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1.
Faecal samples of 24,106 cats from Germany and other European countries were examined microscopically in a veterinary laboratory in Germany between October 2004 and November 2006 to estimate the prevalence of animals shedding Toxoplasma gondii or Hammondia hammondi oocysts. Oocysts of 9-15 microm size with a morphology similar to that of H. hammondi and T. gondii were found in 74 samples (0.31%). A total of 54 samples were further characterised to achieve a species diagnosis and to determine the genotype of T. gondii isolates by PCR and PCR-RFLP. From these samples, 48 isolates were obtained: 26 (0.11%) were finally identified as T. gondii and 22 (0.09%) as H. hammondi. T. gondii-positive samples came from Germany, Austria, France and Switzerland while H. hammondi was detected in samples from Germany, Austria and Italy. In two samples (one T. gondii and one H. hammondi), PCR indicated the presence of Hammondia heydorni DNA. No Neospora caninum DNA was detected in any of the feline faecal samples. Twenty-two of the 26 T. gondii isolates could be genotyped. A PCR-RFLP analysis for the SAG2, SAG3, GRA6 and BTUB genes revealed T. gondii genotype II in all cases. Morphologically, H. hammondi oocysts exhibited a statistically significantly smaller Length-Width-Ratio than T. gondii oocysts.  相似文献   

2.
The cat is the definitive host of Toxoplasma gondii and plays an important role in the transmission of this and other coccidian parasites, e.g. Hammondia hammondi, a protozoon closely related and morphologically similar to T. gondii. A number of techniques to detect T. gondii nucleic acids in feline faeces are described and several extraction kits for isolating pathogen DNA from faeces or soil are commercially available. To compare the performance of such kits with regard to isolating oocyst DNA, a feline sample that had tested negative for coccidian parasites including T. gondii and H. hammondi was spiked with 10(4), 10(3), 10(2), 50 and 10 H. hammondi oocysts. Several ready-to-use stool or soil kits and an in-house method were then used to extract parasite DNA from these spiked faecal samples. Of six kits tested, two were found suitable for the detection of H. hammondi oocysts DNA by the polymerase chain reaction (PCR) in faecal samples with a detection limit of 250 oocysts per 1 g of faecal sample. These two kits revealed a similar, even slightly lower detection limit (50 oocysts per 1 g of sample) when tested with faecal samples spiked with T gondii oocysts.  相似文献   

3.
Fifteen pregnant does were inoculated orally with 10 to 1,000 oocysts of the GT-1 strain of Toxoplasma gondii. Two does were euthanatized on postinoculation days (PID) 10 and 14, and the remaining 13 does aborted or delivered kids transplacentally infected with T gondii on PID 9 to 65. Tissues of all 34 fetuses or kids from the inoculated does were examined for gross and microscopic lesions. Placental necrosis and encephalomyelitis were the most prominent lesions. Toxoplasma gondii invaded the fetal placenta between PID 9 and 11 and invaded fetal tissues 2 to 3 days later. Necrosis attributed to toxoplasmosis, confined to cotyledons, was found in all placentas examined on PID 18. Encephalomyelitis was found in most fetuses or kids between PID 30 and 65. Lesions in fetal tissues were sparse. Because T gondii is rarely found in lesions, histologic examination of the fetal tissues is not likely to help in diagnosing every case of transplacentally induced toxoplasmosis in goats.  相似文献   

4.
Ten 75- to 105-day-pregnant does each were inoculated orally within 1 million (2 does), 10,000 (4 does), or 1,000 (4 does) sporocysts of Sarcocystis from coyote feces. Two does not inoculated with sporocysts served as controls. The 2 does inoculated with 1 million sporocysts died from acute sarcocystosis 21 and 22 days after inoculation (DAI), and each had 2 dead fetuses. The 4 does inoculated with 10,000 sporocysts were ill 19 to 33 DAI but survived; 1 aborted at 33 DAI, 1 had a live kid that died within 2 hours of birth 31 DAI, 1 aborted 2 dead fetuses 23 DAI, and 1 had a normal kid 56 DAI. The 4 does inoculated with 1,000 sporocysts and the 2 control does remained clinically normal and had normal kids. Does and their offspring were killed within 24 hours of parturition, and their tissues were examined histologically and microbiologically. Meronts of Sarcocystis were found in the maternal placenta of does inoculated with 1 million sporocysts. Sarcocystis was not found in the placenta, fetuses, or tissues of kids from does inoculated with 10,000 or 1,000 sporocysts, or from control does. Other abortifacient agents were not found in the placenta, fetuses, or kids from any does.  相似文献   

5.
Three of 8 goats on a Maryland farm aborted or had dystocia associated with toxoplasmosis during the winter of 1984. Doe 1 aborted a decomposed fetus 30 days before term. Modified agglutination test (MAT) antibody titers against Toxoplasma gondii were found in pleural fluid of the fetus (1:1,024) and in serum of doe (1:4,096 at 31 days after abortion). Doe 2 aborted a fetus 5 days before term; MAT antibody was found in the pleural fluid of the fetus (1:16,384) and in the doe's serum (1:4,096 on the day of abortion). Placenta from both does had foci of necrosis characteristic of toxoplasmosis, and T gondii was identified in lesions. Doe 3 had dystocia 7 days before term and a partially decomposed fetus was delivered by cesarian section; MAT was found in pleural fluid of the fetus (1:1,024) and in serum from the doe (1:4,096 on the day of abortion). Focal gliosis and calcification were seen in brain specimens from 2 of the 3 fetuses. None of the does produced milk after abortion. Two other does (No. 4 and 5) delivered apparently healthy kids transplacentally infected with T gondii; MAT in serum of both does was 1:4,096. Doe 4 delivered 3 kids; MAT titer in a serum from each kid 38 days after birth was 1:16,384. Doe 5 delivered 1 kid with a serum MAT titer of 1:1,024 at 38 days after birth. The 3 remaining does had MAT titers of 1:256, 1:16, and 1:16, and all delivered healthy kids. Epizootiologic evidence suggested that the does acquired T gondii infection from oocysts passed in feces of domestic cats on the farm. The MAT titers of 4 cats on the farm were 1:65,356; 1:1,024; 1:16; and 1:1,024.  相似文献   

6.
Toxoplasma gondii, Hammondia hammondi, Neospora caninum, Neospora hughesi and Hammondia heydorni are members of the Toxoplasmatinae sub-family. They are closely related coccidians with similarly sized oocysts. Molecular diagnostic techniques, especially those based on polymerase chain reaction (PCR), can be successfully applied for the differentiation of Hammondia-like oocysts. In this paper, we describe a rapid and simple method for the identification of H. heydorni oocysts among other members of the Toxoplasmatinae sub-family, using a heminested-PCR (hnPCR-AP10) based on a H. heydorni RAPD fragment available in molecular database. DNA of oocysts of H. heydorni yielded a specific fragment of 289-290 bp in the heminested-PCR assay. No product was yielded when the primers were used for the amplification of DNA extracted from T. gondii, N. caninum, N. hughesi and H. hammondi, thus allowing the differentiation of H. heydorni among other members of the Toxoplasmatinae sub-family. The hnPCR-AP10 was capable of detecting H. heydorni genetic sequences from suspensions with at least 10 oocysts. In conclusion, the hnPCR-AP10 proved to be a reliable method to be used in the identification of H. heydorni oocysts from feces of dogs.  相似文献   

7.
Eight female, 12- to 34-month-old, specific-pathogen free cats were inoculated orally with Toxoplasma gondii cysts on day 0, then with Isospora felis and Isospora rivolta oocysts on day 39, and cysts of Hammondia hammondi on day 86 after inoculation with Toxoplasma. All cats shed oocysts of all 4 of these coccidia within 11 postinoculation days. The female cats were caged with 4 male Toxoplasma-free cats, starting 66 days after inoculation with Toxoplasma, until they were 5 to 6 weeks pregnant. Kittens that were born were housed with their mothers until necropsied or weaned. One 42-day-old kitten shed T gondii oocysts in feces. It was necropsied 2 days later and asexual stages of Toxoplasma (types D and E), gametocytes, and oocysts were demonstrated in sections of superficial epithelial cells of its small intestine. Lesions or forms of Toxoplasma were not demonstrated histologically in tis extraintestinal organs. Toxoplasma was not isolated from feces or tissues of the remaining 47 kittens born to these 8 queens. Toxoplasma was not isolated from the 4 male cats that were caged with infected females for 53, 59, 217, and 217 days. The source of toxoplasma infection in the kitten remained unknown but was considered unlikely to be congenital or through fecal contamination. Oocysts of I felis, I rivolta, and H hammondi were not found in the feces of any kittens, indicating that these coccidia are unlikely to be transmitted congenitally.  相似文献   

8.
Acquisition of immunity to Hammondia hammondi, a newly recognized coccidian of cats, was studied in 18 specific-pathogen-free cats. One cat was given a single oral inoculation, 11 cats were given 2 oral inoculations, and 1 cat was given 3 oral inoculations of homogenized mouse carcasses containing H hammondi. In all cats, oocyst shedding began 6 to 9 days after the 1st inoculation. Oocyst shedding peaked at 1 to 2 days after the onset of shedding and lasted for 1 to 2 weeks. None of the cats became sick. Of the 11 cats inoculated twice (between 2-51 days after the 1st inoculation), 5 shed oocysts 7 to 14 days after the repeat inoculation; however, fewer oocysts were shed at this time. One cat that was inoculated thrice (14 and 51 days after the 1st inoculation) shed oocysts 14 to 17 days after the 3rd inoculation but not after the 2nd inoculation. Spontaneous oocyst shedding was studied in 9 of these 13 H hammondi-infected cats for 5 months. Two cats spontaneously shed oocysts: One cat (inoculated only once) spontaneously re-shed oocysts 21 to 24, 31 to 33, 49 to 50, and 118 to 120 days after inoculation; The other cat (inoculated twice-the 2nd time, 6 days after the 1st inoculation) re-shed oocysts 38 to 48, 85 to 89, and 133 to 136 days after the 1st inoculation. The course of H hammondi infection was studied in 5 cats given weekly injections of 6-methyl prednisolone acetate for at least 7 weeks, starting 18 days before inoculation in 2 cats, and starting 14, 34, and 45 day after inoculation in 3 cats. The induced hyperadrenocorticism did not affect the prepatent period or induce parasitism of extraintestinal organs. The 3 cats infected for 14, 34, and 45 days, re-shed oocysts after hyperadrenocorticism was induced. It was concluded that immunity to H hammondi infection in cats is less stable than immunity to the related coccidian, Toxoplasma gondii.  相似文献   

9.
Eight pregnant goats were inoculated orally with 10 to 1,000 oocysts of Toxoplasma gondii at 83 to 102 days of gestation. Serum samples from the goats and from the kids born to them were analyzed, using the Sabin-Feldman dye test (DT), a commercially available modified agglutination test (MAT), and a latex agglutination test. Six of the does were observed for greater than 1 year; during this time, they delivered twice. All does developed DT and MAT antibody titers of greater than or equal to 1:2,048 within 29 days after inoculation, and the high titers persisted through the 2nd pregnancy; therefore, serologic results alone should not be relied on for the diagnosis of T gondii-induced abortion in does. On the other hand, all transplacentally infected kids had DT or MAT antibody titers of 1:2,048 before ingesting colostrum, indicating the usefulness of serologic evaluation of the fetus or stillborn kid in the diagnosis of abortion. Antibody was not found in the sera of noninfected kids born to Toxoplasma-infected does. The passively acquired colostral antibody declined by 5 months. Therefore, specific antibody found in adult goats is probably actively acquired. The commercially available MAT was simple, sensitive, and reliable for the diagnosis of caprine toxoplasmosis. The latex agglutination test needs further improvement, as titers rarely exceeded 1:256.  相似文献   

10.
Congenital toxoplasmosis was diagnosed in a flock of Hampshire sheep in South Dakota. The 80 ewes produced 144 lambs, 30 of which were born dead; toxoplasmosis was diagnosed in 11 of the dead lambs. The remaining 114 lambs grew normally, but 68 (40.3%) had agglutinating Toxoplasma gondii antibodies. Modified agglutination test T gondii antibody titers for 114 lambs were: less than 100 (n = 46), 64 (n = 2), 256 (n = 1), 1,024 (n = 12), and greater than or equal to 4,096 (n = 53). Tissues of 8 seropositive lambs were bioassayed for T gondii tissue cysts. Toxoplasma gondii was isolated from the tongue and lamb chops of 7, heart of 3, and legs of lamb of all 8 lambs.  相似文献   

11.
Neospora-like protozoal infections associated with bovine abortions   总被引：9，自引：0，他引：9  
Eighty bovine fetuses with presumed protozoal infections from a previous 2-year retrospective study were examined by immunohistochemistry using antisera against Neospora caninum. In 66 (83%) of the fetuses, protozoa were found that reacted positively with anti-N. caninum sera. In three (4%) additional fetuses, protozoa identified as Sarcocystis species did not react, and in two fetuses (3%) single protozoal clusters were found only in hematoxylin and eosin-stained slides. A group of 20 fetuses were chosen for further evaluation. They included 14 fetuses from the first group of 80 fetuses plus six additional fetuses that had large numbers of protozoa in the fetal brain. The 20 fetuses were examined immunohistochemically with antisera to N. caninum, Hammondia hammondi, and Toxoplasma gondii. Protozoa from 3/20 fetuses, identified as Sarcocystis species, failed to react with any antisera. In 16/20 fetuses protozoa reacted positively to antisera against N. caninum, and in most cases reacted to H. hammondi, and weakly to one or more of the antisera against T. gondii. Thick-walled protozoal tissue cysts were found in the brain of four of these 16 fetuses by transmission electron microscopy. The cyst wall morphology was comparable to N. caninum. The results suggested that a single protozoal parasite of unknown identity was responsible for most of the bovine abortions. By immunohistochemistry, the unknown protozoon reacted most strongly and consistently to N. caninum antisera, but was antigenically distinct from N. caninum. Ultrastructurally, tissue cysts found in four fetuses most closely resembled Neospora caninum.  相似文献   

12.
Immunohistochemical diagnosis of Neospora caninum in tissue sections   总被引：10，自引：0，他引：10  
An avidin-biotin-peroxidase complex immunoperoxidase staining method was developed to detect Neospora caninum in formalin-fixed, paraffin-embedded tissue sections. Specific antiserum to N caninum was made in rabbits and used to probe tissues from dogs naturally and experimentally infected with N caninum. The test detected tachyzoites and bradyzoites of N caninum. A reaction was not observed to Toxoplasma gondii, Hammondia hammondi, Sarcocystis cruzi, S capricanis, S tenella, Besnoitia jellisoni, Caryospora bigenetica, Hepatazoon canis, Atoxoplasma sp, or the organism causing canine dermal coccidiosis. When antiserum made in rabbits to T gondii was used in the test, reaction to N caninum was not observed.  相似文献   

13.
Tissues of 20 2-3-month-old kids and 17 2-4-year old does fed Toxoplasma gondii oocysts were examined histologically. Kids were necropsied between 3 and 50 days post-inoculation (DPI) and does were necropsied between 10 and 422 DPI. Lesions were seen in tissues of all young goats fed 1000-100,000 oocysts and consisted of acute enteritis, necrosis of mesenteric lymph nodes and encephalomyelitis. Lesions were not seen in does fed 10-10,000 oocysts.  相似文献   

14.
Hospitalized animals and stray dogs were serologically tested for antibodies against Toxoplasma gondii. In addition, the data were examined for the possibility of toxoplasmosis infection being associated with the clinical diagnosis and with the discharge status (alive vs. dead). Among 1056 hospitalized animals, 17 (20%) of 86 cats, 112 (14%) of 804 dogs, 34 (26%) of 133 horses and 6 (18%) of 33 cattle had serological evidence of infection with T. gondii. Only 22 (6%) of 342 young (median age = one year) stray dogs were seropositive. The difference in antibody prevalence between hospitalized and stray dogs was thought to be due to age and dietary factors. Of 249 dogs grouped by clinical diagnosis, there was significantly (p less than 0.01) higher prevalence of seropositives among dogs with diseases of the kidney or with adrenocortical hyperfunction than among dogs hospitalized for other diseases. Of 19 dogs with diseases of the kidney and 12 with adrenocortical hyperfunction 37% and 42%, respectively, were seropositive.. There was higher risk of being discharged from the hospital dead among seropositive dogs, cattle and horses than among seronegative animals of the same species. The exception was cats, where of 69 seronegative cats 29% were dead at discharge and where of 17 seropositive cats 18% were dead at discharge. The possible effects of stress due to hospitalization need further research.  相似文献   

15.
To investigate the potential role of endogenous transplacental transmission of Toxoplasma gondii, 31 seropositive ewes presumed to be persistently infected with the parasite and 15 seronegative ewes were mated and monitored throughout pregnancy and lambing. Antibody titres were determined in precolostral sera from the liveborn lambs and in thoracic fluid from the dead lambs. A PCR for the B1 gene of T gondii was applied to the placentas from all the ewes and to the brains of the stillborn lambs. Samples of brain, lung, liver, spleen and heart from the dead lambs were examined by histopathology. No evidence of toxoplasmosis was detected by histopathology or PCR in any of the samples, but low titres of antibody to T gondii were detected in two liveborn, healthy offspring of a seropositive ewe by the immunofluorescent antibody test (3.2 per cent of pregnancies and 4.1 per cent of lambs in the seropositive group). Antibody to specific antigens of T gondii was demonstrated in sera from these two lambs by Western blotting.  相似文献   

16.
Two-tooth ewes (n=48) were immunized pre-tupping with a live Toxoplasma gondii vaccine. At midpregnancy these ewes were challenged intravenously with 1 x 105 live T. gondii tachyzoites. The strain of T. gondii used for vaccination was an incomplete strain that did not produce oocysts. It was derived by continuous twice weekly passage in mice. The lambing percentage for ewes immunized with the live vaccine was significantly higher (P<0.001 normal score) than non-vaccinated control ewes. However, vaccination did not prevent foetal or placental infection. The serological response to vaccination and challenge was measured by both the Dye test and the Indirect Haemagglutination test. No significant relationship between titre of antibody and protection in the vaccinated ewes was observed.  相似文献   

17.
The prevalence of Toxoplasma gondii in free range chickens is a good indicator of the prevalence of T. gondii oocysts in the environment because chickens feed from the ground. In the present study, prevalence of T. gondii in 121 free range chickens (Gallus domesticus) and 19 ducks (Anas sp.) from a rural area surrounding Giza, Egypt was assessed. Blood, heart, and brain from each animal were examined for T. gondii infection. Antibodies to T. gondii, assayed with the modified agglutination test (MAT), were found in 49 (40.4%) chickens in titers of 1:5 in 11, 1:10 in four, 1:20 in four, 1:40 in eight, 1:80 in 10, and 1:160 or more in 12 chickens. Antibodies were found in three ducks each with a titer of 1:80. Hearts and brains of seropositive (MAT > or = 1:5) chickens and ducks were bioassayed in mice. Additionally, hearts and brains of seronegative (MAT<1:5) animals were bioassayed in T. gondii-free cats. T. gondii was isolated from 19 of 49 seropositive chickens (one with a titer of 1:5, two with a titer of 1:20, one with a titer of 1:40, five with a titer of 1:80, three with a titer of 1:160, and seven with a titer of > or = 1:360). One cat fed tissues pooled from 15 seronegative chickens shed T. gondii oocysts, while two cats fed tissues of 34 seronegative chickens did not shed oocysts. T. gondii was isolated from one of the seropositive ducks by bioassay in mice. The two cats fed tissues from 16 seronegative ducks did not shed oocysts. Genotyping of 20 chicken isolates of T. gondii using the SAG 2 locus indicated that 17 isolates were type III and three were type II. The duck isolate of T. gondii was type III. The mice inoculated with tissue stages of all 21 isolates of T. gondii from chickens and ducks remained asymptomatic, indicating that phenotypically they were not type I because type I strains are lethal for mice. Infections with mixed genotypes were not found.  相似文献   

18.
The aim of this study was to compare the ability of a live incomplete strain (Strain 48) and a live complete strain (Strain 89) of Toxoplasma gondii to protect against abortion and congenital infection following an oral challenge of T. gondii oocysts. Sixty-nine two-tooth ewes were immunised pre-tupping with live Strain 48 of T. gondii tachyzoites and seventy ewes were immunised with Strain 89. Eighty-two serologically negative ewes served as controls. At mid-pregnancy half of the ewes were challenged orally with T. gondii oocysts (2x10(5)/ewe). The ewes vaccinated with Strain 48 were significantly (p<0.05) protected against the effects of experimental challenge and the rate of congenital infection was also significantly (p<0.15) reduced. The ewes vaccinated with Strain 89 were also significantly (p<0.05) protected. The serological response to challenge as measured by both the Dye test and the Indirect Haemagglutination test varied considerably between the two vaccinated groups.  相似文献   

19.
Lesions typical of congenital toxoplasmosis were found in 5 aborted and stillborn kids. Serological findings in 2 of these kids and all their dams supported the diagnosis of congenital toxoplasmosis. In additon. Toxoplasma gondii was isolated from twin kids.  相似文献   

20.
Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and S. canis are related protozoans that can cause mortality in many species of domestic and wild animals. Recently, T. gondii and S. neurona were recognized to cause encephalitis in marine mammals. As yet, there is no report of natural exposure of N. caninum in marine mammals. In the present study, antibodies to T. gondii and N. caninum were assayed in sera of several species of marine mammals. For T. gondii, sera were diluted 1:25, 1:50, and 1:500 and assayed in the T. gondii modified agglutination test (MAT). Antibodies (MAT > or =1:25) to T. gondii were found in 89 of 115 (77%) dead, and 18 of 30 (60%) apparently healthy sea otters (Enhydra lutris), 51 of 311 (16%) Pacific harbor seals (Phoca vitulina), 19 of 45 (42%) sea lions (Eumetopias jubatus) [corrected] 5 of 32 (16%) ringed seals (Phoca hispida), 4 of 8 (50%) bearded seals (Erignathus barbatus), 1 of 9 (11.1%) spotted seals (Phoca largha), 138 of 141 (98%) Atlantic bottlenose dolphins (Tursiops truncatus), and 3 of 53 (6%) walruses (Odobenus rosmarus). For N. caninum, sera were diluted 1:40, 1:80, 1:160, and 1:320 and examined with the Neospora agglutination test (NAT) using mouse-derived tachyzoites. NAT antibodies were found in 3 of 53 (6%) walruses, 28 of 145 (19%) sea otters, 11 of 311 (3.5%) harbor seals, 1 of 27 (3.7%) sea lions, 4 of 32 (12.5%) ringed seals, 1 of 8 (12.5%) bearded seals, and 43 of 47 (91%) bottlenose dolphins. To our knowledge, this is the first report of N. caninum antibodies in any marine mammal, and the first report of T. gondii antibodies in walruses and in ringed, bearded, spotted, and ribbon seals. Current information on T. gondii-like and Sarcocystis-like infections in marine mammals is reviewed. New cases of clinical S. canis and T. gondii infections are also reported in sea lions, and T. gondii infection in an Antillean manatee (Trichechus manatus manatus).  相似文献   

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