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Tania M S Silva - One of the best experts on this subject based on the ideXlab platform.
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improved synthesis of seven aromatic baylis hillman adducts bha evaluation against artemia salina leach and Leishmania chagasi
European Journal of Medicinal Chemistry, 2009Co-Authors: Ticiano P Barbosa, Claudio G L, Fabio P L Silva, Horacimone M Lopes, Lucas Ricardo Fernandes Figueiredo, Suervy C O Sousa, Guilherme N Batista, Thiago G Da Silva, Tania M S SilvaAbstract:We described a very efficient procedure to prepare seven aromatic compounds (1-7), a new class of antiLeishmanial substances, through Baylis-Hillman reaction (BHR). With one, all the Baylis-Hillman adducts were prepared in quantitative yields by reaction of the corresponding aromatic aldehydes in acrylonitrile at 0 degrees C in only 10-40min reaction time. We present our results about the toxicities of these compounds evaluated on the microcrustaceous Artemia salina Leach. and against promastigote Leishmania chagasi. All substances evaluated in this work have showed high bioactivity. The 3-hydroxy-2-methylene-3-(4-bromopheny)propanenitrile (4) (LC(50)=30.9 microg/mL on A. salina; IC(50)=25.2 microM on L. chagasi) was the most active compound evaluated on A. salina Leach. and on promastigote L. chagasi. The 2-[hydroxy(pyridin-4-yl)methyl]acrylonitrile (7) (LC(50)=30.9 microg/mL on A. salina Leach.; IC(50)=4.8 microg/mL on L. chagasi) was also a very active substance evaluated in this work on promastigote L. chagasi.
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improved synthesis of seven aromatic baylis hillman adducts bha evaluation against artemia salina leach and Leishmania chagasi
European Journal of Medicinal Chemistry, 2009Co-Authors: Ticiano P Barbosa, Claudio G L, Fabio P L Silva, Horacimone M Lopes, Lucas Ricardo Fernandes Figueiredo, Suervy C O Sousa, Guilherme N Batista, Thiago G Da Silva, Tania M S SilvaAbstract:Abstract We described a very efficient procedure to prepare seven aromatic compounds ( 1 – 7 ), a new class of antiLeishmanial substances, through Baylis–Hillman reaction (BHR). With one, all the Baylis–Hillman adducts were prepared in quantitative yields by reaction of the corresponding aromatic aldehydes in acrylonitrile at 0 °C in only 10–40 min reaction time. We present our results about the toxicities of these compounds evaluated on the microcrustaceous Artemia salina Leach. and against promastigote Leishmania chagasi . All substances evaluated in this work have showed high bioactivity. The 3-hydroxy-2-methylene-3-(4-bromopheny)propanenitrile ( 4 ) (LC 50 = 30.9 μg/mL on A. salina ; IC 50 = 25.2 μM on L. chagasi ) was the most active compound evaluated on A. salina Leach. and on promastigote L. chagasi . The 2-[hydroxy(pyridin-4-yl)methyl]acrylonitrile ( 7 ) (LC 50 = 30.9 μg/mL on A. salina Leach.; IC 50 = 4.8 μg/mL on L. chagasi ) was also a very active substance evaluated in this work on promastigote L. chagasi .
Ana Rabello - One of the best experts on this subject based on the ideXlab platform.
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AntiLeishmanial Activity of Azithromycin Against Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) chagasi
2015Co-Authors: A De Oliveira-silva, Eliane De Morais-teixeira, Ana RabelloAbstract:Abstract. Azithromycin, an azalide antibiotic, is highly concentrated within different phagocytic cells, especially macrophages. The potential antiLeishmanial activity of azithromycin against three species of Leishmania from the New World was assessed using in vitro models. Azithromycin decreased viability of promastigote cultures of Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) chagasi as determined by the colorimetric Alamar blue assay. In amastigote intracellular cultures, a significant decrease in infected macrophages counts was observed for all three species with IC50 of 20.83 (27 mol/L), 2.18 (2.7 mol/L), and 6.12 (7.8 mol/L) g/mL, respectively. Azithromycin showed in vitro activity against L. (L.) amazonensis, L. (V.) braziliensis, and L. (L.) chagasi and may offer an alternative to current Leishmaniasis treatment
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AntiLeishmanial activity of azithromycin against Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) chagasi.
The American journal of tropical medicine and hygiene, 2008Co-Authors: Fernanda De Oliveira-silva, Eliane De Morais-teixeira, Ana RabelloAbstract:Azithromycin, an azalide antibiotic, is highly concentrated within different phagocytic cells, especially macrophages. The potential antiLeishmanial activity of azithromycin against three species of Leishmania from the New World was assessed using in vitro models. Azithromycin decreased viability of promastigote cultures of Leishmania (Leishmania) amazonensis, Leishmania (Viannia) braziliensis, and Leishmania (Leishmania) chagasi as determined by the colorimetric Alamar blue assay. In amastigote intracellular cultures, a significant decrease in infected macrophages counts was observed for all three species with IC50 of 20.83 (27 mol/L), 2.18 (2.7 mol/L), and 6.12 (7.8 mol/L) g/mL, respectively. Azithromycin showed in vitro activity against L.( L.) amazonensis, L.( V.) braziliensis, and L.( L.) chagasi and may offer an alternative to current Leishmaniasis treatment. Tegumentary and visceral Leishmaniasis are listed among World Health Organization tropical disease priorities because of their significant impact on global public health. Cutaneous Leishmaniasis in the Americas are mainly caused by Leishma- nia (Viannia) braziliensis, Leishmania (Leishmania) amazon- ensis, and Leishmania (Viannia) guyanensis and produces skin ulcers on exposed parts of the body such as the face, arms, and legs. The lesions vary from mild to severe and may cause serious disability, leaving the patient permanently scarred. Additionally, cutaneous disease caused by the Vian- nia subgenus may progress to mucosal involvement and in- fection caused by L. (L.) amazonensis, may result in diffuse cutaneous Leishmaniasis, a severe non-responsive form. Vis- ceral Leishmaniasis is a severe disease caused by parasites of the Leishmania donovani complex, characterized by long- term fever, hepatosplenomegaly, anemia, leucopenia, and se- vere weight loss, which is fatal if left untreated. The causative agent of the visceral form in the New World is L.( L.) chagasi. The classic treatment of different clinical forms of leishma- niasis is the pentavalent antimony in the form of either sti- bogluconate sodium (Pentostam) or meglumine antimoniate (Glucantime; Aventis Pharma Ltda, Suzano, SP-Brazil). 1 Pentavalent antimonials remain the first-line drugs against Leishmaniasis worldwide, notwithstanding many critical disad- vantages concerning parenteral administration, long-term therapy, and potentially severe side effects associated with dosage and toxicity. In the last decade, new therapeutic options have been in- troduced for the treatment of visceral and cutaneous leish- maniasis such as aminosidine (paromomycin) for both topical and parenteral administration, lipid-associated amphotericin B, oral miltefosine and sitamaquine. 2 Several other com- pounds have undergone limited evaluation, namely the azoles, itraconazole, ketaconazole, and fluconazole. 3-5 All an-
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mixed inflammatory regulatory cytokine profile marked by simultaneous raise of interferon gamma and interleukin 10 and low frequency of tumour necrosis factor alpha monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection
Clinical and Experimental Immunology, 2006Co-Authors: Vanessa Peruhypemagalhaes, Ana Rabello, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Aluizio Prata, L De A Silva, Rosely Moralez De Figueiredo, S F Guimaraescarvalho, Teresa Cristina Abreu FerrariAbstract:Summary Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particu- larly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infec- tion. Although asymptomatic individuals and non-infected subjects pre- sented a similar immunological profile, an outstanding inflammatory/ regulatory profile, based on higher plasmatic levels of cytokines such as inter- leukin (IL)-8, interferon (IFN)- γ , tumour necrosis factor (TNF)- α , IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-Leishmanial mac- rophage activation, associated with the lower frequency of TNF- α + monocytes
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mixed inflammatory regulatory cytokine profile marked by simultaneous raise of interferon gamma and interleukin 10 and low frequency of tumour necrosis factor alpha monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection
Clinical and Experimental Immunology, 2006Co-Authors: Vanessa Peruhypemagalhaes, Ana Rabello, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Aluizio Prata, L De A Silva, Rosely Moralez De Figueiredo, S F Guimaraescarvalho, Teresa Cristina Abreu FerrariAbstract:Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particularly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infection. Although asymptomatic individuals and non-infected subjects presented a similar immunological profile, an outstanding inflammatory/regulatory profile, based on higher plasmatic levels of cytokines such as interleukin (IL)-8, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-Leishmanial macrophage activation, associated with the lower frequency of TNF-alpha(+) monocytes and ordinary levels of nitrite and nitrate are the major mechanisms associated with disease onset.
Andrea Teixeiracarvalho - One of the best experts on this subject based on the ideXlab platform.
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influence of clinical status and parasite load on erythropoiesis and leucopoiesis in dogs naturally infected with Leishmania Leishmania chagasi
PLOS ONE, 2011Co-Authors: Raquel Tropia De Abreu, Rodolfo Cordeiro Giunchetti, Rodrigo Correaoliveira, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Maria Das Gracas Carvalho, Claudia Martins Carneiro, Wendel Couravital, Alexandre Barbosa ReisAbstract:Background: The bone marrow is considered to be an important storage of parasites in Leishmania-infected dogs, although little is known about cellular genesis in this organ during canine visceral Leishmaniasis (CVL). Methodology/Principal Findings: The aim of the present study was to evaluate changes in erythropoiesis and leucopoiesis in bone marrow aspirates from dogs naturally infected with Leishmania chagasi and presenting different clinical statuses and bone marrow parasite densities. The evolution of CVL from asymptomatic to symptomatic status was accompanied by increasing parasite density in the bone marrow. The impact of bone marrow parasite density on cellularity was similar in dogs at different clinical stages, with animals in the high parasite density group. Erythroid and eosinophilic hypoplasia, proliferation of neutrophilic precursor cells and significant increases in lymphocytes and plasma cell numbers were the major alterations observed. Differential bone marrow cell counts revealed increases in the myeloid:erythroid ratio associated to increased numbers of granulopoietic cells in the different clinical groups compared with non-infected dogs. Conclusions: Analysis of the data obtained indicated that the assessment of bone marrow constitutes an additional and useful tool by which to elaborate a prognosis for CVL.
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anti fixed Leishmania chagasi promastigotes igg antibodies detected by flow cytometry fc afpa igg as a tool for serodiagnosis and for post therapeutic cure assessment in american visceral Leishmaniasis
Journal of Immunological Methods, 2009Co-Authors: Lucia Maria Garcia, Andrea Teixeiracarvalho, Reynaldo Dietze, Vanessa Peruhypemagalhaes, Jordana Grazziela Coelhodosreis, Roberta Dias Rodrigues Rocha, Marcio Sobreira Silva Araujo, Izabelle Teixeira Gomes, Silvio Fernando Guimaraes Carvalho, Elenice Moreira LemosAbstract:Visceral Leishmaniasis (VL) is a systemic infection, caused by an intracellular protozoan parasite belonging to the Leishmania donovani complex. The diagnosis of VL is complex because most clinical features are shared with other commonly occurring febrile hepatosplenic diseases that can be endemic along with VL. A number of serological devices are available but still require improvement mainly due to residual post-therapeutic serology and the cross-reactivity with other Trypanosomatidae protozooses. This study intended to describe and evaluate the performance of an indirect immunofluorescence assay referred as flow cytometry anti-fixed Leishmania chagasi promastigote IgG antibodies (FC-AFPA-IgG) for serodiagnosis of VL and assessment of post-therapeutic cure. The sera reactivity is reported as the percentage of positive fluorescent parasite (PPFP) along the titration curve. The analysis of sera titration curve indicated the sera dilution 1/32,000 and the PPFP = 25% as the cut-off to segregate positive and negative results. Using these parameters, the FC-AFPA-IgG displayed outstanding sensitivity and specificity for diagnosis and post-therapeutic cure assessment purposes. The inter-test reproducibility of FC-AFPA-IgG was also verified, considering two independent Analysts and validated the results obtained by FC-AFPA-IgG. Moreover, the comparison between FC-AFPA-IgG and the conventional serologic test (ELISA) showed that besides the statistically analogous results with strong positive correlation the FC-AFPA-IgG displayed higher performance indexes. Further analysis demonstrated that while cross-reactivity was observed in 8% of samples tested by ELISA, no cross-reactivity was detected by FC-AFPA-IgG. Together, the findings presented in this study showed the potential of FC-AFPA-IgG in both diagnosis and post-therapeutic cure assessment of VL.
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immunogenicity of a killed Leishmania vaccine with saponin adjuvant in dogs
Vaccine, 2007Co-Authors: Rodolfo Cordeiro Giunchetti, Rodrigo Correaoliveira, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Bruno Mendes Roatt, Rodrigo Dian De Oliveira Aguiarsoares, Juliana Vitoriano De Souza, Nadia Das Dores Moreira, Luiz Cosme Cotta MalaquiasAbstract:Cellular and humoral immune responses of dogs to a candidate vaccine, composed of Leishmania braziliensis promastigote protein plus saponin as adjuvant, have been investigated as a pre-requisite to understanding the mechanisms of immunogenicity against canine visceral Leishmaniasis (CVL). The candidate vaccine elicited strong antigenicity related to the increases of anti-Leishmania IgG isotypes, together with higher levels of lymphocytes, particularly of circulating CD8 + T-lymphocytes and Leishmania chagasi antigen-specific CD8 + T-lymphocytes. As indicated by the intense cell proliferation and increased nitric oxide production during in vitro stimulation by L. chagasi soluble antigens, the candidate vaccine elicited an immune activation status potentially compatible with effective control of the etiological agent of CVL. © 2007 Elsevier Ltd. All rights reserved.
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mixed inflammatory regulatory cytokine profile marked by simultaneous raise of interferon gamma and interleukin 10 and low frequency of tumour necrosis factor alpha monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection
Clinical and Experimental Immunology, 2006Co-Authors: Vanessa Peruhypemagalhaes, Ana Rabello, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Aluizio Prata, L De A Silva, Rosely Moralez De Figueiredo, S F Guimaraescarvalho, Teresa Cristina Abreu FerrariAbstract:Summary Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particu- larly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infec- tion. Although asymptomatic individuals and non-infected subjects pre- sented a similar immunological profile, an outstanding inflammatory/ regulatory profile, based on higher plasmatic levels of cytokines such as inter- leukin (IL)-8, interferon (IFN)- γ , tumour necrosis factor (TNF)- α , IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-Leishmanial mac- rophage activation, associated with the lower frequency of TNF- α + monocytes
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mixed inflammatory regulatory cytokine profile marked by simultaneous raise of interferon gamma and interleukin 10 and low frequency of tumour necrosis factor alpha monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection
Clinical and Experimental Immunology, 2006Co-Authors: Vanessa Peruhypemagalhaes, Ana Rabello, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Aluizio Prata, L De A Silva, Rosely Moralez De Figueiredo, S F Guimaraescarvalho, Teresa Cristina Abreu FerrariAbstract:Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particularly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infection. Although asymptomatic individuals and non-infected subjects presented a similar immunological profile, an outstanding inflammatory/regulatory profile, based on higher plasmatic levels of cytokines such as interleukin (IL)-8, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-Leishmanial macrophage activation, associated with the lower frequency of TNF-alpha(+) monocytes and ordinary levels of nitrite and nitrate are the major mechanisms associated with disease onset.
Teresa Cristina Abreu Ferrari - One of the best experts on this subject based on the ideXlab platform.
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mixed inflammatory regulatory cytokine profile marked by simultaneous raise of interferon gamma and interleukin 10 and low frequency of tumour necrosis factor alpha monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection
Clinical and Experimental Immunology, 2006Co-Authors: Vanessa Peruhypemagalhaes, Ana Rabello, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Aluizio Prata, L De A Silva, Rosely Moralez De Figueiredo, S F Guimaraescarvalho, Teresa Cristina Abreu FerrariAbstract:Summary Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particu- larly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infec- tion. Although asymptomatic individuals and non-infected subjects pre- sented a similar immunological profile, an outstanding inflammatory/ regulatory profile, based on higher plasmatic levels of cytokines such as inter- leukin (IL)-8, interferon (IFN)- γ , tumour necrosis factor (TNF)- α , IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-Leishmanial mac- rophage activation, associated with the lower frequency of TNF- α + monocytes
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mixed inflammatory regulatory cytokine profile marked by simultaneous raise of interferon gamma and interleukin 10 and low frequency of tumour necrosis factor alpha monocytes are hallmarks of active human visceral Leishmaniasis due to Leishmania chagasi infection
Clinical and Experimental Immunology, 2006Co-Authors: Vanessa Peruhypemagalhaes, Ana Rabello, Olindo Assis Martinsfilho, Andrea Teixeiracarvalho, Aluizio Prata, L De A Silva, Rosely Moralez De Figueiredo, S F Guimaraescarvalho, Teresa Cristina Abreu FerrariAbstract:Considering the complexity of the immunological events triggered during active visceral Leishmaniasis (VL), the relevance of the segregation of the immune response during human VL into type 1 and type 2 still remains unclear. For this purpose, in individuals living in risk areas for VL, we have evaluated especially asymptomatic individuals and patients with active VL, the plasmatic levels of cytokines and reactive nitrogen species under ex vivo conditions. In addition, we have also performed an analysis of intracellular cytokine patterns of circulating leucocytes after short-term culture, particularly in the absence of antigenic-specific stimulation, in order to reflect dynamic events of immune response in vivo during Leishmania chagasi infection. Although asymptomatic individuals and non-infected subjects presented a similar immunological profile, an outstanding inflammatory/regulatory profile, based on higher plasmatic levels of cytokines such as interleukin (IL)-8, interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha, IL-6 and IL-10, was associated with clinical status observed in active VL. In this context, we hypothesize that IL-10, through its ability to inhibit anti-Leishmanial macrophage activation, associated with the lower frequency of TNF-alpha(+) monocytes and ordinary levels of nitrite and nitrate are the major mechanisms associated with disease onset.
J G C Hamilton - One of the best experts on this subject based on the ideXlab platform.
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synthetic sex pheromone attracts the Leishmaniasis vector lutzomyia longipalpis diptera psychodidae to traps in the field
Journal of Medical Entomology, 2009Co-Authors: Daniel P Bray, Reginaldo Peçanha Brazil, Krishna K Bandi, A G Oliveira, J G C HamiltonAbstract:ABSTRACT Improving vector control remains a key goal in reducing the world's burden of infectious diseases. More cost-effective approaches to vector control are urgently needed, particularly because vaccines are unavailable and treatment is prohibitively expensive. The causative agent of American visceral Leishmaniasis (AVL), Leishmania chagasi, Cunha and Chagas (Kinetoplastida: Trypanosomatidae), is transmitted between animal and human hosts by blood-feeding female sand flies attracted to mating aggregations formed on or above host animals by male-produced sex pheromones. Our results show the potential of using synthetic pheromones to control populations of Lutzomyia longipalpis Lutz and Neiva (Diptera: Psychodidae), the sand fly vector of one of the world's most important neglected diseases, AVL. We showed that a synthetic pheromone, (±) -9-methylger-macrene-B, produced from a low-cost plant intermediate, attracted females in the laboratory. By formulating dispensers that released this pheromone at a ra...
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a real time pcr assay to estimate Leishmania chagasi load in its natural sand fly vector lutzomyia longipalpis
Transactions of The Royal Society of Tropical Medicine and Hygiene, 2008Co-Authors: Shalindra Ranasinghe, J G C Hamilton, Matthew E Rogers, Paul A Bates, R. MaingonAbstract:Leishmania chagasi, transmitted mainly by Lutzomyia longipalpis sand flies, causes visceral Leishmaniasis and atypical cutaneous Leishmaniasis in Latin America. Successful vector control depends upon determining vectorial capacity and understanding Leishmania transmission by sand flies. As microscopic detection of Leishmania in dissected sand fly guts is laborious and time-consuming, highly specific, sensitive, rapid and robust Leishmania PCR assays have attracted epidemiologists' attention. Real-time PCR is faster than qualitative PCR and yields quantitative data amenable to statistical analyses. A highly reproducible Leishmania DNA polymerase gene-based TaqMan real-time PCR assay was adapted to quantify Leishmania in sand flies, showing intra-assay and inter-assay coefficient variations lower than 1 and 1.7%, respectively, and sensitivity to 10 pg Leishmania DNA ( approximately 120 parasites) in as much as 100 ng sand fly DNA. Data obtained for experimentally infected sand flies yielded parasite loads within the range of counts obtained by microscopy for the same sand fly cohort or that were around five times higher than microscopy counts, depending on the method used for data analysis. These results highlight the potential of quantitative PCR for Leishmania transmission studies, and the need to understand factors affecting its sensitivity and specificity.
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the lutzomyia longipalpis species complex does population sub structure matter to Leishmania transmission
Trends in Parasitology, 2008Co-Authors: R. Maingon, R. D. Ward, J G C Hamilton, Alexandre A. PeixotoAbstract:Leishmania chagasi causes visceral Leishmaniasis and, to a lesser extent, atypical cutaneous Leishmaniasis in Central and South America. Its main sand fly vector, Lutzomyia longipalpis s.l. (Diptera: Psychodidae) displays a complex population structure that might contribute to the observed clinical pleomorphism and to recent major urban epidemics. This article summarises our understanding on reproductive barriers and hybridisation among this vector's sibling incipient species. Identifying genes important for sand fly ecological adaptability and sand fly– Leishmania genetic co-variation could be helpful for interrupting Leishmania transmission.