27 research outputs found

    Genomic analysis of two phlebotomine sand fly vectors of Leishmania from the New and Old World.

    Get PDF
    Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites

    Sand fly synthetic sex-aggregation pheromone co-located with insecticide reduces the incidence of infection in the canine reservoir of visceral leishmaniasis: a stratified cluster randomised trial

    Get PDF
    The predominant sand fly vector of the intracellular parasite Leishmania infantum, that causes human and canine visceral leishmaniasis in the Americas, is Lutzomyia longipalpis. Dogs are the proven reservoir. Vector control tools to reduce transmission suited to this predominantly exophilic vector are lacking. Insecticide-impregnated dog collars protect dogs against infectious bites from sand fly vectors, and result in reductions of new infections in both dogs and humans. However, collars are costly for endemic communities, and alternative approaches are needed. Recently the bulk synthesised sex-aggregation pheromone of male Lu. longipalpis was shown to attract large numbers of conspecific females to lethal pyrethroid insecticides, indicating the potential for use in a vector control application. This study, conducted in Brazil, evaluated the efficacy of this novel lure-and-kill approach to reduce seroconversion and infection incidence with L. infantum in the canine reservoir, in addition to measuring its impact on household abundance of Lu. longipalpis. Deployed in 14 stratified clusters, the outcomes were compared to those attributed to insecticide impregnated collars fitted to dogs in another 14 clusters; each intervention was compared to 14 clusters that received placebo treatments. The beneficial effects of the lure-and-kill method were most noticeable on confirmed infection incidence and clinical parasite loads, and in reducing sand fly abundance. The overall effect of the two interventions were not statistically dissimilar, though the confidence intervals were broad. We conclude that the novel low-cost lure-and-kill approach should be added to the vector control toolbox against visceral leishmaniasis in the Americas

    Integrated systems for biopolymers and bioenergy production from organic waste and by-products: a review of microbial processes

    Full text link
    corecore