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J.d. Dunsmore - One of the best experts on this subject based on the ideXlab platform.
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Excystation rates and infectivity of sporocysts of Sarcocystis Cruzi exposed to different treatments and storages
Veterinary parasitology, 1997Co-Authors: Giovanni Savini, Ian D. Robertson, J.d. DunsmoreAbstract:The effect of some chemical and anatomical factors on the excystability and infectivity in cell culture of sporocysts of Sarcocystis Cruzi was investigated. A significantly (P < 0.001) higher excystation rate (ER) occurred when sodium bicarbonate was added to the excysting fluid at concentrations between 0.075 and 0.3 M. Sporocysts collected from different dogs had different ER. In contrast, although not uniformly distributed along the intestinal lumen, the sporocysts collected from the different tracts of the intestine showed similar ER. The period of storage did not affect the excystability of the sporocysts; however, it influenced the pattern of growth of the sporozoites in cell culture. Sporozoites excysted from sporocysts stored for approximately 2 years grew slower and produced significantly fewer merozoites compared to those excysted from sporocysts stored for 5-7 months.
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Class-specific antibody responses in cattle following experimental challenge with sporocysts or merozoites of Sarcocystis Cruzi.
Veterinary parasitology, 1997Co-Authors: Giovanni Savini, Ian D. Robertson, J.d. DunsmoreAbstract:An ELISA using antigen produced from merozoites of Sarcocystis Cruzi was developed to monitor specific IgM and IgG antibody, following challenge of cattle with either merozoites or sporocysts of S. Cruzi. This assay was compared with an ELISA using antigen produced from the cystozoite stage of the parasite. Both ELISAs were able to detect significant increases in levels of circulating IgM and IgG antibodies against Sarcocystis in all challenged cows; however, the magnitude of the titres was greater in the ELISA which used the antigen derived from the merozoites. This immunoassay also detected increases in the levels of IgG earlier than did the assay using antigen derived from cystozoites of S. Cruzi. Since this rise coincided with the presence of clinical signs, and was persistent for several weeks, the IgG-ELISA using antigen derived from merozoites appears to be suitable for the diagnosis of acute sarcocystiosis in cattle. Furthermore, since significant increases in the levels of circulating IgM and IgG antibodies against Sarcocystis were detected in the cows infected with merozoites of S. Cruzi, it is evident that merozoites of S. Cruzi cultured in vitro maintain their capability to replicate in the natural intermediate host.
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Studies on pathogenesis, tissue infection and congenital transmission in cows experimentally infected with Sarcocystis Cruzi by various routes.
Veterinary parasitology, 1996Co-Authors: Giovanni Savini, J.d. Dunsmore, Ian D. RobertsonAbstract:A group of nine cows, naturally infected with Sarcocystis, were challenged with Sarcocystis Cruzi: three intrarumenally with sporocysts, two intrarumenally with water (controls), two intravenously with merozoites grown in vitro and two intravenously with saline solution (controls). The animals intrarumenally challenged with sporocysts developed acute sarcocystiosis and produced stillborn calves, whereas those intravenously challenged with merozoites suffered from subclinical sarcocystiosis with premature births. No parasites were found in calves from cows challenged with sporocysts; however, a meront of Sarcocystis was found in calves from cows the cerebrospinal fluid of a calf from a cow intravenously inoculated with merozoites of S. Cruzi. This is the first time that merozoites of S. Cruzi grown in vitro have been demonstrated to retain the ability to infect their natural intermediate host and complete their life cycle.
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Evaluation of a serological test system for the diagnosis of Sarcocystis Cruzi infection in cattle using S. Cruzi merozoite antigen
Veterinary parasitology, 1994Co-Authors: Giovanni Savini, J.d. Dunsmore, Ian D. RobertsonAbstract:Fifty serum samples were examined by enzyme-linked immunosorbent assay (ELISA) for antibodies directed against crude antigens isolated from cystozoites and merozoites of Sarcocystis Cruzi and Sarcocystis tenella/Sarcocystis arieticanis and merozoites of Toxoplasma gondii. Of these 50 samples, 25 were from cattle originating from an area where the prevalence of S. Cruzi was found to be very low (9%) and in which no cystozoites were detected, and 25 were from cattle which were found by a digestion method to be heavily infected with S. Cruzi. A very high correlation was observed between the parasitological data and the results obtained from the serological assays which used antigens from either cystozoites or merozoites of S. Cruzi. The assay using the antigen derived from merozoites provided the best result for discriminating infected and non-infected animals. There was some cross-reactivity between the antigen derived from cystozoites of heterologous species of Sarcocystis and S. Cruzi antibodies, and some cross-reactivity between antigen of T. gondii and antibodies to S. Cruzi. The reproducibility of the assays was found to be high and similar results were observed when the sera were tested on two separate occasions. The unpurified S. Cruzi merozoite antigen produced in vitro is relatively accurate in discriminating positive and negative animals and may be used for diagnosis in economically important hosts such as cattle and sheep.
Ian D. Robertson - One of the best experts on this subject based on the ideXlab platform.
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Excystation rates and infectivity of sporocysts of Sarcocystis Cruzi exposed to different treatments and storages
Veterinary parasitology, 1997Co-Authors: Giovanni Savini, Ian D. Robertson, J.d. DunsmoreAbstract:The effect of some chemical and anatomical factors on the excystability and infectivity in cell culture of sporocysts of Sarcocystis Cruzi was investigated. A significantly (P < 0.001) higher excystation rate (ER) occurred when sodium bicarbonate was added to the excysting fluid at concentrations between 0.075 and 0.3 M. Sporocysts collected from different dogs had different ER. In contrast, although not uniformly distributed along the intestinal lumen, the sporocysts collected from the different tracts of the intestine showed similar ER. The period of storage did not affect the excystability of the sporocysts; however, it influenced the pattern of growth of the sporozoites in cell culture. Sporozoites excysted from sporocysts stored for approximately 2 years grew slower and produced significantly fewer merozoites compared to those excysted from sporocysts stored for 5-7 months.
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Class-specific antibody responses in cattle following experimental challenge with sporocysts or merozoites of Sarcocystis Cruzi.
Veterinary parasitology, 1997Co-Authors: Giovanni Savini, Ian D. Robertson, J.d. DunsmoreAbstract:An ELISA using antigen produced from merozoites of Sarcocystis Cruzi was developed to monitor specific IgM and IgG antibody, following challenge of cattle with either merozoites or sporocysts of S. Cruzi. This assay was compared with an ELISA using antigen produced from the cystozoite stage of the parasite. Both ELISAs were able to detect significant increases in levels of circulating IgM and IgG antibodies against Sarcocystis in all challenged cows; however, the magnitude of the titres was greater in the ELISA which used the antigen derived from the merozoites. This immunoassay also detected increases in the levels of IgG earlier than did the assay using antigen derived from cystozoites of S. Cruzi. Since this rise coincided with the presence of clinical signs, and was persistent for several weeks, the IgG-ELISA using antigen derived from merozoites appears to be suitable for the diagnosis of acute sarcocystiosis in cattle. Furthermore, since significant increases in the levels of circulating IgM and IgG antibodies against Sarcocystis were detected in the cows infected with merozoites of S. Cruzi, it is evident that merozoites of S. Cruzi cultured in vitro maintain their capability to replicate in the natural intermediate host.
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Studies on pathogenesis, tissue infection and congenital transmission in cows experimentally infected with Sarcocystis Cruzi by various routes.
Veterinary parasitology, 1996Co-Authors: Giovanni Savini, J.d. Dunsmore, Ian D. RobertsonAbstract:A group of nine cows, naturally infected with Sarcocystis, were challenged with Sarcocystis Cruzi: three intrarumenally with sporocysts, two intrarumenally with water (controls), two intravenously with merozoites grown in vitro and two intravenously with saline solution (controls). The animals intrarumenally challenged with sporocysts developed acute sarcocystiosis and produced stillborn calves, whereas those intravenously challenged with merozoites suffered from subclinical sarcocystiosis with premature births. No parasites were found in calves from cows challenged with sporocysts; however, a meront of Sarcocystis was found in calves from cows the cerebrospinal fluid of a calf from a cow intravenously inoculated with merozoites of S. Cruzi. This is the first time that merozoites of S. Cruzi grown in vitro have been demonstrated to retain the ability to infect their natural intermediate host and complete their life cycle.
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Evaluation of a serological test system for the diagnosis of Sarcocystis Cruzi infection in cattle using S. Cruzi merozoite antigen
Veterinary parasitology, 1994Co-Authors: Giovanni Savini, J.d. Dunsmore, Ian D. RobertsonAbstract:Fifty serum samples were examined by enzyme-linked immunosorbent assay (ELISA) for antibodies directed against crude antigens isolated from cystozoites and merozoites of Sarcocystis Cruzi and Sarcocystis tenella/Sarcocystis arieticanis and merozoites of Toxoplasma gondii. Of these 50 samples, 25 were from cattle originating from an area where the prevalence of S. Cruzi was found to be very low (9%) and in which no cystozoites were detected, and 25 were from cattle which were found by a digestion method to be heavily infected with S. Cruzi. A very high correlation was observed between the parasitological data and the results obtained from the serological assays which used antigens from either cystozoites or merozoites of S. Cruzi. The assay using the antigen derived from merozoites provided the best result for discriminating infected and non-infected animals. There was some cross-reactivity between the antigen derived from cystozoites of heterologous species of Sarcocystis and S. Cruzi antibodies, and some cross-reactivity between antigen of T. gondii and antibodies to S. Cruzi. The reproducibility of the assays was found to be high and similar results were observed when the sera were tested on two separate occasions. The unpurified S. Cruzi merozoite antigen produced in vitro is relatively accurate in discriminating positive and negative animals and may be used for diagnosis in economically important hosts such as cattle and sheep.
Giovanni Savini - One of the best experts on this subject based on the ideXlab platform.
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Excystation rates and infectivity of sporocysts of Sarcocystis Cruzi exposed to different treatments and storages
Veterinary parasitology, 1997Co-Authors: Giovanni Savini, Ian D. Robertson, J.d. DunsmoreAbstract:The effect of some chemical and anatomical factors on the excystability and infectivity in cell culture of sporocysts of Sarcocystis Cruzi was investigated. A significantly (P < 0.001) higher excystation rate (ER) occurred when sodium bicarbonate was added to the excysting fluid at concentrations between 0.075 and 0.3 M. Sporocysts collected from different dogs had different ER. In contrast, although not uniformly distributed along the intestinal lumen, the sporocysts collected from the different tracts of the intestine showed similar ER. The period of storage did not affect the excystability of the sporocysts; however, it influenced the pattern of growth of the sporozoites in cell culture. Sporozoites excysted from sporocysts stored for approximately 2 years grew slower and produced significantly fewer merozoites compared to those excysted from sporocysts stored for 5-7 months.
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Class-specific antibody responses in cattle following experimental challenge with sporocysts or merozoites of Sarcocystis Cruzi.
Veterinary parasitology, 1997Co-Authors: Giovanni Savini, Ian D. Robertson, J.d. DunsmoreAbstract:An ELISA using antigen produced from merozoites of Sarcocystis Cruzi was developed to monitor specific IgM and IgG antibody, following challenge of cattle with either merozoites or sporocysts of S. Cruzi. This assay was compared with an ELISA using antigen produced from the cystozoite stage of the parasite. Both ELISAs were able to detect significant increases in levels of circulating IgM and IgG antibodies against Sarcocystis in all challenged cows; however, the magnitude of the titres was greater in the ELISA which used the antigen derived from the merozoites. This immunoassay also detected increases in the levels of IgG earlier than did the assay using antigen derived from cystozoites of S. Cruzi. Since this rise coincided with the presence of clinical signs, and was persistent for several weeks, the IgG-ELISA using antigen derived from merozoites appears to be suitable for the diagnosis of acute sarcocystiosis in cattle. Furthermore, since significant increases in the levels of circulating IgM and IgG antibodies against Sarcocystis were detected in the cows infected with merozoites of S. Cruzi, it is evident that merozoites of S. Cruzi cultured in vitro maintain their capability to replicate in the natural intermediate host.
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Studies on pathogenesis, tissue infection and congenital transmission in cows experimentally infected with Sarcocystis Cruzi by various routes.
Veterinary parasitology, 1996Co-Authors: Giovanni Savini, J.d. Dunsmore, Ian D. RobertsonAbstract:A group of nine cows, naturally infected with Sarcocystis, were challenged with Sarcocystis Cruzi: three intrarumenally with sporocysts, two intrarumenally with water (controls), two intravenously with merozoites grown in vitro and two intravenously with saline solution (controls). The animals intrarumenally challenged with sporocysts developed acute sarcocystiosis and produced stillborn calves, whereas those intravenously challenged with merozoites suffered from subclinical sarcocystiosis with premature births. No parasites were found in calves from cows challenged with sporocysts; however, a meront of Sarcocystis was found in calves from cows the cerebrospinal fluid of a calf from a cow intravenously inoculated with merozoites of S. Cruzi. This is the first time that merozoites of S. Cruzi grown in vitro have been demonstrated to retain the ability to infect their natural intermediate host and complete their life cycle.
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Evaluation of a serological test system for the diagnosis of Sarcocystis Cruzi infection in cattle using S. Cruzi merozoite antigen
Veterinary parasitology, 1994Co-Authors: Giovanni Savini, J.d. Dunsmore, Ian D. RobertsonAbstract:Fifty serum samples were examined by enzyme-linked immunosorbent assay (ELISA) for antibodies directed against crude antigens isolated from cystozoites and merozoites of Sarcocystis Cruzi and Sarcocystis tenella/Sarcocystis arieticanis and merozoites of Toxoplasma gondii. Of these 50 samples, 25 were from cattle originating from an area where the prevalence of S. Cruzi was found to be very low (9%) and in which no cystozoites were detected, and 25 were from cattle which were found by a digestion method to be heavily infected with S. Cruzi. A very high correlation was observed between the parasitological data and the results obtained from the serological assays which used antigens from either cystozoites or merozoites of S. Cruzi. The assay using the antigen derived from merozoites provided the best result for discriminating infected and non-infected animals. There was some cross-reactivity between the antigen derived from cystozoites of heterologous species of Sarcocystis and S. Cruzi antibodies, and some cross-reactivity between antigen of T. gondii and antibodies to S. Cruzi. The reproducibility of the assays was found to be high and similar results were observed when the sera were tested on two separate occasions. The unpurified S. Cruzi merozoite antigen produced in vitro is relatively accurate in discriminating positive and negative animals and may be used for diagnosis in economically important hosts such as cattle and sheep.
L. Venturini - One of the best experts on this subject based on the ideXlab platform.
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frequency of horizontal and vertical transmission for Sarcocystis Cruzi and neospora caninum in dairy cattle
Veterinary Parasitology, 2009Co-Authors: Gaston More, W. Basso, D. Bacigalupe, M. C. Venturini, Magdalena Rambeaud, F Beltrame, B Ramirez, L. VenturiniAbstract:Sarcocystis Cruzi and Neospora caninum infections in cattle are common throughout the world, and cause important economical losses. N. caninum can be transmitted horizontally by ingestion of oocysts or vertically from the infected dam to the fetus via the placenta. Vertical transmission for S. Cruzi is infrequent and horizontal transmission is considered the most important route of infection. The objectives of this study were to evaluate the frequency of horizontal and vertical transmission for S. Cruzi and N. caninum in a dairy cattle herd and to analyze IFAT titers as predictors of vertical transmission. Serum samples (n = 173) were collected from dairy calves at birth prior to colostrum ingestion and from their dams. In addition, 12 calves were also sampled after ingestion of colostrum, 25 female calves were sampled at 7 months, and 81 of the dams were also sampled at breeding. Sera were evaluated for S. Cruzi and N. caninum antibodies by IFAT starting at 1:25 dilution. For S. Cruzi, vertical transmission frequency was 1.7%, and all female calves evaluated at 7 months and cows were seropositive. Seroprevalence for N. caninum was 80.9% in cows and 30% in precolostrum calves. Vertical transmission frequency was 37.1%. Cows with high antibody titers (> or = 400) showed higher vertical transmission frequency (94.8%) than cows with low antibody titers (between 25 and 200) (14.8%). Negative precolostrum calves (7/12) had postcolostrum N. caninum titers 2-8 times higher than their dams. Estimated horizontal transmission frequency was 51 and 47%, based on differences of seroprevalences in calves and dams, and on the seroconversion of 9/19 negative precolostrum female calves when retested at 7 months, respectively. Average N. caninum titers of cows at breeding and calving were 120.6 and 320.9, respectively. Cows with a high titer at breeding had a high titer at calving. Therefore, N. caninum IFAT titers at breeding and calving could potentially be used as predictors of vertical transmission.
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Diagnosis of Sarcocystis Cruzi, Neospora caninum, and Toxoplasma gondii infections in cattle
Parasitology Research, 2008Co-Authors: G. Moré, W. Basso, D. Bacigalupe, M. C. Venturini, L. VenturiniAbstract:The aim of the study was to diagnose Sarcocystis sp. infections in cattle and to detect coinfections by Toxoplasma gondii and/or Neospora caninum . Blood, diaphragm, esophagus, and myocardium from 90 beef cattle from Argentina were collected. Histopathological, immunohistochemical, polymerase chain reaction assays, and direct microscopical examination were carried out. Sarcocysts from myocardium were measured and counted. Indirect fluorescent antibody test (IFAT) for the three protozoans was performed. Sarcocystis Cruzi sarcocysts were found in 100% of myocardium samples. Sarcocysts per gram ranged from 8 to 380 with higher values found in adult cattle ( p
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diagnosis of Sarcocystis Cruzi neospora caninum and toxoplasma gondii infections in cattle
Parasitology Research, 2008Co-Authors: Gaston More, W. Basso, D. Bacigalupe, M. C. Venturini, L. VenturiniAbstract:The aim of the study was to diagnose Sarcocystis sp. infections in cattle and to detect coinfections by Toxoplasma gondii and/or Neospora caninum. Blood, diaphragm, esophagus, and myocardium from 90 beef cattle from Argentina were collected. Histopathological, immunohistochemical, polymerase chain reaction assays, and direct microscopical examination were carried out. Sarcocysts from myocardium were measured and counted. Indirect fluorescent antibody test (IFAT) for the three protozoans was performed. Sarcocystis Cruzi sarcocysts were found in 100% of myocardium samples. Sarcocysts per gram ranged from 8 to 380 with higher values found in adult cattle (p < 0.001). T. gondii and N. caninum were not detected by immunohistochemistry. T. gondii DNA was found in myocardium of 2/20 seropositive animals, while N. caninum DNA was not found. Antibodies against S. Cruzi were detected in all samples, those against N. caninum in 73% and against T. gondii in 91% of the samples (IFAT titer ≥25). It is concluded that serology by IFAT is a suitable method to diagnose these protozoan infections due to its specific IgG detection; therefore, IFAT may be a useful tool to evaluate the impact of each protozoan infection in coinfected animals.
Jitender P. Dubey - One of the best experts on this subject based on the ideXlab platform.
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Sarcocystis heydorni, n. sp. (Apicomplexa: Sarcocystidae) with cattle (Bos taurus) and human (Homo sapiens) cycle
Parasitology Research, 2015Co-Authors: Jitender P. Dubey, Rafael Calero-bernal, Erna Wilpe, Shiv Kumar Verma, Ronald FayerAbstract:Cattle ( Bos taurus ) are intermediate hosts for four species of Sarcocystis , namely Sarcocystis Cruzi , Sarcocystis hirsuta , Sarcocystis hominis , and Sarcocystis rommeli . Of these four species, mature sarcocysts of S. Cruzi are thin-walled (
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Sarcocystis Cruzi infection in wood bison (Bison bison athabascae)
Veterinary parasitology, 2015Co-Authors: Rafael Calero-bernal, Shiv K. Verma, C. Tom Seaton, David R. Sinnett, Erin Ball, Detiger Dunams, Benjamin M. Rosenthal, Jitender P. DubeyAbstract:Endangered wood bison (Bison bison athabascae) is the largest terrestrial mammal in the American continent. Animal health is an important issue in their conservation, and Sarcocystis Cruzi may be a cause of clinical disease in Bovidae. Hearts of eight wood bison from Alaska, USA were examined for sarcocysts by histology, transmission electron microscopy, pepsin digestion, and molecularly. Sarcocystis bradyzoites were found in pepsin digests of all eight and sarcocysts were found in histologic sections of myocardium of four bison. Sarcocysts were thin-walled and ultrastructurally consistent with S. Cruzi. Characterization of DNA obtained from lysis of pepsin liberated bradyzoites by PCR-RFLP and subsequent phylogenetic analyses matched with that previously reported for S. Cruzi infecting cattle in the USA. Collectively, data indicate that wood bison is a natural intermediate host for S. Cruzi.
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SPECIFIC DETECTION OF NEOSPORA CANINUM OOCYSTS IN FECAL SAMPLES FROM EXPERIMENTALLY-INFECTED DOGS USING THE POLYMERASE CHAIN REACTION
The Journal of parasitology, 2001Co-Authors: Dolores E. Hill, Mark C. Jenkins, Susan Liddell, Jitender P. DubeyAbstract:Neospora caninum oocysts, passed in the feces of a definitive host (dog), were isolated, and genomic DNA was extracted. A polymerase cahin reaction (PCR) targeting the N. caninum-specific Nc 5 genomic sequence was performed using the isolated DNA. A synthesized competitor molecule containing part of the Nc 5 sequence was included in the assay as a check against false-negative PCR results and to quantify N. caninum oocyst DNA in fecal samples. A standard curve of the ratio of fluorescence intensity of PCR-amplified competitor to that of oocyst DNA was constructed to compare oocyst equivalents from fecal samples containing unknown numbers of N. caninum oocysts and to assess the sensitivity of the assay. The specificity of the assay was determined using the Nc 5–specific primers in PCR assays against other parasites likely to be found in canine feces. Genomic DNA sequences from the canine coccidians Hammondia heydorni, Cryptosporidium parvum, Sarcocystis Cruzi, S. tenella, and Isospora ohioensis and the cani...
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Meningoencephalitis in capercaillie (Tetrao urogallus L.) caused by a Sarcocystis-like organism.
Journal of zoo and wildlife medicine : official publication of the American Association of Zoo Veterinarians, 1997Co-Authors: Gustafsson K, Jitender P. Dubey, Book M, Uggla AAbstract:A nonsuppurative meningoencephalitis, previously presumed to be toxoplasmosis, was found in 53 capercaillies (Tetrao urogallus L.) examined at necropsy at the National Veterinary Institute, Uppsala, Sweden, between 1966 and 1985. Pronounced meningitis and encephalitis with perivascular cuffs of mononuclear inflammatory cells as well as focal gliosis were prominent histopathologic findings. Protozoa were frequently associated with these lesions. Ultrastructurally, the protozoa appeared to divide by endopolygeny, and merozoites had no rhoptries. Organisms from all 12 birds subjected to Sarcocystis Cruzi immunohistochemical staining reacted positively but did not react to Toxoplasma gondii antiserum. The agent was, therefore, assigned to the family Sarcocystidae and was probably more closely related to species of the genus Sarcocystis than to T. gondii.
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Serological evidence implicating Neospora species as a cause of abortion in British cattle.
The Veterinary record, 1994Co-Authors: Alexander J. Trees, F. Guy, Jc Low, L Roberts, D. Buxton, Jitender P. DubeyAbstract:By means of an immunofluorescence antibody test (IFAT), using in vitro cultured parasites as antigen, antibodies to Neospora species at titres > or = 1/1280 were found in 11 of 120 Scottish cattle that had recently aborted but in only one of 97 cattle from herds in which there had been no recent abortions (P or = 1/640 in the IFAT of convalescent sera from cattle infected experimentally with Toxoplasma gondii, Sarcocystis Cruzi, Eimeria bovis, E alabamensis, Cryptosporidium parvum and Babesia divergens. These results demonstrate that Neospora species infection occurs commonly in aborting cattle in Britain, and that the IFAT may be a useful tool for investigating the infection.
