RESUMO
A new species, Sarcocystis lindsayi n. sp., is proposed for a parasite resembling Sarcocystis falcatula. It was obtained from the lungs and muscles of budgerigars (Melopsittacus undulatus) fed sporocysts from a naturally-infected South American opossum, Didelphis albiventris, from Jaboticabal, Brazil. Sarcocysts of S. lindsayi n. sp. in budgerigars are microscopic, up to 600 microm long and up to 50 microm wide. The cyst wall is up to 2 microm thick. Ultrastructurally, the sarcocyst wall consists of numerous slender villar protrusions (up to 2.0 microm long and up to 0.3 microm wide), each with a stylet at its tip. Schizonts in cell culture divide by endopolygeny leaving a residual body. Sporocysts are approximately 12 x 7 microm. The parasite is genetically distinct from other organisms that also cycle between opossums and avian species and resemble S. falcatula. Diagnostic genetic variation has been observed in the nuclear large subunit ribosomal RNA gene, the internal transcribed spacer (ITS-1), and each of two other genetic loci. Although the structure of the sarcocyst wall may not provide sufficient grounds for differential diagnosis, several other attributes including schizont morphology and genetic variation at each of these genetic loci permit identification of S. lindsayi n. sp.. Natural intermediate hosts for S. lindsayi n. sp. are not known, and fuller characterization of these and other Sarcocystis species would benefit from experimental avian hosts that are more permissive to the maturation of sarcocysts.
Assuntos
Gambás/parasitologia , Sarcocystis/classificação , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , Doenças das Aves/parasitologia , Brasil , DNA de Protozoário/análise , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Papagaios/parasitologia , Filogenia , RNA Ribossômico/genética , Sarcocystis/patogenicidade , Sarcocystis/ultraestrutura , Sarcocistose/parasitologia , Análise de Sequência de DNARESUMO
Sarcocystis speeri Dubey and Lindsay, 1999 from the South American opossum Didelphis albiventris was successfully transmitted to the North American opossum Didelphis virginiana. Sporocysts from a naturally infected D. albiventris from Argentina were fed to 2 gamma-interferon knockout (KO) mice. The mice were killed 64 and 71 days after sporocyst feeding (DAF). Muscles containing sarcocysts from the KO mouse killed 71 DAF were fed to a captive D. virginiana; this opossum shed sporocysts 11 days after ingesting sarcocysts. Sporocysts from D. virginiana were fed to 9 KO mice and 4 budgerigars (Melopsittacus undulatus). Schizonts, sarcocysts, or both of S. speeri were found in tissues of all 7 KO mice killed 29-85 DAF; 2 mice died 39 and 48 DAF were not necropsied. Sarcocystis stages were not found in tissues of the 4 budgerigars fed S. speeri sporocysts and killed 35 DAE These results indicate that S. speeri is distinct from Sarcocystis falcatula and Sarcocystis neurona, and that S. speeri is present in both D. albiventris and D. virginiana.
Assuntos
Gambás/parasitologia , Sarcocystis/patogenicidade , Sarcocistose/veterinária , Animais , Argentina , Encéfalo/parasitologia , Fezes/parasitologia , Interferon gama/genética , Intestino Delgado/parasitologia , Fígado/parasitologia , Camundongos , Camundongos Knockout , Microscopia Eletrônica , Músculo Esquelético/parasitologia , América do Norte , Papagaios , Sarcocystis/ultraestrutura , Sarcocistose/transmissãoRESUMO
Sarcocystis sporocysts from the intestines of 2 opossums (Didelphis albiventris) from Argentina were fed to gamma-interferon knockout (KO) and nude mice. Protozoal schizonts were seen in brain, liver, spleen, and adrenal glands of mice examined 33-64 days after feeding sporocysts. Sarcocysts were seen in skeletal muscles of KO mice 34-71 days after feeding sporocysts. Schizonts and sarcocysts were structurally similar to Sarcocystis speeri Dubey and Lindsay, 1999 seen in mice fed sporocysts from the North American opossum Didelphis virginiana from the United States.
Assuntos
Enteropatias Parasitárias/veterinária , Gambás/parasitologia , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , Argentina , Feminino , Cavalos , Interações Hospedeiro-Parasita , Enteropatias Parasitárias/parasitologia , Enteropatias Parasitárias/transmissão , Intestino Delgado/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Nus , Músculo Esquelético/parasitologia , Sarcocystis/fisiologia , Sarcocystis/ultraestrutura , Sarcocistose/parasitologia , Sarcocistose/transmissãoAssuntos
Hidrocortisona/farmacologia , Lipopolissacarídeos/farmacologia , Malária/imunologia , Mycobacterium bovis/imunologia , Plasmodium berghei/imunologia , Animais , Antimaláricos/farmacologia , Combinação de Medicamentos/farmacologia , Imunidade Celular , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos , Pirimetamina/farmacologia , Sulfadoxina/farmacologiaRESUMO
The prevalence of chloroquine-resistant falciparum malaria was determined for humans living at 28 different sites in the Brazilian Amazon. Blood samples obtained from each patient were defibrinated, placed in vials containing 0.5% glucose and or chloroquine and incubated for 24 hours at 39-40 degrees C without agitation. In vitro sensitivity of the parasite to four different concentrations of chloroquine was determined for each sample. After 24 hours of incubation, trophozoites of Plasmodium falciparum developed to schizonts in all control cultures (no chloroquine) as well as in 80.6, 48.4, 11.8 and 7.5% of the cultures containing 0.5, 1.0, 2.0, and 3.0 nmol chloroquine/ml blood, respectively. Chloroquine-resistant P. falciparum was found in blood samples from all 28 locations, indicating that such resistance is widely spread in the Brazilian Amazon.
Assuntos
Cloroquina/farmacologia , Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Brasil , Cloroquina/uso terapêutico , Resistência Microbiana a Medicamentos , Feminino , Humanos , Malária/epidemiologia , Malária/parasitologia , MasculinoRESUMO
Oocysts of Eimeria crotalviridis sp. n. are described from praire rattlesnakes, Crotalus viridis viridis in New Mexico on the basis of light and electron microscopy and in vitro excystation of sporozoites. Sporulated oocysts of E. crotalviridis are elliptical, 26.4 X 22.3 (23-29 X 20-24) micrometer with ovoid sporocysts 11.7 X 8.1 (11-13 X 7-9) micromiter. A micropyle, micropyle cap and polar bodies are absent, but oocyst and sporocyst residua and Stieda and substieda bodies are present. Excysted sporozoites are 12.4 X 2.8 (11-13 X 2-3) micromiter and have 1 large posterior refractile body and a nucleus with a prominent nucleolus. Ultrastructurally, the oocyst wall has 2 layers, a thick, electron-dense, highly sculptured outer layer composed of a fine granular matrix and a thin, granular, osmiophilic inner layer, separated from the outer layer by at least one unit membrane. These layers are 441 (353-510) and 21.6 (19-29) nm thick, respectively. Within 15 min after exposure to a trypsin-sodium taurocholate fluid, sporozoites of E. crotalviridis excysted from 5-month-old sporocysts.