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Ann M Rashmirraven - One of the best experts on this subject based on the ideXlab platform.

  • establishment of besnoitia darlingi from opossums Didelphis virginiana in experimental intermediate and definitive hosts propagation in cell culture and description of ultrastructural and genetic characteristics
    International Journal for Parasitology, 2002
    Co-Authors: J P Dubey, S S Black, Lora G. Rickard, C Sreekumar, S K Shen, D E Hill, Benjamin M Rosenthal, O C H Kwok, David S Lindsay, Ann M Rashmirraven
    Abstract:

    Abstract Besnoitia darlingi from naturally infected opossums ( Didelphis virginiana ) from Mississippi, USA, was propagated experimentally in mice, cats, and cell culture and was characterised according to ultrastructural, genetic, and life-history characteristics. Cats fed tissue cysts from opossums shed oocysts with a prepatent period of nine or 11 days. Oocysts, bradyzoites, or tachyzoites were infective to outbred and interferon-gamma gene knockout mice. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey cells and revived after an 18-month storage in liquid nitrogen. Schizonts were seen in the small intestinal lamina propria of cats fed experimentally-infected mouse tissues. These schizonts measured up to 45×25 μm and contained many merozoites. A few schizonts were present in mesenteric lymph nodes and livers of cats fed tissue cysts. Ultrastructurally, tachyzoites and bradyzoites of B . darlingi were similar to other species of Besnoitia . A close relationship to B . besnoiti and an even closer relationship to B . jellisoni was indicated for B . darlingi on the basis of the small subunit and ITS-1 portions of nuclear ribosomal DNA.

  • risk factors associated with the presence of sarcocystis neurona sporocysts in opossums Didelphis virginiana
    Veterinary Parasitology, 2001
    Co-Authors: L G Rickard, S S Black, Ann M Rashmirraven, G Hurst
    Abstract:

    Sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (EPM) in horse in the Americas. The only known definitive host for this parasite in the United States is the opossum (Didelphis virginiana); however, despite the importance of the disease, the epidemiology of the parasite in the definitive host is poorly understood. To begin addressing these data gaps, potential risk factors were evaluated for their association with the presence of sporocysts of S. neurona in opossums live-trapped in March 1999 and November 1999 to May 2000. Sporocysts of S. neurona were found in 19 of the 72 animals examined. Potential risk factors evaluated were locality, trap date, age, gender, the presence of young in the pouch of females, and body condition score. Variables that were associated with the presence of S. neurona sporocysts were used in logistic regression analysis. Of the factors examined, season and body condition score were associated with increased odds of an animal harboring sporocysts.

  • prevalence of sarcocystis neurona sporocysts in opossums Didelphis virginiana from rural mississippi
    Veterinary Parasitology, 2001
    Co-Authors: S S Black, S K Shen, L G Rickard, B M Rosenthal, O C Kwok, G Hurst, Ann M Rashmirraven
    Abstract:

    Abstract Sarcocystis species sporocysts were found in intestinal scrapings from 24 of 72 opossums ( Didelphis virginiana ) from rural Mississippi. The number of sporocysts in each opossum varied from a few ( Sarcocystis neurona infections by feeding to gamma-interferon knockout (KO) mice. S. neurona was detected in the brains of KO mice fed sporocysts from 19 opossums by immunohistochemical staining with anti -S. neurona specific polyclonal rabbit serum, and by in vitro culture from the brains of KO mice fed sporocysts. The isolates of S. neurona from opossums were designated SN16-OP to SN34-OP. Merozoites from 17 of 19 isolates tested at the 25/396 locus were identical to previously described S. neurona isolates from horses. The high prevalence of S. neurona sparocysts in D. virginiana suggests that this opossum constitutes an ample reservoir of infection in the southern United States.

J P Dubey - One of the best experts on this subject based on the ideXlab platform.

  • prevalence of antibodies to trypanosoma cruzi toxoplasma gondii encephalitozoon cuniculi sarcocystis neurona besnoitia darlingi and neospora caninum in north american opossums Didelphis virginiana from southern louisiana
    Journal of Parasitology, 2010
    Co-Authors: Alice E Houk, J P Dubey, David G Goodwin, Anne M Zajac, Stephen C Barr, David S Lindsay
    Abstract:

    Abstract We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoans of veterinary importance (Neospora caninum, Sarcocystis neurona, and Besnoitia darlingi) in a population of North American opossums (Didelphis virginiana) from Louisiana. Samples from 30 opossums were collected as part of a survey for T. cruzi in Louisiana. Frozen sera from these 30 opossums were examined using an indirect immunofluorescent antibody test (IFAT) against in vitro-produced antigenic stages of these protozoans. Additionally, 24 of the 30 samples were examined using hemoculture, and all 30 were examined in the modified direct agglutination test (MAT) for antibodies to To. gondii. The prevalences of reactive IFAT samples were as follows: 60% for T. cruzi, 27% for To. gondii, 23% for E. cuniculi, 17% for S. neurona, 47% for B. darlingi, and 0% for N. caninum. Hemoculture revealed that 16 (67%) of 24 samples were positive for T. cruz...

  • establishment of besnoitia darlingi from opossums Didelphis virginiana in experimental intermediate and definitive hosts propagation in cell culture and description of ultrastructural and genetic characteristics
    International Journal for Parasitology, 2002
    Co-Authors: J P Dubey, S S Black, Lora G. Rickard, C Sreekumar, S K Shen, D E Hill, Benjamin M Rosenthal, O C H Kwok, David S Lindsay, Ann M Rashmirraven
    Abstract:

    Abstract Besnoitia darlingi from naturally infected opossums ( Didelphis virginiana ) from Mississippi, USA, was propagated experimentally in mice, cats, and cell culture and was characterised according to ultrastructural, genetic, and life-history characteristics. Cats fed tissue cysts from opossums shed oocysts with a prepatent period of nine or 11 days. Oocysts, bradyzoites, or tachyzoites were infective to outbred and interferon-gamma gene knockout mice. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey cells and revived after an 18-month storage in liquid nitrogen. Schizonts were seen in the small intestinal lamina propria of cats fed experimentally-infected mouse tissues. These schizonts measured up to 45×25 μm and contained many merozoites. A few schizonts were present in mesenteric lymph nodes and livers of cats fed tissue cysts. Ultrastructurally, tachyzoites and bradyzoites of B . darlingi were similar to other species of Besnoitia . A close relationship to B . besnoiti and an even closer relationship to B . jellisoni was indicated for B . darlingi on the basis of the small subunit and ITS-1 portions of nuclear ribosomal DNA.

  • prevalence of sarcocystis species sporocysts in wild caught opossums Didelphis virginiana
    Journal of Parasitology, 2000
    Co-Authors: J P Dubey
    Abstract:

    Sarcocystis sporocysts were found in intestinal scrapings from 24 (54.5%) of 44 opossums (Didelphis virginiana). The number of sporocysts varied from a few (<10,000) to 245 million. Sporocysts from 23 of 24 opossums were fed to captive budgerigars (Melopsittacus undulatas), and the inocula from 21 opossums were infective, indicating the presence of Sarcocystis falcatula. Sporocysts from 24 opossums were fed to gamma-interferon-knockout (KO) or nude mice; inocula from 14 opossums were infective to mice. Sarcocystis neurona was detected in tissues of KO mice by specific staining with anti-S. neurona antibodies, and the parasite was cultured in vitro from the brains of KO mice fed sporocysts from 8 opossums. Sarcocystis speeri was identified by specific staining with anti-S. speeri antibodies in tissues of KO mice fed inocula from 8 opossums; 3 opossums had mixed S. neurona and S. speeri infections. Thus, the prevalences of sporocysts of different species of Sarcocystis in opossums were: S. falcatula 21 of 4...

  • sarcocystis speeri n sp protozoa sarcocystidae from the opossum Didelphis virginiana
    Journal of Parasitology, 1999
    Co-Authors: J P Dubey
    Abstract:

    The North American opossum (Didelphis virginiana) is host to at least 3 species of Sarcocystis: Sarcocystisfalcatula, Sarcocystis neurona, and a recently recognized Sarcocystis sp. A new name, Sarcocystis speeri, is proposed for the third unnamed Sarcocystis. Immunodeficient mice are an experimental intermediate host for S. speeri. Sarcocystis speeri sporocysts are 12-15 x 8-10 microm in size, and its schizonts are found in many organs of mice. Sarcocysts of S. speeri are found in skeletal muscles and they are up to 5 mm long and filiform. By light microscopy, the sarcocyst wall is thin (<1 microm thick); ultrastructurally, the cyst wall is up to 1.8 microm thick and has characteristic steeple-shaped villar protrusions surmounted by a spire. Sarcocystis speeri schizonts are morphologically and antigenically distinct from schizonts of S. neurona, and S. speeri sporocysts were not infective to budgerigars (Melopsittacus undulatus).

  • isolation in immunodeficient mice of sarcocystis neurona from opossum Didelphis virginiana faeces and its differentiation from sarcocystis falcatula
    International Journal for Parasitology, 1998
    Co-Authors: J P Dubey
    Abstract:

    Sarcocystis neurona was isolated in nude mice and gamma-interferon knockout mice fed sporocysts from faeces of naturally infected opossums (Didelphis virginiana). Mice fed sporocysts became lethargic and developed encephalitis. Protozoa were first found in the brain starting 21 days post-inoculation. Sarcocystis neurona was recovered in cell culture from the homogenate of liver, spleen and brain of a nude mouse 11 days after feeding sporocysts. The protozoa in mouse brain and in cell culture multiplied by schizogony and mature schizonts often had a residual body. Sarcocystis falcatula, which has an avian-opossum cycle, was not infective to nude or knockout mice. Protozoa were not found in tissues of nude mice or knockout mice after subcutaneous injection with culture-derived S. falcatula merozoites and sporocysts from the faeces of opossums presumed to contain only S. falcatula. Results demonstrate that S. neurona is distinct from S. falcatula, and that opossums are hosts for both species.

David S Lindsay - One of the best experts on this subject based on the ideXlab platform.

  • prevalence of antibodies to trypanosoma cruzi toxoplasma gondii encephalitozoon cuniculi sarcocystis neurona besnoitia darlingi and neospora caninum in north american opossums Didelphis virginiana from southern louisiana
    Journal of Parasitology, 2010
    Co-Authors: Alice E Houk, J P Dubey, David G Goodwin, Anne M Zajac, Stephen C Barr, David S Lindsay
    Abstract:

    Abstract We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoans of veterinary importance (Neospora caninum, Sarcocystis neurona, and Besnoitia darlingi) in a population of North American opossums (Didelphis virginiana) from Louisiana. Samples from 30 opossums were collected as part of a survey for T. cruzi in Louisiana. Frozen sera from these 30 opossums were examined using an indirect immunofluorescent antibody test (IFAT) against in vitro-produced antigenic stages of these protozoans. Additionally, 24 of the 30 samples were examined using hemoculture, and all 30 were examined in the modified direct agglutination test (MAT) for antibodies to To. gondii. The prevalences of reactive IFAT samples were as follows: 60% for T. cruzi, 27% for To. gondii, 23% for E. cuniculi, 17% for S. neurona, 47% for B. darlingi, and 0% for N. caninum. Hemoculture revealed that 16 (67%) of 24 samples were positive for T. cruz...

  • lack of sarcocystis neurona antibody response in virginia opossums Didelphis virginiana fed sarcocystis neurona infected muscle tissue
    Journal of Parasitology, 2006
    Co-Authors: M.a Cheadle, David S Lindsay, Ellis C. Greiner
    Abstract:

    Serum was collected from laboratory-reared Virginia opossums (Didelphis virginiana) to determine whether experimentally infected opossums shedding Sarcocystis neurona sporocysts develop serum antibodies to S. neurona merozoite antigens. Three opossums were fed muscles from nine-banded armadillos (Dasypus novemcinctus), and 5 were fed muscles from striped skunks (Mephitis mephitis). Serum was also collected from 26 automobile-killed opossums to determine whether antibodies to S. neurona were present in these opossums. Serum was analyzed using the S. neurona direct agglutination test (SAT). The SAT was modified for use with a filter paper collection system. Antibodies to S. neurona were not detected in any of the serum samples from opossums, indicating that infection in the opossum is localized in the small intestine. Antibodies to S. neurona were detected in filter-paper-processed serum samples from 2 armadillos naturally infected with S. neurona.

  • prevalence of agglutinating antibodies to toxoplasma gondii in striped skunks mephitis mephitis opossums Didelphis virginiana and raccoons procyon lotor from connecticut
    Journal of Parasitology, 2006
    Co-Authors: Sheila M Mitchell, Dennis J. Richardson, David S Lindsay
    Abstract:

    The prevalence of agglutinating antibodies to Toxoplasma gondii was examined in striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and raccoons (Procyon lotor) from 8 cities in Connecticut. Ten (42%) of the 24 striped skunks, 2 of 7 (29%) opossums, and 12 of 12 (100%) raccoons were positive at dilutions of 1:50 or greater. These results suggest that T. gondii is prevalent in the environment, or prey items, or both, of these omnivores in Connecticut.

  • establishment of besnoitia darlingi from opossums Didelphis virginiana in experimental intermediate and definitive hosts propagation in cell culture and description of ultrastructural and genetic characteristics
    International Journal for Parasitology, 2002
    Co-Authors: J P Dubey, S S Black, Lora G. Rickard, C Sreekumar, S K Shen, D E Hill, Benjamin M Rosenthal, O C H Kwok, David S Lindsay, Ann M Rashmirraven
    Abstract:

    Abstract Besnoitia darlingi from naturally infected opossums ( Didelphis virginiana ) from Mississippi, USA, was propagated experimentally in mice, cats, and cell culture and was characterised according to ultrastructural, genetic, and life-history characteristics. Cats fed tissue cysts from opossums shed oocysts with a prepatent period of nine or 11 days. Oocysts, bradyzoites, or tachyzoites were infective to outbred and interferon-gamma gene knockout mice. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey cells and revived after an 18-month storage in liquid nitrogen. Schizonts were seen in the small intestinal lamina propria of cats fed experimentally-infected mouse tissues. These schizonts measured up to 45×25 μm and contained many merozoites. A few schizonts were present in mesenteric lymph nodes and livers of cats fed tissue cysts. Ultrastructurally, tachyzoites and bradyzoites of B . darlingi were similar to other species of Besnoitia . A close relationship to B . besnoiti and an even closer relationship to B . jellisoni was indicated for B . darlingi on the basis of the small subunit and ITS-1 portions of nuclear ribosomal DNA.

S S Black - One of the best experts on this subject based on the ideXlab platform.

  • establishment of besnoitia darlingi from opossums Didelphis virginiana in experimental intermediate and definitive hosts propagation in cell culture and description of ultrastructural and genetic characteristics
    International Journal for Parasitology, 2002
    Co-Authors: J P Dubey, S S Black, Lora G. Rickard, C Sreekumar, S K Shen, D E Hill, Benjamin M Rosenthal, O C H Kwok, David S Lindsay, Ann M Rashmirraven
    Abstract:

    Abstract Besnoitia darlingi from naturally infected opossums ( Didelphis virginiana ) from Mississippi, USA, was propagated experimentally in mice, cats, and cell culture and was characterised according to ultrastructural, genetic, and life-history characteristics. Cats fed tissue cysts from opossums shed oocysts with a prepatent period of nine or 11 days. Oocysts, bradyzoites, or tachyzoites were infective to outbred and interferon-gamma gene knockout mice. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey cells and revived after an 18-month storage in liquid nitrogen. Schizonts were seen in the small intestinal lamina propria of cats fed experimentally-infected mouse tissues. These schizonts measured up to 45×25 μm and contained many merozoites. A few schizonts were present in mesenteric lymph nodes and livers of cats fed tissue cysts. Ultrastructurally, tachyzoites and bradyzoites of B . darlingi were similar to other species of Besnoitia . A close relationship to B . besnoiti and an even closer relationship to B . jellisoni was indicated for B . darlingi on the basis of the small subunit and ITS-1 portions of nuclear ribosomal DNA.

  • risk factors associated with the presence of sarcocystis neurona sporocysts in opossums Didelphis virginiana
    Veterinary Parasitology, 2001
    Co-Authors: L G Rickard, S S Black, Ann M Rashmirraven, G Hurst
    Abstract:

    Sarcocystis neurona is the most important cause of equine protozoal myeloencephalitis (EPM) in horse in the Americas. The only known definitive host for this parasite in the United States is the opossum (Didelphis virginiana); however, despite the importance of the disease, the epidemiology of the parasite in the definitive host is poorly understood. To begin addressing these data gaps, potential risk factors were evaluated for their association with the presence of sporocysts of S. neurona in opossums live-trapped in March 1999 and November 1999 to May 2000. Sporocysts of S. neurona were found in 19 of the 72 animals examined. Potential risk factors evaluated were locality, trap date, age, gender, the presence of young in the pouch of females, and body condition score. Variables that were associated with the presence of S. neurona sporocysts were used in logistic regression analysis. Of the factors examined, season and body condition score were associated with increased odds of an animal harboring sporocysts.

  • prevalence of sarcocystis neurona sporocysts in opossums Didelphis virginiana from rural mississippi
    Veterinary Parasitology, 2001
    Co-Authors: S S Black, S K Shen, L G Rickard, B M Rosenthal, O C Kwok, G Hurst, Ann M Rashmirraven
    Abstract:

    Abstract Sarcocystis species sporocysts were found in intestinal scrapings from 24 of 72 opossums ( Didelphis virginiana ) from rural Mississippi. The number of sporocysts in each opossum varied from a few ( Sarcocystis neurona infections by feeding to gamma-interferon knockout (KO) mice. S. neurona was detected in the brains of KO mice fed sporocysts from 19 opossums by immunohistochemical staining with anti -S. neurona specific polyclonal rabbit serum, and by in vitro culture from the brains of KO mice fed sporocysts. The isolates of S. neurona from opossums were designated SN16-OP to SN34-OP. Merozoites from 17 of 19 isolates tested at the 25/396 locus were identical to previously described S. neurona isolates from horses. The high prevalence of S. neurona sparocysts in D. virginiana suggests that this opossum constitutes an ample reservoir of infection in the southern United States.

Ellis C. Greiner - One of the best experts on this subject based on the ideXlab platform.

  • lack of sarcocystis neurona antibody response in virginia opossums Didelphis virginiana fed sarcocystis neurona infected muscle tissue
    Journal of Parasitology, 2006
    Co-Authors: M.a Cheadle, David S Lindsay, Ellis C. Greiner
    Abstract:

    Serum was collected from laboratory-reared Virginia opossums (Didelphis virginiana) to determine whether experimentally infected opossums shedding Sarcocystis neurona sporocysts develop serum antibodies to S. neurona merozoite antigens. Three opossums were fed muscles from nine-banded armadillos (Dasypus novemcinctus), and 5 were fed muscles from striped skunks (Mephitis mephitis). Serum was also collected from 26 automobile-killed opossums to determine whether antibodies to S. neurona were present in these opossums. Serum was analyzed using the S. neurona direct agglutination test (SAT). The SAT was modified for use with a filter paper collection system. Antibodies to S. neurona were not detected in any of the serum samples from opossums, indicating that infection in the opossum is localized in the small intestine. Antibodies to S. neurona were detected in filter-paper-processed serum samples from 2 armadillos naturally infected with S. neurona.

  • prevalence and site specificity of sarcocystis greineri sarcocysts in virginia opossum Didelphis virginiana in florida
    Journal of Parasitology, 2002
    Co-Authors: K L Baird, M.a Cheadle, Ellis C. Greiner
    Abstract:

    Sarcocysts of Sarcocystis greineri in the Virginia opossum (Didelphis virginiana) were observed for documenting sarcocyst prevalence, seasonal prevalence, and muscle specificity. Characteristics of sarcocysts found in striated muscle were recorded, as were light microscopy measurements. Overall prevalence of sarcocysts in striated muscle was 10.0% (24/240). No statistical difference (P = 0.156) in prevalence was detected between summer (13.1%; 16/122) and fall (6.7%; 8/118). Sarcocysts were found in muscles of the diaphragm, leg, breast, tongue, back, and esophagus. Diaphragm had the highest specificity of 72.7% (8/11), which was significantly different (P = 0.05) when compared with tongue and esophagus at 16.6% (1/6). Breast and leg muscle had a specificity of sarcocysts of 54.5% (6/11), whereas 27.2% (3/11) of back muscles contained sarcocysts.

  • sporocyst size of isolates of sarcocystis shed by the virginia opossum Didelphis virginiana
    Veterinary Parasitology, 2001
    Co-Authors: M.a Cheadle, J B Dame, Ellis C. Greiner
    Abstract:

    Abstract The Virginia opossum (Didelphis virginiana) is a definitive host for multiple Sarcocystis species including Sarcocystis neurona, one of the causative agents of equine protozoal myeloencephalitis (EPM), a severe, neuromuscular disease of horses. Size and morphologic characteristics of isolates of Sarcocystis shed by the opossum were examined to determine if differences were useful in discriminating between the isolates and/or species. Collections of sporocysts from 17 opossums were molecularly characterized and measured using an ocular micrometer. The mean sporocyst size of isolates of S. neurona was 10.7 μm ×7.0 μm , Sarcocystis falcatula 11.0 μm ×7.1 μm , Sarcocystis speeri 12.2 μm ×8.8 μm , 1085-like isolate 10.9 μm ×6.8 μm , and 3344-like isolate 19.4 μm ×10.5 μm . The length and width of S. speeri were statistically different (p