Leishmania is a genus of the family Trypanosomatidae that unites obligatory parasitic flagellates causing a variety of vector-borne diseases collectively called leishmaniasis. The symptoms range from relatively innocuous skin lesions to complete failures of visceral organs. The disease is exacerbated if a parasite harbors Leishmania RNA viruses (LRVs) of the family Pseudototiviridae.
View Article and Find Full Text PDFBackground: Several new species of Leishmania have recently emerged in Europe, probably as the result of global changes and increased human migration from endemic areas. In this study, we tested whether two sand fly species, the Western Mediterranean Phlebotomus perniciosus and the Eastern Mediterranean P. tobbi, are competent vectors of L.
View Article and Find Full Text PDFLeishmania species, members of the kinetoplastid parasites, cause leishmaniasis, a neglected tropical disease, in millions of people worldwide. Leishmania has a complex life cycle with multiple developmental forms, as it cycles between a sand fly vector and a mammalian host; understanding their life cycle is critical to understanding disease spread. One of the key life cycle stages is the haptomonad form, which attaches to insect tissues through its flagellum.
View Article and Find Full Text PDFThe leishmaniases are globally important parasitic diseases for which no human vaccines are currently available. To facilitate vaccine development, we conducted an open-label observational study to establish a controlled human infection model (CHIM) of sand fly-transmitted cutaneous leishmaniasis (CL) caused by Leishmania major. Between 24 January and 12 August 2022, we exposed 14 participants to L.
View Article and Find Full Text PDFLeishmania major is responsible for zoonotic cutaneous leishmaniasis. Therapy is mainly based on the use of antimony-based drugs; however, treatment failures and illness relapses were reported. Although studies were developed to understand mechanisms of drug resistance, the interactions of resistant parasites with their reservoir hosts and vectors remain poorly understood.
View Article and Find Full Text PDFLeishmania, the dixenous trypanosomatid parasites, are the causative agents of leishmaniasis currently divided into four subgenera: Leishmania, Viannia, Sauroleishmania, and the recently described Mundinia, consisting of six species distributed sporadically all over the world infecting humans and/or animals. These parasites infect various mammalian species and also cause serious human diseases, but their reservoirs are unknown. Thus, adequate laboratory models are needed to enable proper research of Mundinia parasites.
View Article and Find Full Text PDFNearly all aerobic organisms are equipped with catalases, powerful enzymes scavenging hydrogen peroxide and facilitating defense against harmful reactive oxygen species. In trypanosomatids, this enzyme was not present in the common ancestor, yet it had been independently acquired by different lineages of monoxenous trypanosomatids from different bacteria at least three times. This observation posited an obvious question: why was catalase so "sought after" if many trypanosomatid groups do just fine without it? In this work, we analyzed subcellular localization and function of catalase in Leptomonas seymouri.
View Article and Find Full Text PDFIn Uzbekistan, the number of reported leishmaniasis cases is rising at the alarming rate. In this work, we studied the phlebotomine sand fly (Diptera: Phlebotominae) diversity in the foci of cutaneous leishmaniasis in the Surxondaryo Region of Uzbekistan and compared it with the data obtained for the same area 50 years ago, when infection prevalence was reportedly low. We found that the implicated vector for zoonotic leishmaniasis, P.
View Article and Find Full Text PDFThe unicellular parasite Leishmania has a precisely defined cell architecture that is inherited by each subsequent generation, requiring a highly coordinated pattern of duplication and segregation of organelles and cytoskeletal structures. A framework of nuclear division and morphological changes is known from light microscopy, yet this has limited resolution and the intrinsic organisation of organelles within the cell body and their manner of duplication and inheritance is unknown. Using volume electron microscopy approaches, we have produced three-dimensional reconstructions of different promastigote cell cycle stages to give a spatial and quantitative overview of organelle positioning, division and inheritance.
View Article and Find Full Text PDFSand fly transmitted Leishmania species are responsible for severe, wide ranging, visceral and cutaneous leishmaniases. Genetic exchange can occur among natural Leishmania populations and hybrids can now be produced experimentally, with limitations. Feeding Phlebotomus orientalis or Phlebotomus argentipes on two strains of Leishmania donovani yielded hybrid progeny, selected using double drug resistance and fluorescence markers.
View Article and Find Full Text PDFAttachment to a substrate to maintain position in a specific ecological niche is a common strategy across biology, especially for eukaryotic parasites. During development in the sand fly vector, the eukaryotic parasite adheres to the stomodeal valve, as the specialised haptomonad form. Dissection of haptomonad adhesion is a critical step for understanding the complete life cycle of .
View Article and Find Full Text PDFCutaneous leishmaniasis (CL) is the most important neglected disease reported in North Africa, Algeria ranks second in the world with more than 5000 cases per year. In Algeria, two rodent species and are so far known as proven reservoirs of , however, they are absent in several endemic localities. In this study, we experimentally infected rodents trapped around human dwellings in Illizi, Algeria to assess their susceptibility to .
View Article and Find Full Text PDFLeishmaniases are neglected diseases caused by protozoans of the genus that threaten millions of people worldwide. Cutaneous leishmaniasis (CL) caused by is a typical zoonosis transmitted by phlebotomine sand flies and maintained in rodent reservoirs. The female sand fly was assumed to become infected by feeding on the skin lesion of the host, and the relative contribution of asymptomatic individuals to disease transmission was unknown.
View Article and Find Full Text PDFBackground: Sergentomyia minuta (Diptera: Phlebotominae) is an abundant sand fly species in the Mediterranean basin and a proven vector of reptile parasite Leishmania (Sauroleishmania) tarentolae. Although it feeds preferentially on reptiles, blood meal analyses and detection of Leishmania (Leishmania) infantum DNA in wild-caught S. minuta suggest that occasional feeding may occur on mammals, including humans.
View Article and Find Full Text PDFTrypanosomatid pathogens are transmitted by blood-feeding insects, causing devastating human infections. These parasites show important phenotypic shifts that often impact parasite pathogenicity, tissue tropism, or drug susceptibility. The evolutionary mechanisms that allow for the selection of such adaptive phenotypes remain only poorly investigated.
View Article and Find Full Text PDFIn this work we reviewed historical and recent data on spp. infection combining data collected in Turkmenistan, Uzbekistan, Kazakhstan, Kyrgyzstan, Iran, China and Mongolia. We specifically focused on a complex of co-existing species (, and ) sharing the same animal reservoirs and vectors.
View Article and Find Full Text PDFParasites of the genus , together with the genus , form a sister clade to the species-rich and medically important genus . Both species, and , are dixenous parasites of Neotropical porcupines. Almost 50 years after their first discovery, knowledge of their life cycle remains poor and their insect vectors are unknown.
View Article and Find Full Text PDFBackground: Species belonging to the subgenus Sauroleishmania are parasites of reptiles, and traditionally considered to be non-pathogenic to mammals. Knowledge of the development of these parasites in sand flies and their mechanism of transmission is currently lacking. The main aim of this study was to test the susceptibility of various sand fly species to infection by two Sauroleishmania species, focusing on the localization of parasites in the sand fly intestinal tract.
View Article and Find Full Text PDFLeishmaniasis is a parasitic vector-borne disease caused by the protistan flagellates of the genus Leishmania. Leishmania (Viannia) guyanensis is one of the most common causative agents of the American tegumentary leishmaniasis. It has previously been shown that L.
View Article and Find Full Text PDFThe protozoan parasite Leishmania donovani causes fatal human visceral leishmaniasis in absence of treatment. Genome instability has been recognized as a driver in Leishmania fitness gain in response to environmental change or chemotherapy. How genome instability generates beneficial phenotypes despite potential deleterious gene dosage effects is unknown.
View Article and Find Full Text PDF() is transmitted by reptile-biting sand flies of the genus , but the role of sand flies in circulation of this parasite is unknown. Here, we compared the development of () strains in three species: , , and . Laboratory-bred sand flies were membrane-fed on blood with parasite suspension and dissected on days 1 and 7 post blood meal.
View Article and Find Full Text PDFLeishmaniasis is a globally important yet neglected parasitic disease transmitted by phlebotomine sand flies. With new candidate vaccines in or near the clinic, a controlled human challenge model (CHIM) using natural sand fly challenge would provide a method for early evaluation of prophylactic efficacy. We evaluated the biting frequency and adverse effects resulting from exposure of human volunteers to bites of either or , two natural vectors of .
View Article and Find Full Text PDFLeishmania parasites, causative agents of leishmaniasis, are currently divided into four subgenera: Leishmania, Viannia, Sauroleishmania and Mundinia. The recently established subgenus Mundinia has a wide geographical distribution and contains five species, three of which have the potential to infect and cause disease in humans. While the other Leishmania subgenera are transmitted exclusively by phlebotomine sand flies (Diptera: Psychodidae), natural vectors of Mundinia remain uncertain.
View Article and Find Full Text PDFWhile numerous genomes of spp. have been sequenced and analyzed, an understanding of the evolutionary history of these organisms remains limited due to the unavailability of the sequence data for their closest known relatives, and spp., infecting sloths and porcupines.
View Article and Find Full Text PDFCatalase is one of the most abundant enzymes on Earth. It decomposes hydrogen peroxide, thus protecting cells from dangerous reactive oxygen species. The catalase-encoding gene is conspicuously absent from the genome of most representatives of the family Trypanosomatidae.
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