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1.
A 3.5-year-old, castrated male, giant schnauzer was presented with alopecic pustular dermatitis. Immune-mediated hemolytic anemia had been diagnosed 45 days previously. At the time of presentation, the dog was receiving prednisone, azathioprine, and cyclosporine. Cutaneous protozoosis was diagnosed, and postmortem examination revealed protozoa within cutaneous, cardiac, pancreatic, and pulmonary tissues. The protozoa divided by endodyogeny, had the morphology of Toxoplasma gondii (T. gondii) tachyzoites, and stained positively with T. gondii polyclonal antibodies but not with antibodies to Neospora caninum or Sarcocystis neurona. Immunosuppression may have predisposed this dog to disseminated toxoplasmosis.  相似文献   

2.
A 10-week-old Boxer dog from Uppsala, Sweden, was killed because of hind limb paralysis. The hind limb muscles were grossly atrophied and encephalomyelitis and myositis were the predominant microscopic lesions. Neospora caninum-like tachyzoites were found in the brain and skeletal muscles, and tissue cysts were found in the brain. The organism was not Toxoplasma gondii, as T. gondii antibody was not found in the indirect fluorescent antibody test in serum samples from the puppy and the dam, and the organism in the dog's brain did not react with T. gondii antibody in the immunoperoxidase test.  相似文献   

3.
Four Korean squirrels (Tanias siberius) imported in Spain from People's Republic of China died 2 days after their arrival at a pet shop. They had neurological signs associated with generalized toxoplasmosis involving brain, lungs, liver, and the heart. Toxoplasma gondii-like tachyzoites and tissue cysts were found in organs of all four squirrels. The protozoa stained positively with T. gondii polyclonal antibodies and were ultrastructurally similar to T. gondii. Calodium (Capillaria) hepaticum infection was found in the liver of one squirrel.  相似文献   

4.
Two of 8 littermate Rottweiler dogs developed persistent diarrhea at 6.5 weeks of age. Dog 1 was euthanatized at 14 weeks of age and had hepatitis characterized by necrosis and mixed leukocyte infiltrations in association with a previously unrecognized Sarcocystis-like protozoon. The organism was free in the hepatocyte cytoplasm without a parasitophorous vacuole, had divided by schizogony, and stained with anti-Sarcocystis serum, but did not stain with anti-Toxoplasma gondii or anti-Neospora caninum serum in an immunohistochemical test. Dog 2 was euthanatized at 10 weeks of age. This dog had large necrotic, hemorrhagic mesenteric lymph nodes. Numerous T gondii tachyzoites were observed in association with these lesions. The organism divided by endodyogeny and stained specifically with anti-T gondii serum.  相似文献   

5.
Toxoplasma gondii infection was diagnosed in a full term stillborn reindeer (Rangifer tarandus) fetus. The fetus had encephalitis and placentitis associated with T. gondii. Tissue cysts were identified histologically in sections of brain and tachyzoites were present in placenta and the myocardium. Protozoa in the brain, heart, and placenta stained positively with T. gondii antibodies, but not with Neospora caninum antibodies in an immunohistochemical test. The dam of the fetus had a 1:12,800 titer to T. gondii in the modified agglutination test employing whole tachyzoites and mercaptoethanol. This is the first confirmed report of T. gondii infection in reindeer.  相似文献   

6.
Newly recognized fatal protozoan disease of dogs   总被引：46，自引：0，他引：46  
Histologic sections and case histories from 23 dogs with proven fatal toxoplasmosis-like illness at the Angell Memorial Animal Hospital were reviewed. Toxoplasma gondii was identified in 13 dogs. A newly identified parasite, Neospora caninum, structurally distinct from T gondii, was found in 10 dogs. The newly discovered organism, belonging to a new genus and new species, formed meronts in many tissues of the dogs, especially the brain and spinal cord. Neospora caninum was located directly in the host cell cytoplasm without a parasitophorous vacuole; it divided by endodyogeny, contained more than 11 rhoptries, and did not react with the anti-T gondii serum in the immunoperoxidase test. Meningoencephalomyelitis and myositis were the main lesions associated with N caninum. Ulcerative and fistulous dermatitis was the major lesion in 1 dog.  相似文献   

7.
CpG-oligodeoxynucleotides enhance porcine immunity to Toxoplasma gondii   总被引：2，自引：0，他引：2  
Protection against a challenge infection with Toxoplasma gondii VEG strain oocysts was examined in pigs after vaccination with T. gondii RH strain tachyzoites with or without a porcine specific synthetic oligodeoxynucleotides (ODN) containing immunostimulatory CpG motifs. Six groups of pigs were immunized with incomplete Freund's adjuvant (IFA) and either vehicle, tachyzoites alone or in combination with three different doses of CpG ODN or with CpG ODN alone. Protection from challenge was significantly (P < 0.05) improved in pigs vaccinated using CpG ODN as an adjuvant with tachyzoites compared to all other groups. The CpG ODN tachyzoite-immunized pigs also had higher serum parasite specific IgG antibody, no clinical signs of disease, and 52% had no demonstrable tissue cysts after the challenge infection. These data indicate that CpG ODN is a potential safe and effective adjuvant for the T. gondii RH strain vaccine in pigs.  相似文献   

8.
Tachyzoites, bradyzoites (in tissue cysts), and sporozoites (in oocysts) are the three infectious stages of Toxoplasma gondii. The prepatent period (time to shedding of oocysts after primary infection) varies with the stage of T. gondii ingested by the cat. The prepatent period (pp) after ingesting bradyzoites is short (3-10 days) while it is long (18 days or longer) after ingesting oocysts or tachyzoites, irrespective of the dose. The conversion of bradyzoites to tachyzoites and tachyzoites to bradyzoites is biologically important in the life cycle of T. gondii. In the present paper, the pp was used to study in vivo conversion of tachyzoites to bradyzoites using two isolates, VEG and TgCkAr23. T. gondii organisms were obtained from the peritoneal exudates (pex) of mice inoculated intraperitoneally (i.p.) with these isolates and administered to cats orally by pouring in the mouth or by a stomach tube. In total, 94 of 151 cats shed oocysts after ingesting pex. The pp after ingesting pex was short (5-10 days) in 50 cats, intermediate (11-17) in 30 cats, and long (18 or higher) in 14 cats. The strain of T. gondii (VEG, TgCKAr23) or the stage (bradyzoite, tachyzoite, and sporozoite) used to initiate infection in mice did not affect the results. In addition, six of eight cats fed mice infected 1-4 days earlier shed oocysts with a short pp; the mice had been inoculated i.p. with bradyzoites of the VEG strain and their whole carcasses were fed to cats 1, 2, 3, or 4 days post-infection. Results indicate that bradyzoites may be formed in the peritoneal cavities of mice inoculated intraperitoneally with T. gondii and some bradyzoites might give rise directly to bradyzoites without converting to tachyzoites.  相似文献   

9.
为了研究和探索磺胺氯吡嗪抗弓形虫的作用机理,构建磺胺氯吡嗪处理弓形虫的抑制性消减文库.将刚地弓形虫(Toxoplasma gondii)RH株速殖子腹腔注射(10000个/只鼠)感染昆明系小鼠,大量收集并纯化速殖子.用250 mg/mL磺胺氯吡嗪PBS溶液和PBS分别浸泡速殖子,37℃恒温箱孵育2h,分别提取虫体的总RNA和mRNA,以PBS处理的正常虫体cDNA为驱动组,以药物处理虫体cDNA为实验组,构建药物处理前后弓形虫速殖子的抑制性消减文库,对部分阳性克隆进行测序和序列分析.结果显示,提取的虫体总RNA纯度高,合成的双链cDNA经RsaⅠ酶切反应较完全;从消减文库中随机选择100个阳性克隆进行PCR扩增,其插入片段长度在200～750 bp之间,文库的重组率达93％以上;随机挑取30个阳性克隆进行测序,获得11个单一序列,Blast分析显示有7个单一有效EST序列与已知蛋白质相似性较高.结果表明,已成功构建磺胺氯吡嗪处理弓形虫速殖子的抑制性消减cDNA文库,并对部分阳性克隆进行了初步分析,为深入研究磺胺氯吡嗪的抗弓形虫机制和寻找药物作用的关键靶分子奠定了基础.  相似文献   

10.
A 3-year-old 4-kg neutered male domestic shorthair cat died within 5 days after onset of fever and respiratory distress. At necropsy, all tissues were icteric, and the liver had a diffuse reticular pattern. Histologically, hepatitis and encephalitis were associated with Toxoplasma gondii tachyzoites. Toxoplasma gondii female gamonts and oocysts were found in epithelial cells of intact villi and in epithelial cells desquamated into the lumen. Finding of acute hepatitis and T gondii oocysts in an adult cat without detectable immunodeficiency is unusual, because adult cats rarely have clinical signs of toxoplasmosis during the oocyst-shedding phase.  相似文献   

11.
Toxoplasma gondii tachyzoites were seen in the placenta of a late-term aborted Greenland muskox (Ovibos moschatus wardi) fetus in a captive herd at the San Francisco Zoo. The organism stained with anti-T. gondii polyclonal rabbit serum but not with anti-Neospora caninum serum. The dam had a Toxoplasma titer of > or =1:3,200 at the time of abortion and in each of the previous 3 yr (modified agglutination test). The muskox is a new host record for T. gondii.  相似文献   

12.
The RH strain of Toxoplasma gondii is highly virulent; 1 infective organism is uniformly lethal for mice. Three pigs inoculated SC with 10(3) tachyzoites of the RH strain developed fever, but otherwise remained normal, and T gondii was not demonstrated in their tissues by bioassay into mice. To determine whether vaccination with the RH strain could induce protective immunity to oral challenge with T gondii oocysts, 12 pigs were divided into 3 groups (A, B, C) of 4 pigs each. Pigs in groups A and B were inoculated IM with 10(6) tachyzoites of the RH strain and 4 pigs in group C served as uninoculated controls. Except for fever, the pigs remained clinically normal after inoculation with the RH strain and T gondii was not found by bioassay in mice of tissues from 4 pigs euthanatized 64 days after inoculation. Pigs in groups B and C were challenge-inoculated orally with 10(4) (4 pigs) or 10(5) (4 pigs) T gondii oocysts 72 days after vaccination with the RH strain. The previously uninoculated pigs developed fever, anorexia, and diarrhea from 3 to 8 days after the oocyst challenge. One of the 2 pigs given 10(5) oocysts became moribund because of toxoplasmosis and was euthanatized 9 days after inoculation. Pigs vaccinated with the RH strain remained free of clinical signs after challenge with oocysts. Results of the bioassays indicated that fewer tissue cysts developed in the RH strain-vaccinated pigs than in the previously uninoculated control pigs.  相似文献   

13.
A female 1-year-old dog died suddenly and was submitted for necropsy. Numerous grey-tan-colored nodules were seen in the lungs, brain and lymph nodes. Microscopically, the predominant lesion was necrosis associated with numerous Toxoplasma gondii tachyzoites. The parasites reacted positively with anti-T. gondii serum in an immunohistochemical test. Schizonts of Hepatozoon canis were seen in sections of lymph nodes and the spleen.  相似文献   

14.
Wallabies and other Australian marsupials are among the most susceptible species to Toxoplasma gondii. Fatal generalized toxoplasmosis was diagnosed in two captive 3 year-old female Bennett's wallabies (Macropus rufogriseus) from Argentina (w 1 and w 2) with a history of sudden death. Both animals had internal joeys which died 2 days after their mothers. Serologically, both females and one adult male without clinical signs from the same enclosure (w 3) had antibody titers for T. gondii>or=800 by the modified agglutination test (MAT); another adult male (w 4) was negative (MAT titer<25). Microscopically, tachyzoites were observed associated to non-suppurative meningoencephalitis, hepatitis, myositis, myocarditis and severe enteritis in hematoxylin and eosin stained sections from both w 1 and w 2. Immunohistochemically, parasites in heart, brain and liver sections of both female wallabies reacted with T. gondii antiserum. T. gondii was isolated from brain tissues of w 1 and w 2 by bioassay in mice and by culture in bovine monocytes and both isolates were cryopreserved. Genomic DNA was isolated from tachyzoites grown in cultures derived from both animals. The primer pair B22/B23 specific for T. gondii produced 115bp amplicons on poliacrylamide electrophoretic gels. Stray cats were suspected as the possible source of infection. Not all infected macropods were ill, showing that the infection may be asymptomatic and is not always fatal. A vertical infection could not be proved in the joey from w 2. As far as we know, this is the first confirmed report of toxoplasmosis in Bennet's wallabies in Argentina.  相似文献   

15.
An 8-year-old, male domestic shorthair cat was referred to the Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania with a 3-day history of lethargy, inappetance, hyperemic skin nodules, coughing, and vomiting. Laboratory results included nonregenerative anemia, lymphopenia, thrombocytopenia, hypoalbuminemia, hyponatremia, and increased alanine aminotransferase and aspartate aminotransferase activities. Cytology of the skin nodules revealed many spindle- to crescent-shaped protozoal organisms, with morphology consistent with Toxoplasma gondii or Neospora caninum. Gross necropsy, histopathologic, immunohistochemical, and transmission electron microscopic findings confirmed a systemic protozoal infection; however, the organism exhibited characteristics of both N caninum and T gondii. Diagnosis of a T gondii-like infection was based on internal structures of the organism and positive reaction to rabbit polyclonal antibodies to T gondii. Reports of toxoplasmic dermatitis are rare in the cat and dog, and this is the first reported diagnosis of T gondii-like protozoa in skin aspirates.  相似文献   

16.
A 3-month-old male Golden Retriever puppy was evaluated for lethargy and fever of 2-days duration. Results of a CBC and biochemical profile revealed marked eosinophilia (6.3 X 10(3)/microL; reference interval 0.1-1.2 X 10(3)/microL), moderate thrombocytopenia, and increased activities of alanine aminotransferase, aspartate aminotransferase, and creatine kinase. Hepatomegaly and peritoneal effusion were found using abdominal ultrasound. Peritoneal fluid analysis revealed eosinophilic inflammation (23,000 nucleated cells/microL with 88% eosinophils). Despite supportive treatment the puppy's condition deteriorated rapidly; euthanasia was requested, and a necropsy performed. Microscopically, there was marked necrosuppurative and eosinophilic hepatitis with vasculitis. Numerous hepatocytes contained protozoal organisms suspected to be Toxoplasma gondii or Neospora caninum. However, serum was negative for both T gondii and N caninum antibodies; polymerase chain reaction assay on hepatic tissue was negative for both organisms; and immunohistochemical evaluation of hepatic tissue using serum raised against T gondii, N caninum, and Sarcocystis neurona also was negative. Schizont morphology suggested that merozoites replicated by endopolygeny, forming rosettes around a central residual body. Transmission electron microscopy revealed that merozoites lacked rhoptries. These findings were consistent with a diagnosis of Sarcocystis canis, an apicomplexan parasite with an unknown life cycle.  相似文献   

17.
Generalized neosporosis was diagnosed in a 2-month-old boxer puppy. The dog had a history of progressive paralysis and muscle atrophy, followed by cervical weakness, stiff jaws and dysphagia. The dog had a 1:12,800 antibody titer for Neospora caninum and was negative for antibodies to Toxoplasma gondii by the indirect fluorescent antibody test (IFAT). After euthanasia a complete necropsy was carried out. The puppy had a megaesophagus. Microscopically, tachyzoites and tissue cysts were observed in histologic brain sections. Severe myositis was observed in esophagus and striated muscle sections and several groups of tachyzoites were associated with these lesions. Immunohistochemically, parasites in the brain and striated muscle reacted to anti-N. caninum antiserum. Western blot analysis allowed the identification of three major and four minor antigens of N. caninum tachyzoites corresponding to 30, 37, 45-kDa and 28, 29, 43, 47 and 67-kDa bands, respectively. Cerebral homogenate of the dog was inoculated into four Mongolian gerbils (Meriones unguiculatus). Forty-nine days after inoculation, all the gerbils had positive IFAT titers to N. caninum (1:200, 1:400, 1:100 and 1:400). Genomic DNA was isolated from the brain, lung and striated muscle from the puppy and from the brain of one of the inoculated gerbils. The N. caninum specific primer pair Np 6/21 produced 328 bp amplicons on electrophoretic gels. This is the first confirmed clinical case of generalized canine neosporosis in Argentina.  相似文献   

18.
The study evaluated the efficiency of diagnostic laboratory methods to detect anti-Toxoplasma gondii antibodies in paired serum and aqueous humour samples from experimentally infected pigs. 18-mixed breed pigs were used during the experiment; these were divided into two groups, G1 (infected group, n=10) and G2 (uninfected group, n=8). Infection was performed with 4 x 10(4) VEG strain oocysts at day 0 by the oral route in G1 animals. All pigs were euthanized at day 60, when retina, aqueous humour, and blood samples were collected. Anti-T. gondii antibody levels were assessed in serum (s) and aqueous humour (ah) by indirect immunofluorescence assay (IFA), modified agglutination test (MAT), m-ELISA (using crude membranes from T. gondii tachyzoites as antigen) and r-ELISA (using rhoptries from T. gondii tachyzoites as antigen). Polymerase chain reactions (PCR) of samples from the retina were performed by using Tox4 and Tox5 primers. Antibody titers of G1 animals ranged from 128 to 1024 and from 16 to 256 in serum and aqueous humour, respectively. There were differences in the correlation coefficients between IFA(s) x IFA (ah) (r=0.62, P=0.05), MAT(s) x MAT (ah) (r=0.97, P<0.0001); however, there was no significant difference between r-ELISA(s) x r-ELISA (ah) (r= 0.14, P=0.7). Antibodies present in serum and aqueous humour recognized similar antigens. Samples of retina were positive by PCR in 30% (3/10) of infected pigs. G2 animals remained without antibody levels and were PCR negative throughout the experiment. These results suggest that the use of a combination of tests and immunoblotting for paired aqueous humour and serum samples could improve the sensitivity and specificity for the diagnosis of ocular toxoplasmosis.  相似文献   

19.
Dual Sarcocystis neurona and Toxoplasma gondii infection was observed in a Northern sea otter from Washington, USA. The animal was found stranded, convulsed, and died shortly thereafter. Encephalitis caused by both S. neurona and T. gondii was demonstrated in histological sections of brain. Immunohistochemical examination of sections with S. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. PCR of brain tissue from the sea otter using primer pairs JNB33/JNB54 resulted in amplification of a 1100 bp product. This PCR product was cut in to 884 and 216 bp products by Dra I but was not cut by Hinf I indicating that it was S. neurona [J. Parasitol. 85 (1999) 221]. No PCR product was detected in the brain of a sea otter which had no lesions of encephalitis. Examination of brain sections using T. gondii specific antisera demonstrated tachyzoites and tissue cysts of T. gondii. The lesions induced by T. gondii suggested that the sea otter was suffering from reactivated toxoplasmosis. T. gondii was isolated in mice inoculated with brain tissue. A cat that was fed infected mouse brain tissue excreted T. gondii oocysts which were infective for mice. This is apparently the first report of dual S. neurona and T. gondii in a marine mammal.  相似文献   

20.
A 9-year-old female, domestic short hair cat was presented with sudden onset of polyuria/polydipsia, and hundreds of cutaneous nodules. Prior to referral, the cat had had four skin nodules that were treated with steroids. The four skin nodules then multiplied to form more than 100 ulcerated and nonulcerated nodules located all over the trunk. Clinical evaluation revealed hypothermia and respiratory distress. Cytology from both skin nodules and bronchoalveolar lavage showed macrophages and small organisms whose shape and size were indicative of Toxoplasma spp., or similar organisms. Feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) serology results were negative. The cat was seropositive for Toxoplasma (IgG 1 : 640) and Neospora (1 : 80) infections. The cat died soon after referral. Necropsy revealed pyothorax, necrotic/purulent pneumonia, haemorrhagic spots on kidneys and mesentery. Histopathology from skin nodules showed diffuse, deep necrotic dermatitis/panniculitis, vasculitis and disseminated free and grouped protozoa. The parasites were found in lungs, spleen, kidneys and liver. Immunohistochemistry on skin tissue with anti-Toxoplasma gondii and Neospora caninum antibodies gave positive results with both. Electron microscopy showed single and grouped tachyzoites with morphological features of T. gondii, often within macrophages. Samples of cutaneous nodules and bronchoalveolar fluid were examined by a polymerase chain reaction (PCR) assay for detecting apicomplexa coccidia. PCR results were consistent only with T. gondii infection. Therefore, immunohistochemistry positivity for N. caninum was considered a cross-reaction and a diagnosis of cutaneous and visceral toxoplasmosis was made.  相似文献   

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