 1:40 (2 camels) and 1:80, 1:160, 1:640, and 1:1280 in 1 camel each, using N. caninum formalin preserved whole tachyzoites as antigen. Antibodies to T. gondii were found in 17.4% of 166 camels in titers of 1:25 (3 camels), 1:50 (18 camels). and > 1:500 (8 camels) using T. gondii tachyzoites. All 6 camels with N. caninum antibodies had no T. gondii antibodies in 1:4 dilution of serum, indicating specificity of the reaction. This is the first report of N. caninum prevalence in Egypt.  相似文献   

18.
The immunological reactivity of 19 operated cases of breast cancer (14 T1 2, 5T3) was investigated before and at 3-weekly intervals up to 12 weeks after radiotherapy by means of a large panel of techniques. The results were compared with two groups of identically-investigated patients, one consisting of 11 cases of cervical cancer (stage III), treated solely by irradiation and the other of 12 cases of cervical cancer (Stages I a and II b), treated by operation only. Before irradiation and in the non-irradiated group cellular immunity appeared to be more disturbed in cases of breast cancer than in cases of cervical carcinoma, as shown by the lowest number of lymphocytes, the lowest number of spontaneously-rosetting lymphocytes, the lowest percentage of DNCB sensitization in patients and the lowest percentage of Tuberculin-positive skin tests. In both types of carcinoma the humoral immunity appeared to be impaired, as apparent from the lowered immune response to tetanus vaccination. Other parameters of humoral immunity such as the immune globulin concentration, iso- and heteroagglutinine, the titre of measles antibodies or membrane fluorescence of lymphocytes showed no dinstinct trends during the investigation period. After irradiation a) inhibiting and b) stimulating influences were observed: a) The incidence and extent of the immune response to tetanus vaccination was further reduced and a distinct lymphopenic effect was observed. b) The incidence of positive skin tests with varidase, as well as the number of spontaneously-rosetting lymphocytes increased after the commencement of irradiation. Apart from the known sensitization with DNCB and skin tests with tuberculin, determination of the antitoxin titre before and after tetanus vaccination provided the most reliable results in regard to immunological reactivity in the investigated tumour patients.  相似文献   

19.
The effects of some parasitic infection (bilharziasis, toxocariasis and trichinosis) on the brain of experimentally infected mice were investigated. Eighty animals were classified into four groups, group I contained five non infected animals as a control group. The other groups each contained twenty-five mice infected with Schistosoma mansoni (group II), Toxocara canis (group III) and Trichinella spiralis (group IV). Each infected group was divided into two subgroups (a,b). Subgroup (a) left untreated and subgroups (b) treated by praziquantel (in group II) and mebendazole (in group III and IV). Histopathological and immunological examination using peroxidase antiperoxidase (PAP) technique and neurotransmitters estimation (nor-epinephrine, dopamine and serotonine) were carried. In the untreated animals, there were mild histopathological changes and mild antigenic deposition in subgroups (IIa and IIIa) and marked changes in subgroup (IVa). There were significant decrease in dopamine in subgroup (IIIa), not improved after treatment (subgroup IIIb) and significant decrease in nor-epinephrine and serotonine in subgroup (IVa) improved after treatment in subgroup (IVb). The neurotransmitters changes may explain the motor, behavioural and emotional changes that occurred with these parasites.  相似文献   

20.
Toxocariasis is a parasitic disease. Larvae of Toxocara canis, as intra-tissular parasites, can survive in human organism for 10 years. Clinical symptoms depend on massiveness of infection, organ localisation and defensive reactions of patients. 74 children were observed (in age from 1 year 8 months to 15 years). 70% of them had intraocular lesions which is the most serious complication of toxocariasis. Larva of T. canis is neurotropic. EEG revealed abnormalities in 73% of patients. The diagnosis of toxocariasis was confirmed by immunoenzymatic reaction ELISA with T. canis antigen. The patients were treated with hetrazan, if intraocular lesions were present prednisone was added. Improvement was achieved in 78% of children with intraocular lesions, in the rest effectiveness of the treatment is questionable.  相似文献   

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