552 research outputs found

    Detección de ADN de kinetoplasto en vectores y posibles vectores de leishmaniasis en cuatro localidades de las provincias de Esmeraldas y Manabí

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    Leishmania is a protozoan hemoflagellate belong to the Kinetoplastida order and Trypanosomatidae family transmitted to the human through the bite of a female sandfly of the Phlebotominae subfamily. The amastigotes introduced into the skin are responsible for the cutaneous, mucocutaneous or visceral lesions characteristic of the zoonotic disease called leishmaniasis. In Ecuador, leishmaniasis is present in 22 of the 24 provinces. Most of the reported cases are cutaneous Leishmaniasis, especially in areas where the natural habitat of the vectors is invading and in low-income populations. In this study, we detected the presence of kinetoplast DNA by real-time PCR in 252 specimens belonging to 6 species of vectors and possible vectors of leishmaniasis collected in 3 localities of the province of Esmeraldas and one locality of Manabi in order to understand the dynamics of transmission of this disease. An infection rate of 3.25% for Endotrypanum was found in Ps. panamensis and Ny.trapidoi both species considered vectors of leishmaniasis.La Leishmania es un protozoario hemoflagelado del orden Kinetoplastida y de la familia Trypanosomatidae que se transmite al ser humano a través de la picadura de un díptero hembra de la subfamilia Phlebotominae. Los amastigotes introducidos en la piel son los causantes de las lesiones cutáneas, mucocutaneas o viscerales características de la enfermedad zoonótica llamada leishmaniasis. En el Ecuador, la leishmaniasis está presente en 22 de las 24 provincias. La mayoría de los casos que se han reportado corresponden a Leishmaniasis cutánea sobre todo en zonas donde se invade el hábitat natural de los vectores y en poblaciones de bajos recursos. En este estudio se detectó la presencia de ADN de kinetoplasto por PCR en tiempo real en 252 especímenes pertenecientes a 6 especies de vectores y posibles vectores de leishmaniasis colectados en 3 localidades de la provincia de Esmeraldas y una localidad de Manabí para entender la dinámica de transmisión de la enfermedad. Se encontró una tasa de infección de 3,25% para Endotrypanum en Ps. panamensis y Ny. trapidoi ambas especies consideradas vectores de leishmaniasis

    Leishmania tarentolae: taxonomic classification and its application as a promising biotechnological expression host

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    In this review, we summarize the current knowledge concerning the eukaryotic protozoan parasite Leishmania tarentolae, with a main focus on its potential for biotechnological applications. We will also discuss the genus, subgenus, and species-level classification of this parasite, its life cycle and geographical distribution, and similarities and differences to human-pathogenic species, as these aspects are relevant for the evaluation of biosafety aspects of L. tarentolae as host for recombinant DNA/protein applications. Studies indicate that strain LEM-125 but not strain TARII/UC of L. tarentolae might also be capable of infecting mammals, at least transiently. This could raise the question of whether the current biosafety level of this strain should be reevaluated. In addition, we will summarize the current state of biotechnological research involving L. tarentolae and explain why this eukaryotic parasite is an advantageous and promising human recombinant protein expression host. This summary includes overall biotechnological applications, insights into its protein expression machinery (especially on glycoprotein and antibody fragment expression), available expression vectors, cell culture conditions, and its potential as an immunotherapy agent for human leishmaniasis treatment. Furthermore, we will highlight useful online tools and, finally, discuss possible future applications such as the humanization of the glycosylation profile of L. tarentolae or the expression of mammalian recombinant proteins in amastigotelike cells of this species or in amastigotes of avirulent human-pathogenic Leishmania species

    Leishmaniasis: A review of the disease and the debate over the origin and dispersal of the causaitive parasite Leishmania

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    The vector borne disease Leishmaniasis, caused by the Leishmania parasite, is estimated to affect the lives of 12 million people. Manifesting itself into three different clinical forms that center on disfiguring sores and enlargement of several organs, Leishmaniasis is a devastating disease impairing economic productivity and impeding socioeconomic development. The complex life cycle of this parasite, involving a host, vector, and reservoir, has played a major role in defining the dispersal and prevalence of this disease on a global level. The prevalence of Leishmaniasis is highly concentrated due to the close relationship of this parasite and its single vector (the female Phlebotomine sand fly), and the socioeconomic and environmental factors that are beneficial to the sand fly habitat. Yet, there is a wide and varied distribution of Leishmania species. Some species belonging to the subgenera of Leishmania are found in both Old and New Worlds, while others belonging to the subgenera Viannia are found only in the New World. Interest in the origin and dispersal of Leishmania has risen from this disjointed distribution and a need for a complete comprehensive understanding of this parasite in order to determine the best approach in the eradication of this disease. The two main hypotheses from the literature that have become established in this debate are a Palaearctic origin and a Neotropical origin. These hypotheses are presented along with a third hypothesis of an African and Neotropical origin. The conflicts between molecular, entomological, biogeographical, and ecological data, along with insufficient research that have rendered this debate unresolved are also discussed. Complexity of this diseases’ epidemiological cycle demands a comprehensive understanding of the parasite, including its origin and dispersal, to maintain the most effective prevention, treatment, and hopefully eradication

    A historical overview of the classification, evolution, and dispersion of Leishmania parasites and sandflies

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    Background The aim of this study is to describe the major evolutionary historical events among Leishmania, sandflies, and the associated animal reservoirs in detail, in accordance with the geographical evolution of the Earth, which has not been previously discussed on a large scale. Methodology and Principal Findings Leishmania and sandfly classification has always been a controversial matter, and the increasing number of species currently described further complicates this issue. Despite several hypotheses on the origin, evolution, and distribution of Leishmania and sandflies in the Old and New World, no consistent agreement exists regarding dissemination of the actors that play roles in leishmaniasis. For this purpose, we present here three centuries of research on sandflies and Leishmania descriptions, as well as a complete description of Leishmania and sandfly fossils and the emergence date of each Leishmania and sandfly group during different geographical periods, from 550 million years ago until now. We discuss critically the different approaches that were used for Leishmana and sandfly classification and their synonymies, proposing an updated classification for each species of Leishmania and sandfly. We update information on the current distribution and dispersion of different species of Leishmania (53), sandflies (more than 800 at genus or subgenus level), and animal reservoirs in each of the following geographical ecozones: Palearctic, Nearctic, Neotropic, Afrotropical, Oriental, Malagasy, and Australian. We propose an updated list of the potential and proven sandfly vectors for each Leishmania species in the Old and New World. Finally, we address a classical question about digenetic Leishmania evolution: which was the first host, a vertebrate or an invertebrate? Conclusions and Significance We propose an updated view of events that have played important roles in the geographical dispersion of sandflies, in relation to both the Leishmania species they transmit and the animal reservoirs of the parasites

    First isolation of Leishmania from Northern Thailand:case report, identification as Leishmania martiniquensis and phylogenetic position within the Leishmania enriettii complex

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    Since 1996, there have been several case reports of autochthonous visceral leishmaniasis in Thailand. Here we report a case in a 52-year-old Thai male from northern Thailand, who presented with subacute fever, huge splenomegaly and pancytopenia. Bone marrow aspiration revealed numerous amastigotes within macrophages. Isolation of Leishmania LSCM1 into culture and DNA sequence analysis (ribosomal RNA ITS-1 and large subunit of RNA polymerase II) revealed the parasites to be members of the Leishmania enriettii complex, and apparently identical to L. martiniquensis previously reported from the Caribbean island of Martinique. This is the first report of visceral leishmaniasis caused by L. martiniquensis from the region. Moreover, the majority of parasites previously identified as "L. siamensis" also appear to be L. martiniquensis

    The history of leishmaniasis

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    In this review article the history of leishmaniasis is discussed regarding the origin of the genus Leishmania in the Mesozoic era and its subsequent geographical distribution, initial evidence of the disease in ancient times, first accounts of the infection in the Middle Ages, and the discovery of Leishmania parasites as causative agents of leishmaniasis in modern times. With respect to the origin and dispersal of Leishmania parasites, the three currently debated hypotheses (Palaearctic, Neotropical and supercontinental origin, respectively) are presented. Ancient documents and paleoparasitological data indicate that leishmaniasis was already widespread in antiquity. Identification of Leishmania parasites as etiological agents and sand flies as the transmission vectors of leishmaniasis started at the beginning of the 20th century and the discovery of new Leishmania and sand fly species continued well into the 21st century. Lately, the Syrian civil war and refugee crises have shown that leishmaniasis epidemics can happen any time in conflict areas and neighbouring regions where the disease was previously endemic

    Leishmania siamensis als Erreger von autochthoner kutaner Leishmaniose bei Pferden in Deutschland - eine neue Infektionskrankheit in Mitteleuropa?

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    Aus mitteleuropäischer Sicht ist die durch Parasiten verursachte und von Sandmücken übertragene Leishmaniose eine in Ländern tropischer und subtropischer Regionen auftretende Infektionskrankheit. In zunehmendem Maße werden jedoch autochthone Fälle in Mitteleuropa, insbesondere in Süddeutschland, verzeichnet. Dies ist vermutlich auf die globale Erwärmung und die Ausdehnung des Verbreitungsgebietes der Sandmücken nach Norden zurückzuführen. Die vorliegende Arbeit befasst sich mit der Identifizierung und phylogenetischen Charakterisierung der Erreger dieser Fälle. Dazu wurden verschiedene Marker im Leishmaniengenom sequenziert und mit bekannten Arten verglichen. Die untersuchte DNA stammte von autochthonen kutanen Leishmaniosen bei Pferden und einem Rind, die in den letzten zehn Jahren in Deutschland und der Schweiz auftraten. Aufgrund identischer Sequenzen konnten die Parasiten als L. siamensis identifiziert bzw. verifiziert werden, eine erst im Jahr 2008 neu beschriebene Art, die in Thailand humane viszerale Leishmaniose verursacht. Die phylogenetischen Analysen zeigten die Ähnlichkeit von L. siamensis mit weiteren bisher nicht identifizierten Stämmen aus Martinique und Ghana, die kutane Leishmaniose bei Menschen verursachen. Um die Frage zu beantworten, ob sich die Leishmaniose zu einer in Mitteleuropa endemischen zoonotischen Krankheit entwickeln könnte, müssen weitere Studien über kompatible Vektoren, mögliche Reservoire und zur Virulenz durchgeführt werden

    Phlebotomine fauna (Diptera: Psychodidae) of an American cutaneous leishmaniasis endemic area in the state of Mato Grosso do Sul, Brazil

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    The occurrence of an outbreak of cutaneous leishmaniasis associated with Leishmania (Leishmania) amazonensis in the municipality of Bela Vista, state of Mato Grosso do Sul, Brazil, and the absence of information on its vectors in this area led the authors to undertake captures of phlebotomine sand flies, using Shannon traps and automatic CDC light traps, in domiciles, forested areas and animal shelters from February 2004-January 2006. A total of 808 specimens belonging to 18 sandfly species have been identified: Bichromomyia flaviscutellata,Brumptomyia avellari, Brumptomyia brumpti, Brumptomyia sp, Evandromyia aldafalcaoae, Evandromyia cortelezzii, Evandromyia evandroi, Evandromyia lenti, Evandromyia teratodes, Evandromyia termitophila, Lutzomyia longipalpis, Nyssomyia whitmani, Pintomyia christenseni, Psathyromyia aragaoi, Psathyromyia campograndensis, Psathyromyia punctigeniculata, Psathyromyia shannoni and Sciopemyia sordellii. The presence of Lu. longipalpis, Ny. whitmani and Bi. flaviscutellata, vectors of Leishmania chagasi, Leishmania braziliensis and L. amazonensis, respectively, has increased.FUNDECT - DECIT Departamento de Ciência e Tecnologia do Ministério da Saúd
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