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PLoS Neglected Tropical Diseases Oct 2020The microbial consortium associated with sandflies has gained relevance, with its composition shifting throughout distinct developmental stages, being strongly...
The microbial consortium associated with sandflies has gained relevance, with its composition shifting throughout distinct developmental stages, being strongly influenced by the surroundings and food sources. The bacterial components of the microbiota can interfere with Leishmania development inside the sandfly vector. Microbiota diversity and host-microbiota-pathogen interactions regarding New World sandfly species have yet to be thoroughly studied, particularly in Lutzomyia longipalpis, the primary vector of visceral leishmaniasis in Brazil.The native microbiota of different developmental stages and physiological conditions of Lu. longipalpis (Lapinha Cave), was described by culturing and 16s rRNA gene sequencing. The 16s rRNA sequencing of culture-dependent revealed 13 distinct bacterial genera (Bacillus, Enterococcus, Erwinia, Enterobacter, Escherichia, Klebsiella, Lysinibacillus, Pseudocitrobacter, Providencia, Pseudomonas, Serratia, Staphylococcus and Solibacillus). The in vitro and in vivo effects of each one of the 13 native bacteria from the Lu. longipalpis were analyzed by co-cultivation with promastigotes of L.i. chagasi, L. major, L. amazonensis, and L. braziliensis. After 24 h of co-cultivation, a growth reduction observed in all parasite species. When the parasites were co-cultivated with Lysinibacillus, all parasites of L. infantum chagasi and L. amazonensis died within 24 hours. In the in vivo co-infection of L.chagasi, L. major and L. amazonensis with the genera Lysinibacillus, Pseudocitrobacter and Serratia it was possible to observe a significant difference between the groups co-infected with the bacterial genera and the control group.These findings suggest that symbiont bacteria (Lysinibacillus, Serratia, and Pseudocitrobacter) are potential candidates for paratransgenic or biological control. Further studies are needed to identify the nature of the effector molecules involved in reducing the vector competence for Leishmania.
Topics: Animals; Bacteria; Leishmania; Microbiota; Psychodidae; RNA, Bacterial; RNA, Ribosomal, 16S
PubMed: 33052941
DOI: 10.1371/journal.pntd.0008666 -
PLoS Neglected Tropical Diseases Aug 2021Phlebotomine sand flies are prominent vectors of Leishmania parasites that cause leishmaniasis, which comes second to malaria in terms of parasitic causative fatalities... (Review)
Review
BACKGROUND
Phlebotomine sand flies are prominent vectors of Leishmania parasites that cause leishmaniasis, which comes second to malaria in terms of parasitic causative fatalities globally. In the absence of human vaccines, sand fly chemical-based vector control is a key component of leishmaniasis control efforts.
METHODS AND FINDINGS
We performed a literature review on the current interventions, primarily, insecticide-based used for sand fly control, as well as the global insecticide resistance (IR) status of the main sand fly vector species. Indoor insecticidal interventions, such as residual spraying and treated bed nets are the most widely deployed, while several alternative control strategies are also used in certain settings and/or are under evaluation. IR has been sporadically detected in sand flies in India and other regions, using non-standardized diagnostic bioassays. Molecular studies are limited to monitoring of known pyrethroid resistance mutations (kdr), which are present at high frequencies in certain regions.
CONCLUSIONS
As the leishmaniasis burden remains a major problem at a global scale, evidence-based rational use of insecticidal interventions is required to meet public health demands. Standardized bioassays and molecular markers are a prerequisite for this task, albeit are lagging behind. Experiences from other disease vectors underscore the need for the implementation of appropriate IR management (IRM) programs, in the framework of integrated vector management (IVM). The implementation of alternative strategies seems context- and case-specific, with key eco-epidemiological parameters yet to be investigated. New biotechnology-based control approaches might also come into play in the near future to further reinforce sand fly/leishmaniasis control efforts.
Topics: Animals; Global Health; Humans; Insect Vectors; Insecticide Resistance; Insecticides; Leishmania; Leishmaniasis; Psychodidae
PubMed: 34383751
DOI: 10.1371/journal.pntd.0009586 -
Zoonoses and Public Health Aug 2022Leishmania spp. are sand fly-borne protozoan parasites causing leishmaniasis in humans and animals. The aim of the study was to analyse the epidemiology of leishmaniasis... (Review)
Review
Leishmania spp. are sand fly-borne protozoan parasites causing leishmaniasis in humans and animals. The aim of the study was to analyse the epidemiology of leishmaniasis in Turkey, Azerbaijan and Georgia from 2005 to 2020 and evaluate the associated risk for disease emergence in European countries. It is based on an analysis of WHO and OIE reported cases between 2005 and 2020, a review of scientific articles published in SCOPUS between 2009 and 2020 and a questionnaire survey to public health and veterinary authorities in these countries. Endemic Leishmania spp. include L. infantum in the three countries, L. major in Azerbaijan and Turkey and L. tropica and L. donovani in Turkey. Leishmaniasis is reported in humans, animals and sand flies and incidence is spatially and temporarily variable. In the southern Caucasus and particularly in Georgia, reported incidence of human visceral leishmaniasis by L. infantum remains high. However, whilst Georgia experienced a gradual decrease from >4.0 cases per 100,000 population in 2005-09 to 1.13 cases per 100,000 population in 2020, the period with highest incidence in Azerbaijan, which ranged between 0.40 and 0.61 cases per 100,000 population, was 2016-2019, and no cases have so far been reported for 2020. Visceral leishmaniasis in the Southern Caucasus affects mostly young children from deprived urban areas and its closely associated to canine leishmaniasis. Turkey reported cases of visceral leishmaniasis between 2005 and 2012 and in 2016 only, and incidence ranged between 0.02 and 0.05 per 100,000 population. In contrast, the reported annual incidence of cutaneous leishmaniasis in Turkey was much greater and peaked at 7.02 cases per 100,000 population in 2013, associated to imported cases from cutaneous leishmaniasis endemic Syria. Leishmaniasis by L. infantum in Azerbaijan and Georgia represents a regional public and animal health challenge that requires support to improve diagnosis, treatment and control. The unprecedented rise of cutaneous leishmaniasis and the spread of L. tropica and L. donovani in Turkey is an important risk factor for their emergence in Europe, especially in Mediterranean countries where competent vectors are widespread.
Topics: Animals; Azerbaijan; Dog Diseases; Dogs; Europe; Georgia (Republic); Leishmaniasis, Cutaneous; Leishmaniasis, Visceral; Psychodidae; Turkey
PubMed: 35615899
DOI: 10.1111/zph.12977 -
Acta Tropica Aug 2024This study updates knowledge on historical geographic distribution of sand fly species through identifying altitudinal and bioclimatic patterns in leishmaniasis endemic...
Surveillance of sand flies (Psychodidae, Phlebotominae) from Mexico: Altitudinal and climatic patterns after historical and new geographic records in endemic areas of leishmaniasis.
This study updates knowledge on historical geographic distribution of sand fly species through identifying altitudinal and bioclimatic patterns in leishmaniasis endemic areas in Mexico. We analyze and identify sand fly specimens obtained through national efforts by the Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, Mexico), collected between 1995 and 2001, 2008-2012, and 2017-2023, and add bibliographic information (427 additional records). After a principal components analysis of WorldClim variables and altitudinal ranges, variables that better explain the distribution of sand fly species were chosen (BIO6, BIO12, and BIO16, explaining 72 % of variation). A total of 1,187 specimens of 22 species were retrieved from eight states, providing 29 new municipalities and 48 new localities, being Lutzomyia cruciata, Micropygomyia chiapanensis, and Psathyromyia shannoni the most common species. We presented new historical records of distribution for sand fly species from Morelos (3), Oaxaca (7) and Tabasco (1). The 82.7 % of sand fly species analyzed were distributed in areas with altitudinal ranges below 420 m. The anthropophilic species Psathyromyia shannoni, and Lutzomyia cruciata showed the greatest variability regarding altitudinal range, and climatic preferences, while several wild species showed abiotic preferences. It is likely that the effect of urbanization and climate change generate new beneficial biotopes for the proliferation of the vector sand fly species. Complementary studies that consider seasonality, vegetation types, and change in land use could provide new information to better understand the spread of vector-borne diseases.
Topics: Animals; Mexico; Psychodidae; Leishmaniasis; Altitude; Insect Vectors; Climate; Animal Distribution; Endemic Diseases; Humans; Female; Male
PubMed: 38795873
DOI: 10.1016/j.actatropica.2024.107270 -
Journal of Arthropod-borne Diseases Dec 2022Leishmaniasis is one of the most important vector-borne and neglected tropical diseases in many parts of the world. The main objective of this study was to determine the...
BACKGROUND
Leishmaniasis is one of the most important vector-borne and neglected tropical diseases in many parts of the world. The main objective of this study was to determine the biodiversity of phlebotomine sand flies (Diptera: Psychodidae, Phlebotominae) in Khuzestan and Kermanshah Provinces of Iran.
METHODS
Sampling was conducted in Khuzestan and Kermanshah Provinces using sticky paper traps and CDC light traps. The samples were then stored in 96% alcohol-containing vials, mounted, and identified. Afterward, the alpha diversity (using Simpson's, Shannon-Weiner's diversity, evenness, Maghalef's, Menhinick's, Hill and indices) and beta diversity indices (using Sorensen's and Jaccard's coefficients) were calculated.
RESULTS
A total of 4302 sand flies were caught and identified which comprised mostly of , and . It was found that among the four counties of Ahvaz, Shush, Shushtar and Dezful in Khuzestan Province, Shush had the lowest, and Shushtar, the highest amount of species diversity and evenness. In the four studied counties of Kermanshah Province, species diversity in Kermanshah County had the lowest amount and Sarpol-e-Zahab, the highest. The species richness in Kermanshah County was the lowest, while Qasr-e-Shirin County had the highest amount.
CONCLUSION
An overview of the biodiversity of phlebotomine sand flies in Kermanshah County in Kermanshah Province, and Shush County in Khuzestan Province, showed less stability in community structure of these vectors, which can be counted as an alarm for emerging dominant vectors among the studied counties and have the potential to increase the prevalence of leishmaniasis.
PubMed: 37159595
DOI: 10.18502/jad.v16i4.12189 -
ZooKeys 2022Phlebotomine sand flies (Diptera: Psychodidae) are the natural vectors of spp. (Kinetoplastida: Trypanosomatidae) and phleboviruses (Bunyavirales: Phenuiviridae). In...
Phlebotomine sand flies (Diptera: Psychodidae) are the natural vectors of spp. (Kinetoplastida: Trypanosomatidae) and phleboviruses (Bunyavirales: Phenuiviridae). In Spain, these vectors appear to be increasing their geographical distribution and have serious repercussions on public and veterinary health, encouraging studies of sand flies and their associated pathogens. An up-to-date and easily accessible compendium of current and historical data on their presence and detailed distribution is a crucial step towards the development and implementation of appropriate preventive strategies. A checklist on the presence and distribution of sand flies in Spain is compiled from data extracted from a comprehensive review of scientific literature published between 1909 and 2021 and our new records on the presence of sand flies specimens collected under the entomological surveillance of bluetongue vectors from the Spanish Ministry of Agriculture, Fishery and Food (MAPA) during the period 2004-2021. In total, 13 Spanish species of sand flies (two of them with controversial status) belonging to two genera and six subgenera are presented in this updated checklist, including new distribution data for seven species, among which several stand out as confirmed or suspected vectors of : , , , .
PubMed: 36760819
DOI: 10.3897/zookeys.1106.81432 -
Memorias Do Instituto Oswaldo Cruz 2021Leishmaniases are diseases transmitted by some species of sand flies and are widely distributed throughout the tropical regions of the planet. Despite the low mobility...
BACKGROUND
Leishmaniases are diseases transmitted by some species of sand flies and are widely distributed throughout the tropical regions of the planet. Despite the low mobility of these vectors, the geographical distributions of some species are quite extensive, which hinders control and surveillance measures in endemic areas.
OBJECTIVES
The present study investigated the flying capacity of sand flies.
METHODS
Four Hoover Penido (HP)-type light traps were positioned in the centre of the Velhas' River, about 80 metres equidistant from each other. We also realised capture/release/recapture attempts to assess possible capacity of phlebotomine fly uninterrupted up to 150 metres. Captured sand flies from one side of the river were marked using fluorescent powder (Luminous Paint kit, Bioquip®) and released on the other side, approximately 150 m distant. Recapture attempts were made on river's bank up to 30 days post-release.
FINDINGS
Six sand flies of the species Nyssomyia neivai (n = 4), Ny. intermedia (n = 1) and Evandromyia lenti (n = 1) were captured in the centre of the river. There were no recaptures of the 1,450 marked-and-released sand flies.
MAIN CONCLUSIONS
The results obtained disagree with data found in the literature regarding the flight capacity of sand fly vectors of leishmaniasis.
Topics: Animals; Insect Vectors; Leishmaniasis; Phlebotomus; Psychodidae
PubMed: 34816885
DOI: 10.1590/0074-02760210230 -
Frontiers in Cellular and Infection... 2022Sand flies are hematophagous insects responsible for the transmission of vector-borne diseases to humans. Prominent among these diseases is Leishmaniasis that affects... (Review)
Review
Sand flies are hematophagous insects responsible for the transmission of vector-borne diseases to humans. Prominent among these diseases is Leishmaniasis that affects the skin and mucous surfaces and organs such as liver and spleen. Importantly, the function of blood-sucking arthropods goes beyond merely transporting pathogens. The saliva of vectors of disease contains pharmacologically active components that facilitate blood feeding and often pathogen establishment. Transcriptomic and proteomic studies have enumerated the repertoire of sand fly salivary proteins and their potential use for the control of Leishmaniasis, either as biomarkers of vector exposure or as anti- vaccines. However, a group of specific sand fly salivary proteins triggers formation of cross-reactive antibodies that bind the ectodomain of human desmoglein 1, a member of the epidermal desmosomal cadherins. These cross-reactive antibodies are associated with skin autoimmune blistering diseases, such as pemphigus, in certain immunogenetically predisposed individuals. In this review, we focus on two different aspects of sand fly salivary proteins in the context of human disease: The good, which refers to salivary proteins functioning as biomarkers of exposure or as anti- vaccines, and the bad, which refers to salivary proteins as environmental triggers of autoimmune skin diseases.
Topics: Animals; Autoimmunity; Leishmaniasis; Proteomics; Psychodidae; Salivary Proteins and Peptides
PubMed: 35281450
DOI: 10.3389/fcimb.2022.839932 -
Virulence Dec 2021Catalase is one of the most abundant enzymes on Earth. It decomposes hydrogen peroxide, thus protecting cells from dangerous reactive oxygen species. The...
Catalase 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. Here, we expressed this protein from the locus using a novel bicistronic expression system, which relies on the 2A peptide of . We demonstrated that catalase-expressing parasites are severely compromised in their ability to develop in insects, to be transmitted and to infect mice, and to cause clinical manifestation in their mammalian host. Taken together, our data support the hypothesis that the presence of catalase is not compatible with the dixenous life cycle of , resulting in loss of this gene from the genome during the evolution of these parasites.
Topics: Animals; Catalase; Cells, Cultured; Female; Leishmania mexicana; Life Cycle Stages; Mice; Mice, Inbred BALB C; Protozoan Proteins; Psychodidae; Teschovirus; Virulence; Virulence Factors
PubMed: 33724149
DOI: 10.1080/21505594.2021.1896830 -
Frontiers in Cellular and Infection... 2021In the lifecycle, the motile promastigote form is transmitted from the sand fly vector to a mammalian host during a blood meal. Inside vertebrate host macrophages, the... (Review)
Review
In the lifecycle, the motile promastigote form is transmitted from the sand fly vector to a mammalian host during a blood meal. Inside vertebrate host macrophages, the parasites can differentiate into the amastigote form and multiply, causing leishmaniasis, one of the most significant neglected tropical diseases. parasites face different conditions throughout their development inside sand flies. Once in the mammalian host, the parasites have to overcome the microbicide repertoire of the cells of the immune system to successfully establish the infection. In this context, the expression of protein phosphatases is of particular interest. Several members of the serine/threonine-specific protein phosphatase (STP), protein tyrosine phosphatase (PTP), and histidine acid phosphatase (HAcP) families have been described in different species. Although their physiological roles have not been fully elucidated, many studies suggest they have an involvement with parasite biology and pathogeny. Phosphatases play a role in adaptation to nutrient starvation during parasite passage through the sand fly midgut. They are also important to parasite virulence, mainly due to the modulation of host cytokine production and impairment of the microbiocidal potential of macrophages. Furthermore, recent whole-genome expression analyses have shown that different phosphatases are upregulated in metacyclic promastigotes, the infective form of the mammalian host. phosphatases are also upregulated in drug-resistant strains, probably due to the increase in drug efflux related to the activation of ABC transporters. Throughout this review, we will describe the physiological roles that have been attributed to endogenous phosphatases, including their involvement in the adaptation, survival, and proliferation of the parasites inside their hosts.
Topics: Animals; Biology; Leishmania; Parasites; Phosphoric Monoester Hydrolases; Psychodidae
PubMed: 33968798
DOI: 10.3389/fcimb.2021.633146