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Experimental infection parameters in Galea spixii (Rodentia: Caviidae) with Leishmania infantum chagasi
Barbosa, Patrícia Batista Barra Medeiros;Queiroz, Paula Viviane Sousa de;Jer?nimo, Selma Maria B;Ximenes, Maria de Fátima Freire de Melo;
Memórias do Instituto Oswaldo Cruz , 2008, DOI: 10.1590/S0074-02762008000600006
Abstract: in order to better understand the epidemiological transmission network of leishmaniasis, an endemic disease in northeast brazil, we investigated the susceptibility of spix yellow-toothed cavies (galea spixii) to the leishmania infantum chagasi parasite. nine cavies were experimentally infected, separated into three groups and monitored at 30, 90 and 180 days, respectively. amastigotes were identified in the spleen slides of two cavies killed 180 days after infection. antibodies against the l. i. chagasi were identified in one of the cavies. this demonstrates that g. spixii is in fact capable of maintaining a stable infection by l. i. chagasi without alterations in biochemical and hematological parameters of the host and without perceivable micro and macroscopic lesions.
Reproduction of Leishmania (Leishmania ) infantum chagasi in conditioned cell culture growth medium
Nogueira, Yeda L.;Galati, Eunice A.B.;
Revista do Instituto de Medicina Tropical de S?o Paulo , 2006, DOI: 10.1590/S0036-46652006000300006
Abstract: leishmanias can be produced by inoculation in conditioned mccoy cell culture growth medium (cgm). leishmania (leishmania) infantum chagasi (100 parasites) grown in nnn medium was inoculated in 2.5 ml cgm, kept in plates (24 wells) and its multiplication was observed for five days (120 hours). after day 5, the medium was saturated with the flagellate forms of the parasite (promastigotes). the reproduction of the leishmanias was observed every 24 hours and the number of parasites was calculated by counting the parasites in a drop of 10 μ l and photomicrographied. so the number of leishmanias was adjusted to 1 ml volume. the advantage of the technique by isolation of leishmania in cgm demonstrated in this study is its low cost and high efficacy even with a small quantity of parasites (102 promastigotes) used as inoculum. additionally, isolation of the leishmania can be obtained together with an increase in their density (180 times) as observed by growth kinetics, within a shorter time. these results justify the use of this low-cost technique for the isolation and investigation of the behavior and multiplication of leishmania both in vertebrates and invertebrates, besides offering means of obtaining antigens, whether whole antigens (leishmanias) or the soluble antigens produced by the parasites which may be useful for the production of new diagnostic kits.
The transmission of Leishmania infantum chagasi by the bite of the Lutzomyia longipalpis to two different vertebrates
Nagila FC Secundino, Vanessa C de Freitas, Carolina C Monteiro, Ana-Clara AM Pires, Bruna A David, Paulo FP Pimenta
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-20
Abstract: This study presents the establishment of a transmission model of Leishmania infantum chagasi by the bite of Lutzomyia longipalpis, the vector of American visceral leishmaniasis. The parasites were successfully transmitted by infected sandfly bites to mice and hamsters, indicating that both animals are good experimental models. The L. infantum chagasi dose that was transmitted in each single bite ranged from 10 to 10, 000 parasites, but 75% of the sandflies transmitted less than 300 parasites.The strategy for initiating infection by sandfly bite of experimental animals facilitates future investigations into the complex and dynamic mechanisms of visceral leishmaniasis. It is important to elucidate the transmission mechanism of vector bites. This model represents a useful tool to study L. infantum chagasi infection transmitted by the vector.Despite the fact that Leishmania is transmitted exclusively by sandfly vectors, a reproducible animal model of Leishmania infection transmitted by sandfly bite was only described in the year 2000 [1].Early investigations showed that infected P. papatasi sandflies can release from 0 to over 1,000 L. major promastigotes through their proboscides by forced feeding [2]. However, a transmission model by bite with P. duboscqui infected with L. major found that the parasite numbers inoculated in the host skin by one insect vector alone could vary from 10 to 100,000 [3].Considering the New World species of Leishmania, using a feeding device of chick skin membrane over culture medium showed that L. longipalpis sandflies infected with Leishmania mexicana (an unnatural vector/parasite pair) expelled an average of 1,000 parasites per fly [4]. Thus, even though L. longipalpis is the vector of L. infantum chagasi in nature, it is permissive in the laboratory to infection with other Leishmania species.In consideration of the continuing prevalence of American visceral leishmaniasis and the paucity of related studies in the literature, our goal was
Leishmania (Leishmania) infantum chagasi em canídeos silvestres mantidos em cativeiro, no Estado de Mato Grosso
Souza, Nely Pinheiro;Almeida, Arleana do Bom Parto Ferreira de;Freitas, Tatiana Pádua Tavares de;Paz, Regina Celia Rodrigues da;Dutra, Valéria;Nakazato, Luciano;Sousa, Valéria Régia Franco;
Revista da Sociedade Brasileira de Medicina Tropical , 2010, DOI: 10.1590/S0037-86822010000300024
Abstract: introduction: visceral leishmaniasis is a zoonosis that affects many mammals, and domestic canids are the main reservoirs in urban environments. this note describes infection by leishmania (leishmania) infantum chagasi among wild canids kept in captivity in the state of mato grosso, brazil. methods: skin, bone marrow and lymph node samples were collected from six crab-eating foxes (cerdocyon thous) and one bush dog (spheotos venaticus), in order to detect and characterize leishmania using the pcr-rflp technique. results: all the animals studied were positive for leishmania (l.) infantum chagasi. conclusions: this study highlights the importance of adequate monitoring of these animals, as well as greater control of this disease, given that these animals are in a public recreation environment.
Complete conservation of an immunogenic gene (lcr1) in Leishmania infantum and Leishmania chagasi isolated from Iran, Spain and Brazi  [PDF]
H. Mahmoudzadeh-Niknam , F. Abrishami , M. Doroudian , M. Moradi , M.H. Alimohammadian , P. Parvizi
Journal of Vector Borne Diseases , 2010,
Abstract: Background & objectives: Kala-azar is the visceral and most severe form of leishmaniasis thatleads to death if untreated. The causative agents of visceral leishmaniasis (VL) are members ofLeishmania (L.) donovani complex which includes L. chagasi and L. infantum. Genome sequenceshave raised the question whether L. chagasi and L. infantum are synonymous or different. Thisquestion has important implications for clinical and epidemiological studies, evaluation of vaccinesand drugs, and disease control. LCR1 is an immunogenic molecule discovered from L. chagasiwith potential as a component of a Leishmania subunit vaccine. If this protein has potentials forbeing used in a vaccine or diagnostic testing, there should be little variability in this moleculebetween L. infantum isolates from diverse geographic regions. The aim of this study was to determinewhether lcr1 of an Iranian strain of L. infantum was identical to lcr1 of both L. infantum strainfrom a different geographic region (Spain) and that of an L. chagasi isolate from Brazil.Methods: L. infantum isolated from an Iranian kala-azar patient was studied. Lcr1 from this isolatewas PCR amplified, cloned, and studied by restriction digest analysis and sequencing.Results: The sequences of lcr1 of the Iranian L. infantum were completely identical at nucleotidelevel to lcr1 sequences of both the Spanish L. infantum and the Brazilian L. chagasi strains.Conclusion: Complete conservation of the DNA sequence encoding for LCR1 molecule betweengeographically distinct Leishmania species adds credibility to the potential for LCR1 as a componentof a subunit vaccine and diagnostic test for kala-azar.
A novel A2 allele found in Leishmania (Leishmania) infantum chagasi
Oliveira, Trícia Maria Ferreira de Sousa;Vasconcelos, Elton José Rosas de;Nakaghi, Andréa Cristina Higa;Defina, Tania Paula Aquino;Jusi, Márcia Mariza Gomes;Baldani, Cristiane Divan;Cruz, ?ngela Kaysel;Machado, Rosangela Zacarias;
Revista Brasileira de Parasitologia Veterinária , 2011, DOI: 10.1590/S1984-29612011000100009
Abstract: visceral leishmaniasis (vl) is a widely spread zoonotic disease. in brazil the disease is caused by leishmania (leishmania) infantum chagasi. peridomestic sandflies acquire the etiological agent by feeding on blood of infected reservoir animals, such as dogs or wildlife. the disease is endemic in brazil and epidemic foci have been reported in densely populated cities all over the country. many clinical features of leishmania infection are related to the host-parasite relationship, and many candidate virulence factors in parasites that cause vl have been studied such as a2 genes. the a2 gene was first isolated in 1994 and then in 2005 three new alleles were described in leishmania (leishmania) infantum. in the present study we amplified by polymerase chain reaction (pcr) and sequenced the a2 gene from the genome of a clonal population of l. (l.) infantum chagasi vl parasites. the l. (l.) infantum chagasi a2 gene was amplified, cloned, and sequenced in. the amplified fragment showed approximately 90% similarity with another a2 allele amplified in leishmania (leishmania) donovani and in l.(l.) infantum described in literature. however, nucleotide translation shows differences in protein amino acid sequence, which may be essential to determine the variability of a2 genes in the species of the l. (l.) donovani complex and represents an additional tool to help understanding the role this gene family may have in establishing virulence and immunity in visceral leishmaniasis. this knowledge is important for the development of more accurate diagnostic tests and effective tools for disease control.
Factores de riesgo involucrados en la infección por Leishmania infantum / L. chagasi
Rosilved,R; Silva,B;
Revista del Instituto Nacional de Higiene Rafael Rangel , 2008,
Abstract: visceral leishmaniasis (v.l.) or kala-azar is a disease caused by parasite complex leishmania donovani, its extense geographical distribution and their incidence around the world is near 500.000 new cases per year. leishmania infantum / l. chagasi is the causal agent in south america, this disease is potentially lethal when not early and properly treated causal agent. in venezuela, nueva esparta state show the highest annual incidence of this disease. there are many risk factors that was responsible for the increase of leishmania infantum/ l.chagasi infection. this article is a review of current epidemiological observations.
Factores de riesgo involucrados en la infección por Leishmania infantum / L. chagasi Risk factors involved in Leishmania infantum / L. chagasi Infection
R Rosilved,B Silva
Revista del Instituto Nacional de Higiene Rafael Rangel , 2008,
Abstract: La Leishmaniasis visceral (L.V.) o kala-azar es una enfermedad causada por parásitos que pertenecen al complejo Leishmania donovani, cuya especie en Suramérica es la Leishmania infantum / L. chagasi. Es una enfermedad con alto potencial letal si el tratamiento no es iniciado en forma oportuna. La L.V. es de amplia distribución geográfica y la incidencia mundial es de 500.000 casos nuevos al a o, siendo el estado Nueva Esparta el que presenta la mayor tasa de incidencia anual en nuestro país. Son muchos los factores que se han descrito, influyen en la aparición de la infección de Leishmania infantum / L. chagasi y en este artículo se presenta una revisión de los mismos. Visceral Leishmaniasis (V.L.) or kala-azar is a disease caused by parasite complex Leishmania donovani, its extense geographical distribution and their incidence around the world is near 500.000 new cases per year. Leishmania infantum / L. chagasi is the causal agent in South America, this disease is potentially lethal when not early and properly treated causal agent. In Venezuela, Nueva Esparta State show the highest annual incidence of this disease. There are many risk factors that was responsible for the increase of Leishmania infantum/ L.chagasi infection. This article is a review of current epidemiological observations.
Application of Serial Analysis of Gene Expression to the Study of the Gene Expression Profile of Leishmania infantum chagasi Promastigote
Adelino Soares Lima Neto,Osvaldo Pompílio de Melo Neto,Carlos Henrique Nery Costa
Journal of Biomedicine and Biotechnology , 2012, DOI: 10.1155/2012/673458
Abstract: This study describes the application of the LongSAGE methodology to study the gene expression profile in promastigotes of Leishmania infantum chagasi. A tag library was created using the LongSAGE method and consisted of 14,208 tags of 17 bases. Of these, 8,427 (59.3%) were distinct. BLAST research of the 1,645 most abundant tags showed that 12.8% of them identified the coding sequences of genes, while 82% (1,349/1,645) identified one or more genomic sequences that did not correspond with open reading frames. Only 5.2% (84/1,645) of the tags were not aligned to any position in the L. infantum genome. The UTR size of Leishmania and the lack of CATG sites in some transcripts were decisive for the generation of tags in these regions. Additional analysis will allow a better understanding of the expression profile and discovering the key genes in this life cycle.
Vaccination with L. infantum chagasi Nucleosomal Histones Confers Protection against New World Cutaneous Leishmaniasis Caused by Leishmania braziliensis  [PDF]
Marcia W. Carneiro, Diego M. Santos, Kiyoshi F. Fukutani, Jorge Clarencio, Jose Carlos Miranda, Claudia Brodskyn, Aldina Barral, Manoel Barral-Netto, Manuel Soto, Camila I. de Oliveira
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0052296
Abstract: Background Nucleosomal histones are intracellular proteins that are highly conserved among Leishmania species. After parasite destruction or spontaneous lysis, exposure to these proteins elicits a strong host immune response. In the present study, we analyzed the protective capability of Leishmania infantum chagasi nucleosomal histones against L. braziliensis infection using different immunization strategies. Methodology/Principal Findings BALB/c mice were immunized with either a plasmid DNA cocktail (DNA) containing four Leishmania nucleosomal histones or with the DNA cocktail followed by the corresponding recombinant proteins plus CpG (DNA/Protein). Mice were later challenged with L. braziliensis, in the presence of sand fly saliva. Lesion development, parasite load and the cellular immune response were analyzed five weeks after challenge. Immunization with either DNA alone or with DNA/Protein was able to inhibit lesion development. This finding was highlighted by the absence of infected macrophages in tissue sections. Further, parasite load at the infection site and in the draining lymph nodes was also significantly lower in vaccinated animals. This outcome was associated with increased expression of IFN-γ and down regulation of IL-4 at the infection site. Conclusion The data presented here demonstrate the potential use of L. infantum chagasi nucleosomal histones as targets for the development of vaccines against infection with L. braziliensis, as shown by the significant inhibition of disease development following a live challenge.
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