3,720 research outputs found

    Molecular epidemiology of domestic and sylvatic Trypanosoma cruzi infection in rural northwestern Argentina

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    Genetic diversity of Trypanosoma cruzi populations and parasite transmission dynamics have been well documented throughout the Americas, but few studies have been conducted in the Gran Chaco ecoregion, one of the most highly endemic areas for Chagas disease, caused by T. cruzi. In this study, we assessed the distribution of T. cruzi lineages (identified by PCR strategies) in Triatoma infestans, domestic dogs, cats, humans and sylvatic mammals from two neighbouring rural areas with different histories of transmission and vector control in northern Argentina. Lineage II predominated amongst the 99 isolates characterised and lineage I amongst the six isolates obtained from sylvatic mammals. T. cruzi lineage IIe predominated in domestic habitats; it was found in 87% of 54 isolates from Tr. infestans, in 82% of 33 isolates from dogs, and in the four cats found infected. Domestic and sylvatic cycles overlapped in the study area in the late 1980s, when intense domestic transmission occurred, and still overlap marginally. The introduction of T. cruzi from sylvatic into domestic habitats is likely to occur very rarely in the current epidemiological context. The household distribution of T. cruzi lineages showed that Tr. infestans, dogs and cats from a given house compound shared the same parasite lineage in most cases. Based on molecular evidence, this result lends further support to the importance of dogs and cats as domestic reservoir hosts of T. cruzi. We believe that in Argentina, this is the first time that lineage IIc has been isolated from naturally infected domestic dogs and Tr. infestans.Fil: Cardinal, Marta Victoria. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Lauricella, Marta A.. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud “Dr. C.G. Malbrán”. Instituto Nacional de Parasitología “Dr. M. Fatala Chabén”; ArgentinaFil: Ceballos, Leonardo A.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Lanati, Leonardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Marcet, Paula Lorena. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Levin, Mariano Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Kitron, Uriel D.. Emory University; Estados UnidosFil: Gurtler, Ricardo Esteban. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentin

    Novel parvoviruses from wild and domestic animals in Brazil provide new insights into parvovirus distribution and diversity

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    Parvoviruses (family Parvoviridae) are small, single-stranded DNA viruses. Many parvoviral pathogens of medical, veterinary and ecological importance have been identified. In this study, we used high-throughput sequencing (HTS) to investigate the diversity of parvoviruses infecting wild and domestic animals in Brazil. We identified 21 parvovirus sequences (including twelve nearly complete genomes and nine partial genomes) in samples derived from rodents, bats, opossums, birds and cattle in Pernambuco, São Paulo, Paraná and Rio Grande do Sul states. These sequences were investigated using phylogenetic and distance-based approaches and were thereby classified into eight parvovirus species (six of which have not been described previously), representing six distinct genera in the subfamily Parvovirinae. Our findings extend the known biogeographic range of previously characterized parvovirus species and the known host range of three parvovirus genera (Dependovirus, Aveparvovirus and Tetraparvovirus). Moreover, our investigation provides a window into the ecological dynamics of parvovirus infections in vertebrates, revealing that many parvovirus genera contain well-defined sub-lineages that circulate widely throughout the world within particular taxonomic groups of hosts

    On the development of the chondrocranium and the histological anatomy of the head in perinatal stages of marsupial mammals

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    An overview of the literature on the chondrocranium of marsupial mammals reveals a relative conservatism in shape and structures. We document the histological cranial anatomy of individuals representing Monodelphis domestica, Dromiciops gliroides, Perameles sp. and Macropus eugenii. The marsupial chondrocranium is generally characterized by the great breadth of the lamina basalis, absence of pila metoptica and large otic capsules. Its most anterior portion (cupula nasi anterior) is robust, and anterior to it there are well-developed tactile sensory structures, functionally important in the neonate. Investigations of ossification centers at and around the nasal septum are needed to trace the presence of certain bones (e.g., mesethmoid, parasphenoid) across marsupial taxa. In many adult marsupials, the tympanic floor is formed by at least three bones: alisphenoid (alisphenoid tympanic process), ectotympanic and petrosal (rostral and caudal tympanic processes); the squamosal also contributes in some diprotodontians. The presence of an entotympanic in marsupials has not been convincingly demonstrated. The tubal element surrounding the auditory tube in most marsupials is fibrous connective tissue rather than cartilage; the latter is the case in most placentals recorded to date. However, we detected fibrocartilage in a late juvenile of Dromiciops, and a similar tissue has been reported for Tarsipes. Contradictory reports on the presence of the tegmen tympani can be found in the literature. We describe a small tegmen tympani in Macropus. Several heterochronic shifts in the timing of development of the chondocranium and associated structures (e.g., nerves, muscles) and in the ossification sequence have been interpreted as largely being influenced by functional requirements related to the altriciality of the newborn marsupial during early postnatal life. Comparative studies of chondocranial development of mammals can benefit from a solid phylogenetic framework, research on non-classical model organisms, and integration with imaging and sectional data derived from computer-tomography.Fil: Sánchez Villagra, Marcelo R.. Universitat Zurich; SuizaFil: Forasiepi, Analia Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

    First report of Trichinella spiralis from the white-eared (Didelphis albiventris) and the thick-tailed opossum (Lutreolina crassicaudata) in central Argentina

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    Trichinellosis is a zoonotic disease caused by nematodes of the genus Trichinella. Humans, who are the final hosts, acquire the infection by eating raw or undercooked meat of different animal origin. Trichinella spiralis is an encapsulated species that infects mammals and is widely distributed in different continents. In Argentina, this parasite has been reported in the domestic cycle that includes pigs and synanthropic hosts (mainly rats and some carnivores). This is the first report of T. spiralis in the opossums Didelphis albiventris and Lutreolina crassicaudata in Argentina, and the first report in opossums in South America. In this survey, Trichinella larvae were detected by enzymatic digestion in three D. albiventris and one L. crassicaudata captured on pig and dairy farms located in the northeast of Buenos Aires province. The microscopic examination of the 32 larvae isolated presented the diagnostic characteristic of the genus Trichinella. Two larvae isolated from two D. albiventris and one from L. crassicaudata were identified as T. spiralis by nested multiplex PCR and confirmed by sequencing. Further research to determine the burdens of T. spiralis in opossums may contribute to a better understanding of the risk of T. spiralis transmission to the synanthropic populations.Fil: Castaño Zubieta, R.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Ruiz, M.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Morici, G.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Lovera, Rosario. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Caracostantogolo, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Cavia, Regino. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Prevalence of Sarcocystis calchasi in free-ranging host species: Accipiter hawks and Common Woodpigeon in Germany

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    The apicomplexan parasite Sarcocystis calchasi (S. calchasi) triggers pigeon protozoal encephalitis, a neurologic disease in columbids. Accipiter hawks have been identified as the final host, and Columbidae and Psittaciformes as intermediate hosts. In this study, 368 free-ranging Accipiter hawks and 647 free-ranging common woodpigeons were sampled in a country-wide study in order to identify the prevalence of S. calchasi in these populations. A semi-nested PCR specific for S. calchasi tested positive in 7.3% (4.9-10.5) of submitted samples from Accipiter hawks. Juvenile Accipiter hawks (13.7%; 7.7-22.0) had a significantly higher infection rate with S. calchasi than adult Accipiter hawks (5.8%; 2.7-9.3). The prevalence of S. calchasi in common woodpigeons was 3.3% (5.4-9.7). Positive pigeons were identified in 14/16 federal states, and a region-dependency was detected, with higher rates of infection in the eastern parts of Germany. The results of this study suggest that the common woodpigeon is a natural reservoir for S. calchasi. In a study of one region for four consecutive years, an increase in prevalence was not detected. Findings indicate that the parasite is not newly introduced to Germany, but rather long established. The prevalence suggests that there is a substantial risk of S. calchasi infections in other free-ranging as well as captive host species

    Thalidomide-induced teratogenesis in gray short-tailed opossums (Monodelphis domestica)

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    From 1957 to 1962, Thalidomide was prescribed to pregnant women as an antiemetic and was later discovered to cause serious birth defects. Thalidomide is currently being prescribed to treat erythema nodosum leprosum and multiple melanoma, and is being considered for other anti-angiogenic applications. This is of concern, as the mechanisms by which thalidomide disrupts development remain largely unknown. This lack of knowledge is largely due to the absence of an appropriate model mammalian system. Traditional mammal models, such as rats and mice, are resistant to the teratogenic properties of thalidomide. We propose to develop the gray short-tailed opossum (Monodelphis domestica) as a novel mammalian to study thalidomide teratogenesis. In M. domestica we have successfully recreated most morphological defects found in human thalidomide victims. Through RNA sequencing, we have also identified two gene that may play a significant role in the mechanism of thalidomide induced birth defects

    Longevity Genes: From Primitive Organisms to Humans

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    A variety of lines of evidence indicate that aging and longevity are subject to genetic regulation, but until fairly recently the identity of these genes was unknown. This has changed dramatically over the last ten years. Recommends several courses of carrying research on "longevity genes" to humans

    Solving wildlife damage problems in Missouri (2011)

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    Wildlife are valuable natural resources and important components of a healthy ecosystem. They also provide many economic, recreational and aesthetic benefits. However, given the wrong set of circumstances, almost any species of wildlife can become a nuisance. This guide provides basic information on how to prevent and solve wildlife damage problems and includes a list of technical and educational resources
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