scholarly journals Assessment of PCR in the detection of Leishmania spp in experimentally infected individual phlebotomine sandflies (Diptera: Psychodidae: Phlebotominae)

2002 ◽  
Vol 44 (5) ◽  
pp. 255-259 ◽  
Author(s):  
Érika M. MICHALSKY ◽  
Consuelo L. FORTES-DIAS ◽  
Paulo F.P. PIMENTA ◽  
Nágila F.C. SECUNDINO ◽  
Edelberto S. DIAS

DNA amplification by the polymerase chain reaction (PCR) was applied in the investigation of the presence of Leishmania (Kinetoplastida: Trypanosomatidae) parasites in single phlebotomine sandflies. Three phlebotomine/parasite pairs were used: Lutzomyia longipalpis/Leishmania chagasi, Lutzomyia migonei/Leishmania amazonensis and Lutzomyia migonei/Leishmania braziliensis, all of them incriminated in the transmission of visceral or cutaneous leishmaniasis. DNA extraction was performed with whole insects, with no need of previous digestive tract dissection or pooling specimens. The presence of either mouse blood in the digestive tract of the sandflies or the digestive tract itself did not interfere in the PCR. Infection by as few as 10 Leishmania sp. per individual were sufficient for DNA amplification with genus-specific primers. Using primers for L. braziliensis and L. mexicana complexes, respectively, it was possible to discriminate between L. braziliensis and L. amazonensis in experimentally infected vectors (L. migonei).

2007 ◽  
Vol 23 (5) ◽  
pp. 1227-1232 ◽  
Author(s):  
Maria Rosimery de Carvalho ◽  
Bruna Santos Lima ◽  
José Ferreira Marinho-Júnior ◽  
Fernando José da Silva ◽  
Hélio França Valença ◽  
...  

The aim of this study was to identify the fauna of phlebotomine sandflies in an area with incidence of American visceral leishmaniasis (AVL) in São Vicente Férrer, a municipality (county) located in the northern Zona da Mata in Pernambuco State, Brazil. Sandfly captures were conducted monthly for four nights/month from December 2002 to November 2003, by means of manual captures (with a Shannon trap) and by CDC light traps. A total of 23,156 specimens of phlebotomines sandflies were collected in a remnant of the Atlantic rainforest, houses, and animal shelters. Lutzomyia complexa was the most prevalent species, with a frequency of 62.5% (14,445/23,156), followed by Lutzomyia migonei, with 33.2% (7,677/23,156). No Lutzomyia longipalpis (the main vector of Leishmania chagasi in Brazil and the Americas) was found in the target area. Some specimens were dissected, but no Leishmania parasites were found.


2012 ◽  
Vol 45 (6) ◽  
pp. 754-756 ◽  
Author(s):  
Marco André Loureiro Tonini ◽  
Elenice Moreira Lemos ◽  
Alexandre Barbosa Reis ◽  
Wendel Coura Vital ◽  
Edelberto Santos Dias ◽  
...  

INTRODUCTION: We investigated autochthonous canine visceral leishmaniasis (CVL) in the metropolitan region of Vitória (MRV), an area in which a human case was previously reported. METHODS: Serological, parasitological, and molecular tests were performed in 201 dogs. RESULTS: Twenty-six (13%) and 12 (6%) dogs were identified as positive using in-house enzyme-linked immunosorbent assay (ELISA) and rK39 tests, respectively. Two dogs had a positive culture for Leishmania chagasi, and 4 were polymerase chain reaction (PCR)-positive for Leishmania spp. One positive dog belonged to the aforementioned patient. CONCLUSIONS: Although the responsible vector was not found, our results provide evidence of autochthonous CVL in the MRV, a non-endemic area for VL.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Júlia Alves Menezes ◽  
Eduardo de Castro Ferreira ◽  
José Dilermando Andrade-Filho ◽  
Alessandra Mara de Sousa ◽  
Mayron Henrique Gomes Morais ◽  
...  

Some epidemiological aspects of leishmaniasis in the municipality of Formiga, Brazil, an important touristic site, were evaluated. Those included phlebotomine sand fly vectors, canine infection, and geoprocessing analysis for determining critical transmission areas. Sand flies (224 insects) belonging to ten different species were captured. The most captured species includedLutzomyia longipalpis(35.3%),Lutzomyia cortelezzii(33.5%), andLutzomyia whitmani(18.3%). A significant correlation between sand fly densities and climatic conditions was detected. Serological diagnosis (DPP and ELISA) was performed in 570 dogs indicating a prevalence of 5.8%. After sequencing the main species circulating in the area wereLeishmania infantumandLeishmania braziliensis. Spatial analysis demonstrated that vegetation and hydrography may be related to sand fly distribution and infected dogs. The municipality of Formiga has proven leishmaniasis vectors and infected dogs indicating the circulation of the parasite in the city. Correlation of those data with environmental and human cases has identified the critical areas for control interventions (south, northeast, and northwest). In conclusion, there is current transmission of visceral and canine human cases and the city is on the risk for the appearance of cutaneous cases.


2004 ◽  
Vol 18 (16) ◽  
pp. 775-784 ◽  
Author(s):  
DIETER BRAUN

The Polymerase Chain Reaction (PCR) allows for highly sensitive and specific amplification of DNA. It is the backbone of many genetic experiments and tests. Recently, three labs independently uncovered a novel and simple way to perform a PCR reaction. Instead of repetitive heating and cooling, a temperature gradient across the reaction vessel drives thermal convection. By convection, the reaction liquid circulates between hot and cold regions of the chamber. The convection triggers DNA amplification as the DNA melts into two single strands in the hot region and replicates into twice the amount in the cold region. The amplification progresses exponentially as the convection moves on. We review the characteristics of the different approaches and show the benefits and prospects of the method.


Genome ◽  
1993 ◽  
Vol 36 (4) ◽  
pp. 686-693 ◽  
Author(s):  
Benoit Van Coppenolle ◽  
Iwao Watanabe ◽  
Charles Van Hove ◽  
Gerard Second ◽  
Ning Huang ◽  
...  

The polymerase chain reaction was used to amplify random sequences of DNA from 25 accessions of Azolla to evaluate the usefulness of this technique for identification and phylogenetic analysis of this aquatic fern. Accessions were selected to represent all known species within the genus Azolla and to encompass the worldwide distribution of the fern. Primers of 10 nucleotides with 70% G + C content were used to generate randomly amplified polymorphic DNA from the symbiotic Azolla–Anabaena complex. Twenty-two primers were used and each primer gave 4–10 bands of different molecular weights for each accession. Bands were scored as present or absent for each accession and variation among accessions was quantified using Nei's genetic distances. A dendrogram summarizing phenetic relationships among the 25 accessions was generated using the unweighted pair-group method with arithmetic mean. Principal component analysis was also used to evaluate genetic similarities. Three distinct groups were identified: group 1 contains five species, group 2 contains the pinnata species, and group 3 contains the nilotica species. The analysis demonstrates that the major groups of Azolla species can be easily distinguished from one an other and, in addition, that closely related accessions within species can be identified. We further found that using 10 primers, a phylogeny that is essentially the same as that derived from 22 primers can be constructed. Our results suggest that total DNA extracted from the Azolla–Anabaena symbionts is useful for classification and phylogenetic studies of Azolla.Key words: Azolla–Anabaena symbiosis, genetic distances, polymerase chain reaction, principal component analysis.


2016 ◽  
Vol 95 (3) ◽  
pp. 133
Author(s):  
Luilson Geraldo Coelho Junior ◽  
Alessandra De Paiva Wanderley ◽  
Maire Stefani Lemes ◽  
Bárbara Cristina Dos Santos Ribeiro Leite ◽  
Bárbara Keroleny Viana Cabrobó ◽  
...  

leishmaniose visceral (LV) é uma infecção causada por protozoários tripanosomatídeos do gênero Leishmania, as espécies são: Leishmania donovani e Leishmania infantum (conhecido como Leishmania chagasi na América do Sul). A LV é uma doença parasitária grave, com elevada morbimortalidade em todo o mundo. É considerada a doença tropical mais negligenciada, em termos de desenvolvimento de novos medicamentos. Considerada um importante problema de saúde em todo o Brasil, principalmente na área endêmica de Paracatu-MG. Acomete principalmente crianças com menos de cinco anos de idade. A transmissão ocorre através da picada de fêmeas hematófagas dos vetores Lutzomyia longipalpis ou L. cruzi, infectados pela Leishmania (L.) chagasi. Os sinais clínicos da LV variam de acordo com a resposta imune do hospedeiro, podendo assumir formas assintomáticas, oligossintomáticas e a forma clássica; os principais sinais incluem febre, hepatoesplenomegalia, perda de peso e pancitopenia. Indivíduos não tratados, crianças desnutridas, indivíduos infectados pelo HIV ou em uso de drogas imunossupressoras são grupos de risco, sendo que nesses casos a LV apresenta alta letalidade. O diagnóstico é feito através da demonstração da Leishmania em aspirados de linfonodo, medula óssea e baço; por meio de sorologia, ou teste rápido como o rK39, são amplamente utilizados, e apresentam sensibilidade variável. O tratamento é realizado com antimoniais pentavalentes e anfotericina B lipossomal ou desoxicolato. Não há vacina humana; portanto o combate ao vetor é a melhor medida de prevenção. Relatamos um caso de LV em criança de 04 anos de idade, natural e procedente de Paracatu-MG.


2014 ◽  
Vol 23 (3) ◽  
pp. 320-327 ◽  
Author(s):  
Rafaella Albuquerque Silva ◽  
Fabricio Kassio Moura Santos ◽  
Lindemberg Caranha de Sousa ◽  
Elizabeth Ferreira Rangel ◽  
Claudia Maria Leal Bevilaqua

The main vector for visceral leishmaniasis (VL) in Brazil is Lutzomyia longipalpis. However, the absence of L. longipalpis in a region of autochthonous VL demonstrates the participation of other species in the transmission of the parasite. Studies conducted in La Banda, Argentina, and São Vicente Férrer, Pernambuco State, Brazil, have correlated the absence of L. longipalpisand the presence of L. migonei with autochthonous cases of VL. In São Vicente Férrer, Pernambuco, there was evidence for the natural infection of L. migonei with Leishmania infantum chagasi. Thus, the objective of this work was to assess the ecology of the sand flies L. longipalpis and L. migonei in Fortaleza, an endemic area for VL. Insect capture was conducted at 22 sampling points distributed across four regions of Fortaleza. In total, 32,403 sand flies were captured; of these, 18,166 (56%) were identified as L. longipalpis and 14,237 (44%) as L. migonei. There were significant density differences found between the vectors at each sampling site (indoors and outdoors) (p <0.0001). These findings confirm that L. migonei and L. longipalpis are distributed throughout Fortaleza, where they have adapted to an indoor environment, and suggest that L. migonei may share the role as a vector with L. longipalpis in the transmission of VL in Fortaleza.


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