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Search Results: 1 - 10 of 3468 matches for " Elisa Cupolillo "
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Speculations on the origin and evolution of the genus Leishmania
Momen, Hooman;Cupolillo, Elisa;
Memórias do Instituto Oswaldo Cruz , 2000, DOI: 10.1590/S0074-02762000000400023
Abstract: recently two hypotheses have been proposed for the evolution of leishmania involving respectively a neotropical or paleartic origin for the species. here an alternative proposal on the phylogeny of leishmania based on the major divisions within the genus is presented. in this hypothesis a neotropic origin is retained for l. (viannia) and paraleishmania, a recently desribed section within the genus leishmania, while an african origin is proposed for l. (leishmania) and possibly sauroleishmania. the current distribution of leishmania in the neotropics is explained as the product of multiple introductions of leishmania parasites into the new world. problems with organismal identity in sauroleishmania and the use of molecular sequence data in inferring phylogenies are also discussed.
Speculations on the origin and evolution of the genus Leishmania
Momen Hooman,Cupolillo Elisa
Memórias do Instituto Oswaldo Cruz , 2000,
Abstract: Recently two hypotheses have been proposed for the evolution of Leishmania involving respectively a Neotropical or Paleartic origin for the species. Here an alternative proposal on the phylogeny of Leishmania based on the major divisions within the genus is presented. In this hypothesis a Neotropic origin is retained for L. (Viannia) and Paraleishmania, a recently desribed section within the genus Leishmania, while an African origin is proposed for L. (Leishmania) and possibly Sauroleishmania. The current distribution of Leishmania in the Neotropics is explained as the product of multiple introductions of Leishmania parasites into the New World. Problems with organismal identity in Sauroleishmania and the use of molecular sequence data in inferring phylogenies are also discussed.
Genetic Diversity in Natural Populations of New World Leishmania
Cupolillo, Elisa;Momen, Hooman;Grimaldi Jr, Gabriel;
Memórias do Instituto Oswaldo Cruz , 1998, DOI: 10.1590/S0074-02761998000500018
Abstract: our results have shown the wide diversity of parasites within new world leishmania. biochemical and molecular characterization of species within the genus has revealed that much of the population heterogeneity has a genetic basis. the source of genetic diversity among leishmania appears to arise from predominantly asexual, clonal reproduction, although occasional bouts of sexual reproduction can not be ruled out. genetic variation is extensive with some clones widely distributed and others seemingly unique and localized to a particular endemic focus. epidemiological studies of leishmaniasis has been directed to the ecology and dynamics of transmission of leishmania species/variants, particularly in localized areas. future research using molecular techniques should aim to identify and follow leishmania types in nature and correlate genetic typing with important clinical characteristics such as virulence, pathogenicity, drug resistance and antigenic variation. the epidemiological significance of such variation not only has important implications for the control of the leishmaniases, but would also help to elucidate the evolutionary biology of the causative agents.
Genetic Diversity in Natural Populations of New World Leishmania
Cupolillo Elisa,Momen Hooman,Grimaldi Jr Gabriel
Memórias do Instituto Oswaldo Cruz , 1998,
Abstract: Our results have shown the wide diversity of parasites within New World Leishmania. Biochemical and molecular characterization of species within the genus has revealed that much of the population heterogeneity has a genetic basis. The source of genetic diversity among Leishmania appears to arise from predominantly asexual, clonal reproduction, although occasional bouts of sexual reproduction can not be ruled out. Genetic variation is extensive with some clones widely distributed and others seemingly unique and localized to a particular endemic focus. Epidemiological studies of leishmaniasis has been directed to the ecology and dynamics of transmission of Leishmania species/variants, particularly in localized areas. Future research using molecular techniques should aim to identify and follow Leishmania types in nature and correlate genetic typing with important clinical characteristics such as virulence, pathogenicity, drug resistance and antigenic variation. The epidemiological significance of such variation not only has important implications for the control of the leishmaniases, but would also help to elucidate the evolutionary biology of the causative agents.
Genetic diversity of Colombian sylvatic Trypanosoma cruzi isolates revealed by the ribosomal DNA
Cuervo, Patricia;Cupolillo, Elisa;Segura, Iris;Saravia, Nancy;Fernandes, Octavio;
Memórias do Instituto Oswaldo Cruz , 2002, DOI: 10.1590/S0074-02762002000600023
Abstract: american trypanosomiasis is a common zoonosis in colombia and trypanosoma cruzi presents a wide distribution throughout the country. although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using colombian strains. in this study, we amplified the non-transcribed spacer of the mini-gene by pcr, typing the isolates as t. cruzi i, t. cruzi zymodeme 3 or t. rangeli. in addition, the internal transcribed spacers of the ribosomal gene concomitant with the 5.8s rdna were amplified and submitted to restriction fragment polymorphism analysis. the profiles were analyzed by a numerical methodology generating a phenetic dendrogram that shows heterogeneity among the t. cruzi isolates. this finding suggests a relationship between the complexity of the sylvatic transmission cycle in colombia and the diversity of the sylvan parasites.
Genetic diversity of Colombian sylvatic Trypanosoma cruzi isolates revealed by the ribosomal DNA
Cuervo Patricia,Cupolillo Elisa,Segura Iris,Saravia Nancy
Memórias do Instituto Oswaldo Cruz , 2002,
Abstract: American trypanosomiasis is a common zoonosis in Colombia and Trypanosoma cruzi presents a wide distribution throughout the country. Although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using Colombian strains. In this study, we amplified the non-transcribed spacer of the mini-gene by PCR, typing the isolates as T. cruzi I, T. cruzi zymodeme 3 or T. rangeli. In addition, the internal transcribed spacers of the ribosomal gene concomitant with the 5.8S rDNA were amplified and submitted to restriction fragment polymorphism analysis. The profiles were analyzed by a numerical methodology generating a phenetic dendrogram that shows heterogeneity among the T. cruzi isolates. This finding suggests a relationship between the complexity of the sylvatic transmission cycle in Colombia and the diversity of the sylvan parasites.
Cutaneous Leishmaniasis in Venezuela Caused by Infection with a New Hybrid between Leishmania (Viannia) braziliensis and L. (V.) guyanensis
Delgado Olinda,Cupolillo Elisa,Bonfante-Garrido Rafael,Silva Silvia
Memórias do Instituto Oswaldo Cruz , 1997,
Abstract:
Genetic Data Showing Evolutionary Links between Leishmania and Endotrypanum
Cupolillo Elisa,Pereira Luiza OR,Fernandes Octávio,Catanho Marcos P
Memórias do Instituto Oswaldo Cruz , 1998,
Abstract: Striking similarities at the morphological, molecular and biological levels exist between many trypanosomatids isolated from sylvatic insects and/or vertebrate reservoir hosts that make the identification of medically important parasites demanding. Some molecular data have pointed to the relationship between some Leishmania species and Endotrypanum, which has an important epidemiological significance and can be helpful to understand the evolution of those parasites. In this study, we have demonstrated a close genetic relationship between Endotrypanum and two new leishmanial species, L. (V.) colombiensis and L. (V.) equatorensis. We have used (a) numerical zymotaxonomy and (b) the variability of the internal transcribed spacers of the rRNA genes to examine relationships in this group. The evolutionary trees obtained revealed high genetic similarity between L. (V.) colombiensis, L. (V.) equatorensis and Endotrypanum, forming a tight cluster of parasites. Based on further results of (c) minicircle kDNA heterogeneity analysis and (d) measurement of the sialidase activity these parasites were also grouped together.
New Insights on Taxonomy, Phylogeny and Population Genetics of Leishmania (Viannia) Parasites Based on Multilocus Sequence Analysis
Mariana C. Boité,Isabel L. Mauricio,Michael A. Miles,Elisa Cupolillo
PLOS Neglected Tropical Diseases , 2012, DOI: 10.1371/journal.pntd.0001888
Abstract: The Leishmania genus comprises up to 35 species, some with status still under discussion. The multilocus sequence typing (MLST)—extensively used for bacteria—has been proposed for pathogenic trypanosomatids. For Leishmania, however, a detailed analysis and revision on the taxonomy is still required. We have partially sequenced four housekeeping genes—glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), mannose phosphate isomerase (MPI) and isocitrate dehydrogenase (ICD)—from 96 Leishmania (Viannia) strains and assessed their discriminatory typing capacity. The fragments had different degrees of diversity, and are thus suitable to be used in combination for intra- and inter-specific inferences. Species-specific single nucleotide polymorphisms were detected, but not for all species; ambiguous sites indicating heterozygosis were observed, as well as the putative homozygous donor. A large number of haplotypes were detected for each marker; for 6PGD a possible ancestral allele for L. (Viannia) was found. Maximum parsimony-based haplotype networks were built. Strains of different species, as identified by multilocus enzyme electrophoresis (MLEE), formed separated clusters in each network, with exceptions. NeighborNet of concatenated sequences confirmed species-specific clusters, suggesting recombination occurring in L. braziliensis and L. guyanensis. Phylogenetic analysis indicates L. lainsoni and L. naiffi as the most divergent species and does not support L. shawi as a distinct species, placing it in the L. guyanensis cluster. BURST analysis resulted in six clonal complexes (CC), corresponding to distinct species. The L. braziliensis strains evaluated correspond to one widely geographically distributed CC and another restricted to one endemic area. This study demonstrates the value of systematic multilocus sequence analysis (MLSA) for determining intra- and inter-species relationships and presents an approach to validate the species status of some entities. Furthermore, it contributes to the phylogeny of L. (Viannia) and might be helpful for epidemiological and population genetics analysis based on haplotype/diplotype determinations and inferences.
Thrichomys laurentius (Rodentia; Echimyidae) as a Putative Reservoir of Leishmania infantum and L. braziliensis: Patterns of Experimental Infection
André Luiz Rodrigues Roque,Elisa Cupolillo,Renato Sergio Marchevsky,Ana Maria Jansen
PLOS Neglected Tropical Diseases , 2010, DOI: 10.1371/journal.pntd.0000589
Abstract: The importance of the genus Thrichomys in the retention of infection and transmission of Leishmania species is supported by previous studies that describe an ancient interaction between caviomorphs and trypanosomatids and report the natural infection of Thrichomys spp. Moreover, these rodents are widely dispersed in Brazil and recognized as important hosts of other tripanosomatids. Our main purpose was to evaluate the putative role of Thrichomys laurentius in the retention of infection and amplification of the transmission cycle of Leishmania infantum and L. braziliensis. Male and female T. laurentius (n = 24) born in captivity were evaluated for the retention of infection with these Leishmania species and followed up by parasitological, serological, hematological, biochemical, histological, and molecular assays for 3, 6, 9, or 12 months post infection (mpi). T. laurentius showed its competence as maintenance host for the two inoculated Leishmania species. Four aspects should be highlighted: (i) re-isolation of parasites 12 mpi; (ii) the low parasitic burden displayed by T. laurentius tissues; (iii) the early onset and maintenance of humoral response, and (iv) the similar pattern of infection by the two Leishmania species. Both Leishmania species demonstrated the ability to invade and maintain itself in viscera and skin of T. laurentius, and no rodent displayed any lesion, histological changes, or clinical evidence of infection. We also wish to point out the irrelevance of the adjective dermotropic or viscerotropic to qualify L. braziliensis and L. infantum, respectively, when these species are hosted by nonhuman hosts. Our data suggest that T. laurentius may act at least as a maintenance host of both tested Leishmania species since it maintained long-lasting infections. Moreover, it cannot be discarded that Leishmania spp. infection in free-ranging T. laurentius could result in higher parasite burden due the more stressing conditions in the wild. Therefore the tissular parasitism of the skin, infectiveness to the vector, and amplification of the transmission cycle of both Leishmania species could be expected.
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