VTechWorks staff will be away for the Thanksgiving holiday beginning at noon on Wednesday, November 27, through Friday, November 29. We will resume normal operations on Monday, December 2. Thank you for your patience.

Browsing by Author "Rosenthal, B. M."

Now showing 1 - 8 of 8
  • Thumbnail Image
    Besnoitia oryctofelisi n. sp (Protozoa : Apicomplexa) from domestic rabbits
    Dubey, Jitender P.; Sreekumar, C.; Lindsay, David S.; Hill, D.; Rosenthal, B. M.; Venturini, L.; Venturini, M. C.; Greiner, E. C. (Cambridge University Press, 2003-06)
    A species of Besnoitia from naturally infected rabbits from Argentina was propagated experimentally in mice, gerbils, rabbits, cats, and cell cultures. Cats fed tissue cysts from rabbits shed oocysts with a prepatent period of nine to 13 days. Sporulated oocysts were infective to gerbils, rabbits, outbred Swiss Webster and interferon gamma gene knockout mice. Bradyzoites were infective orally to gerbils and cats. Tachyzoites were successfully cultivated and maintained in vitro in bovine monocytes and African green monkey kidney cells. Schizonts were seen in the lamina propria of the small intestine of cats fed tissue cysts; the largest ones measured 52 x 45 mum. Schizonts were also present in mesenteric lymph nodes, livers, and other extra-intestinal organs of cats fed tissue cysts. Oocysts were 10-14 x 10-13 mum in size. This rabbit-derived species of Besnoitia resembled B. darlingi of the North American opossum, Didelphis virginiana with an opossum-cat cycle, but it was not transmissible to D. virginiana, and B. darlingi of opossums was not transmissible to rabbits. Based on biological, serological, antigenic, and molecular differences between the rabbit and the opossum Besnoitia, a new name, B. oryctofelisi is proposed for the parasite from domestic rabbits from Argentina.
  • Thumbnail Image
    Detection of Hammondia heydorni-like organisms and their differentiation from Neospora caninum using random-amplified polymorphic DNA-polymerase chain reaction
    Sreekumar, C.; Hill, Dolores E.; Fournet, V. M.; Rosenthal, B. M.; Lindsay, David S.; Dubey, Jitender P. (American Society of Parasitology, 2003-10)
    Neospora caninum and Hammondia heydorni are morphologically and phylogenetically related coccidians that are found in dogs. New diagnostic genetic loci, based on random-amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) were developed to aid in the detection of H. heydorni like parasites and to discriminate them from N. caninum and other related coccidians of dogs. On the basis of the data obtained from 5 random decamers, H. heydorni (Manhattan-1) and N. caninum (NC1) were characterized by distinct banding patterns (similarity index = 0.068). High-stringency PCR assays were developed from the sequences of 2 cloned hands (GenBank BZ592549 and BZ592593), uniquely amplified from H. heydorni. Interestingly, using these primers, PCR amplification was achieved only from 2 of the 5 isolates presumed to represent H. heydorni. The same result was obtained From these 5 isolates using a recently described PCR assay directed to the H. heydorni internal transcribed spacer-1. It is concluded that H. heydorni and N. caninum are genetically distinct and that such tools may be useful for more detailed characterization of the diversity of related parasites occurring in dogs.
  • Thumbnail Image
    Isolates of Sarcocystis falcatula-like organisms from South American opossums Didelphis marsupialis and Didelphis albiventris from Sao Paulo, Brazil
    Dubey, Jitender P.; Lindsay, David S.; Rosenthal, B. M.; Kerber, C. E.; Kasai, N.; Pena, H. F. J.; Kwok, O. C. H.; Shen, S. K.; Gennari, S. M. (American Society of Parasitology, 2001-12)
    Isolates of Sarcocystis falcatula-like organisms from South American opossums were characterized based on biological and morphological criteria. Sporocysts from intestinal scrapings of 1 Didelphis marsupialis and 8 Didelphis albiventris from Sao Paulo, Brazil. were fed to captive budgerigars (Melopsittacus undulants). Budgerigars fed sporocysts from all 9 isolates became ill and S. falcatula-like schizonts were identified in sections of their lungs by immunohistochemical staining. Sarcocystis falcatula-like organisms were cultured from lungs of budgerigars fed sporocysts from D. marsupialis and from lungs of budgerigars fed sporocysts from 3 of 8 D. albiventris. The 33/54 locus amplified by polymerase chain reaction from culture-derived merozoites contained both a HinfI endonuclease recognition site previously suggested to diagnose S. falcatula and a DraI site thought to diagnosed S. neurona. Development of the isolate from D. marsupialis was studied in cell cultured its schizonts divided by endopolygeny, leaving a residual body. Morphological and genetic variation differentiated this Sarcocystis isolate originating in D. marsupialis from the Cornell 1 isolate of S. falcatula. This is the first report of a S. falcatula infection in the South American opossum. D. marsupialis.
  • Thumbnail Image
    Sarcocystis Jamaicensis N. Sp., From Red-Tailed Hawks (Buteo Jamaicensis) Definitive Host and Ifn-Gamma Gene Knockout Mice as Experimental Intermediate Host
    Verma, S. K.; von Dohlen, Alexa Rosypal; Mowery, J. D.; Scott, D.; Rosenthal, B. M.; Dubey, Jitender P.; Lindsay, David S. (2017-10)
    Here, we report a new species of Sarcocystis with red-tailed hawk (RTH, Buteo jamaicensis) as the natural definitive host and IFN-gamma gene knockout (KO) mice as an experimental intermediate host in which sarcocysts form in muscle. Two RTHs submitted to the Carolina Raptor Center, Huntersville, North Carolina, were euthanized because they could not be rehabilitated and released. Fully sporulated 12.5 x 9.9-mu m sized sporocysts were found in intestinal scrapings of both hawks. Sporocysts were orally fed to laboratory-reared outbred Swiss Webster mice (SW, Mus musculus) and also to KO mice. The sporocysts were infective for KO mice but not for SW mice. All SW mice remained asymptomatic, and neither schizonts nor sarcocysts were found in any SW mice euthanized on days 54, 77, 103 (n = 2) or 137 post-inoculation (PI). The KO mice developed neurological signs and were necropsied between 52 to 68 days PI. Schizonts/merozoites were found in all KO mice euthanized on days 52, 55 (n = 3), 59, 61 (n = 2), 66, and 68 PI and they were confined to the brain. The predominant lesion was meningoencephalitis characterized by perivascular cuffs, granulomas, and necrosis of the neural tissue. The schizonts/merozoites were located in neural tissue and were apparently extravascular. Brain homogenates from infected KO mice were infective to KO mice by subcutaneous inoculation and when seeded on to CV-1 cells. Microscopic sarcocysts were found in skeletal muscles of 5 of 8 KO mice euthanized between 55-61 days PI. Only a few sarcocysts were detected. Sarcocysts were microscopic, up to 3.5 mm long. When viewed with light microscopy, the sarcocyst wall appeared thin (< 1 mu m thick) and smooth. By transmission electron microscopy, the sarcocyst wall classified as "type 1j'' (new designation). Molecular characterization using 18S rRNA, 28S rRNA, ITS-1, and cox1 genes revealed a close relationship with Sarcocystis microti and Sarcocystis glareoli; both species infect birds as definitive hosts. The parasite in the present study was biologically and molecularly different from species so far described in RTHs and we therefore propose a new species name, Sarcocystis jamaicensis n. sp.
  • Thumbnail Image
    Sarcocystis neurona infections in sea otter (Enhydra lutris): Evidence for natural infections with sarcocysts and transmission of infection to opossums (Didelphis virginiana)
    Dubey, Jitender P.; Rosypal, A. C.; Rosenthal, B. M.; Thomas, N. J.; Lindsay, David S.; Stanek, J. F.; Reed, S. M.; Saville, W. J. A. (American Society of Parasitology, 2001-12)
    Although Sarcocystis neurona has been identified in an array of terrestrial vertebrates, recent recognition of its capacity to infect marine mammals was unexpected. Here, sarcocysts from 2 naturally infected sea otters (Enhydra lutris) were characterized biologically, ultrastructurally, and genetically. DNA was extracted from frozen muscle of the first of these sea otters and was characterized as S. neurona by polymerase chain reation (PCR) amplification followed by restriction fragment length polymorphism analysis and sequencing. Sarcocysts from sea otter no. 1 were up to 350 mum long, and the villar protrusions on the sarcocyst wall were up to 1.3 mum long and up to 0.25 mum wide. The villar protrusions were tapered towards the villar tip. Ultrastructurally, sarcocysts were similar to S. neurona sarcocysts from the muscles of cats experimentally infected with S. neurona sporocysts, Skeletal muscles from a second sea otter failed to support PCR amplification of markers considered diagnostic for S. neurona but did induce the shedding of sporocysts when fed to a laboratory-raised opossum (Didelphis virginiana). Such sporocysts were subsequently fed to knockout mice for the interferon-gamma gene, resulting in infections with an agent identified as S. neurona on the basis of immunohistochemistry, serum antibodies, and diagnostic sequence detection. Thus, sea otters exposed to S. neurona may support the development of mature sarcocysts that are infectious to competent definitive hosts.
  • Thumbnail Image
    Sarcocystis Pantherophisi N. Sp., From Eastern Rat Snakes (Pantherophis Alleghaniensis) as Definitive Hosts and Interferon Gamma Gene Knockout Mice as Experimental Intermediate Hosts
    Verma, S. K.; Lindsay, David S.; Mowery, J. D.; Rosenthal, B. M.; Dubey, Jitender P. (2017-10)
    Here, we report a new species, Sarcocystis pantherophisi n. sp., with the Eastern rat snake (Pantherophis alleghaniensis) as natural definitive host and the interferon gamma gene knockout (KO) mouse as the experimental intermediate host. Sporocysts (n = 15) from intestinal contents of the snake were 10.838.9 lm. Sporocysts were orally infective to KO mice but not to laboratory-raised albino outbred house mice (Mus musculus). The interferon gamma KO mice developed schizont-associated neurological signs, and schizonts were cultivated in vitro from the brain. Mature sarcocysts were found in skeletal muscles of KO mice examined 41 days postinoculation (PI). Sarcocysts were slender, up to 70 lm wide and up to 3.5 mm long. By light microscopy, sarcocysts appeared thin-walled (, 1 lm) without projections. By transmission electron microscopy, the sarcocyst wall was a variant of "type 1'' (type 1i, new designation). The parasitophorous vacuolar membrane (pvm) had approximately 100-nm-wide3100-nm-long bleb-like evaginations interspersed with 100-nm-wide 3 650-nm-long elongated protrusions at irregular distances, and invaginations into the ground substance layer (gs) for a very short distance (6 nm). The gs was smooth, up to 500 nm thick, without tubules, and contained a few vesicles. Longitudinally cut bradyzoites at 54 days PI were bananashaped, 7.832.2 lm (n = 5). Molecular characterization using 18S rRNA, 28S rRNA, ITS-1, and cox1 genes indicated a close relationship with other Sarcocystis parasites that have snake-rodent life cycles. The parasite in the present study was molecularly and biologically similar to a previously reported isolate (designated earlier as Sarcocystis sp. ex Pantherophis alleghaniensis) from P. alleghaniensis, and it was structurally different from other Sarcocystis species so far described.
  • Thumbnail Image
    Sarcocystis Strixi N. Sp From a Barred Owl (Strix varia) Definitive Host and Interferon Gamma Gene Knockout Mice as Experimental Intermediate Host
    Verma, S. K.; von Dohlen, Alexa Rosypal; Mowery, J. D.; Scott, D.; Cerqueira-Cezar, Camila K.; Rosenthal, B. M.; Dubey, Jitender P.; Lindsay, David S. (2017-12)
    Here we report a new species of Sarcocystis with a barred owl (Strix varia) as the natural definitive host and interferon gamma gene knockout (KO) mice as an experimental intermediate host. A barred owl submitted to the Carolina Raptor Center, Huntersville, North Carolina, was euthanized because of paralysis. Fully sporulated 12.539.9 lm sporocysts were found in intestinal scrapings from the owl. Sporocysts from the barred owl were orally fed to 4 laboratory-reared outbred Swiss Webster (SW) (Mus musculus) and 8 KO mice. All mice remained asymptomatic. Microscopic sarcocysts were found in all 5 KO mice euthanized on day 32, 59, 120, 154, and 206 post- inoculation (PI), not in KO mice euthanized on day 4, 8, and 14 PI. Sarcocysts were not found in any SW mice euthanized on day 72, 120, 206, and 210 PI. Sarcocysts were microscopic, up to 70 lm wide. By light microscopy, the sarcocyst wall, 2 lm thick had undulating, flat to conical, protrusions of varying dimensions. Numerous sarcocysts were seen in the histological sections of tongue and skeletal muscles from the abdomen, limbs, and eye but not in the heart. By transmission electron microscopy, the sarcocyst wall was "type 1j.'' The ground substance layer (gs) was homogenous, up to 2 lm thick, with very fine granules, and a few vesicles concentrated toward the villar projections. No microtubules were seen in the gs. Longitudinally cut bradyzoites at 206 days PI were 7.8 3 2.2 lm. Based on molecular characterization using 18S rRNA, 28S rRNA, and cox1 genes and morphology of sarcocysts, the parasite in the present study was biologically and structurally different from species so far described, and we therefore propose a new species name, Sarcocystis strixi n. sp.
  • Thumbnail Image
    Sarcocysts of an unidentified species of Sarcocystis in the sea otter (Enhydra lutris)
    Dubey, Jitender P.; Lindsay, David S.; Rosenthal, B. M.; Thomas, N. J. (American Society of Parasitology, 2003-04)
    The number of Sarcocystis species that infect sea otters (Enhydra lutris) is unknown. Sea otter tissues were recently shown to harbor sarcocysts of S. neurona and of unidentified species of Sarcocystis. Whereas sarcocysts of S. neurona have walls 1-3 mum thick with type 9 villar protrusions, ultrastructure of a distinct thin-walled sarcocyst (0.5-0.7 mum thick) lacking villar protrusions, but instead exhibiting minute type I undulations on the sarcocyst wall, is described in this report. Parasites characterized from a sea otter infection were inferred to be related to, but distinct from, other species belonging to Sarcocystis, based on sequencing and phylogenetic analysis of a portion of the beta subunit of the plastid-encoded RNA polymerase gene.