scholarly journals The Phlebotomus papatasi transcriptomic response to trypanosomatid-contaminated blood is robust but non-specific

2019 ◽  
Author(s):  
Megan A. Sloan ◽  
Jovana Sadlova ◽  
Tereza Lestinova ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  
Keyword(s):  
Blood Meal ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Blood Feeding ◽  
Sand Fly ◽  
Insect Vector ◽  
Sand Flies ◽  
Phlebotomus Papatasi ◽  
Transcriptomic Response ◽  
Gene Expression Response

AbstractLeishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the fly. In this work we wanted to identify fly transcriptomic signatures associated with infection success or failure. We used next generation sequencing to describe the transcriptome of the sand fly Phlebotomus papatasi when fed with blood alone or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans. Of these, only L. major was able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed were not specific to success or failure of infection but a generalised response to the blood meal. This implies that sand flies perceive Leishmania as just a feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment.Authors summaryLeishmania are parasites that cause leishmaniasis, a group of serious diseases that affect millions of people, mainly across the subtropics and tropics. They are transmitted to humans by phlebotomine sand flies. However, despite establishment in the insect’s midgut being key to transmission, early infection events inside the insect are still unclear. Here, we study the gene expression response of the insect vector to a Leishmania parasite that is able to establish infection (L. major) one that is unable to do so (L. donovani) as well as one that is not a natural parasite of sand flies (Herpetomonas muscarum). We found that responses following any of the infected blood meals was very similar to uninfected blood meal. However, changes post-blood meal from day 1 to day 9 were dramatic. As a blood feeding insect can accumulate three times its weight in one blood meal, this seems to be the most important physiological change rather than the presence of the parasite. The latter might be just one in a number of microbes the insect encounters. This result will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

scholarly journals The Phlebotomus Papatasi Transcriptomic Response to Trypanosomatid-contaminated Blood is Robust but non-specific

2020 ◽  
Author(s):  
Megan A. Sloan ◽  
Jovana Sadlova ◽  
Tereza Lestinova ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  
Keyword(s):  
Blood Meal ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Sand Fly ◽  
Phlebotomus Papatasi ◽  
Transcriptomic Response ◽  
Infected Blood ◽  
New Thinking ◽  
Contaminated Blood ◽  
Generation Sequencing

Abstract Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the fly.Methods In this work we wanted to identify fly transcriptomic signatures associated with infected blood meal with non-infected blood meal as our baseline. We used next generation sequencing to describe the transcriptome of the sand fly Phlebotomus papatasi when fed with blood alone or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans.Results Of these, only L. major was able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed were not specific to success or failure of infection but a generalised response to the blood meal.Conclusions This implies that sand flies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. This result will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

scholarly journals The Phlebotomus papatasi systemic transcriptional response to trypanosomatid-contaminated blood does not differ from the non-infected blood meal

2020 ◽  
Author(s):  
Megan A. Sloan ◽  
Jovana Sadlova ◽  
Tereza Lestinova ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  
Keyword(s):  
Blood Meal ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Transcriptional Response ◽  
Sand Fly ◽  
Host Responses ◽  
Sand Flies ◽  
Phlebotomus Papatasi ◽  
New Thinking ◽  
Contaminated Blood

Abstract Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the fly. Methods In this work we wanted to identify fly systemic transcriptomic signatures associated with Leishmania infection. We used next generation sequencing to describe the transcriptome of whole Phlebotomus papatasi sand flies when fed with blood alone (control) or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans. Results Of these, only L. major is able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed after each parasite-contaminated blood meal were not specific to success or failure of a specific infection and were not different from each other. They were also indistinguishable from non-contaminated blood. Conclusions This implies that sand flies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. Alternatively, Leishmania could suppress host responses. These results will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

scholarly journals The Phlebotomus papatasi systemic transcriptional response to trypanosomatid-contaminated blood does not differ from the non-infected blood meal

2020 ◽  
Author(s):  
Megan A. Sloan ◽  
Jovana Sadlova ◽  
Tereza Lestinova ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  
Keyword(s):  
Blood Meal ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Transcriptional Response ◽  
Sand Fly ◽  
Host Responses ◽  
Sand Flies ◽  
Phlebotomus Papatasi ◽  
New Thinking ◽  
Contaminated Blood

Abstract Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that effects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control, require a better understanding of the key step for transmission namely, the establishment of infection inside the fly. Methods In this work we wanted to identify fly systemic transcriptomic signatures associated with Leishmania infection. We used next generation sequencing to describe the transcriptome of whole Phlebotomus papatasi sand flies when fed with blood alone (control) or with blood containing one of three trypanosomatids: Leishmania major, Leishmania donovani and Herpetomonas muscarum: a parasite not transmitted to humans. Results Of these, only L. major is able to successfully establish an infection in P. papatasi. However, the transcriptional signatures observed after each parasite-contaminated blood meal were not specific to success or failure of a specific infection and were not different from each other. They were also indistinguishable from non-contaminated blood. Conclusions This implies that sand flies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. Alternatively, Leishmania could suppress host responses. These results will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

scholarly journals Molecular detection of Leishmania donovani, Leishmania major, and Trypanosoma species in Sergentomyia squamipleuris sand flies from a visceral leishmaniasis focus in Merti sub-County, eastern Kenya

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Barrack O. Owino ◽  
Jackline Milkah Mwangi ◽  
Steve Kiplagat ◽  
Hannah Njiriku Mwangi ◽  
Johnstone M. Ingonga ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Mus Musculus ◽  
Blood Meal ◽  
Leishmania Donovani ◽  
Leishmania Major ◽  
Sand Fly ◽  
Health Concern ◽  
Sand Flies ◽  
Reservoir Hosts ◽  
Blood Meals

Abstract Background Visceral leishmaniasis (VL) and zoonotic cutaneous leishmaniasis (ZCL) are of public health concern in Merti sub-County, Kenya, but epidemiological data on transmission, vector abundance, distribution, and reservoir hosts remain limited. To better understand the disease and inform control measures to reduce transmission, we investigated the abundance and distribution of sand fly species responsible for Leishmania transmission in the sub-County and their blood-meal hosts. Methods We conducted an entomological survey in five villages with reported cases of VL in Merti sub-County, Kenya, using CDC miniature light traps and castor oil sticky papers. Sand flies were dissected and identified to the species level using standard taxonomic keys and PCR analysis of the cytochrome c oxidase subunit 1 (cox1) gene. Leishmania parasites were detected and identified by PCR and sequencing of internal transcribed spacer 1 (ITS1) genes. Blood-meal sources of engorged females were identified by high-resolution melting analysis of vertebrate cytochrome b (cyt-b) gene PCR products. Results We sampled 526 sand flies consisting of 8 species, Phlebotomus orientalis (1.52%; n = 8), and 7 Sergentomyia spp. Sergentomyia squamipleuris was the most abundant sand fly species (78.71%; n = 414) followed by Sergentomyia clydei (10.46%; n = 55). Leishmania major, Leishmania donovani, and Trypanosoma DNA were detected in S. squamipleuris specimens. Humans were the main sources of sand fly blood meals. However, we also detected mixed blood meals; one S. squamipleuris specimen had fed on both human and mouse (Mus musculus) blood, while two Ph. orientalis specimens fed on human, hyrax (Procavia capensis), and mouse (Mus musculus) blood. Conclusions Our findings implicate the potential involvement of S. squamipleuris in the transmission of Leishmania and question the dogma that human leishmaniases in the Old World are exclusively transmitted by sand flies of the Phlebotomus genus. The presence of Trypanosoma spp. may indicate mechanical transmission, whose efficiency should be investigated. Host preference analysis revealed the possibility of zoonotic transmission of leishmaniasis and other pathogens in the sub-County. Leishmania major and L. donovani are known to cause ZCL and VL, respectively. However, the reservoir status of the parasites is not uniform. Further studies are needed to determine the reservoir hosts of Leishmania spp. in the area.

scholarly journals The Phlebotomus papatasi systemic transcriptional response to trypanosomatid-contaminated blood does not differ from the non-infected blood meal

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Megan A. Sloan ◽  
Jovana Sadlova ◽  
Tereza Lestinova ◽  
Mandy J. Sanders ◽  
James A. Cotton ◽  
...  
Keyword(s):  
Blood Meal ◽  
Leishmania Major ◽  
Transcriptional Response ◽  
Sand Fly ◽  
Host Responses ◽  
Sand Flies ◽  
Phlebotomus Papatasi ◽  
Infected Blood ◽  
New Thinking ◽  
Contaminated Blood

Abstract Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that affects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control require a better understanding of the key step for transmission, namely the establishment of infection inside the fly. Methods The aim of this work was to identify sand fly systemic transcriptomic signatures associated with Leishmania infection. We used next generation sequencing to describe the transcriptome of whole Phlebotomus papatasi sand flies when fed with blood alone (control) or with blood containing one of three trypanosomatids: Leishmania major, L. donovani and Herpetomonas muscarum, the latter being a parasite not transmitted to humans. Results Of the trypanosomatids studied, only L. major was able to successfully establish an infection in the host P. papatasi. However, the transcriptional signatures observed after each parasite-contaminated blood meal were not specific to success or failure of a specific infection and they did not differ from each other. The transcriptional signatures were also indistinguishable after a non-contaminated blood meal. Conclusions The results imply that sand flies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. Alternatively, Leishmania could suppress host responses. These results will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.

scholarly journals CRISPR/Cas9 Mutagenesis in Phlebotomus papatasi: the Immune Deficiency Pathway Impacts Vector Competence for Leishmania major

mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Isabelle Louradour ◽  
Kashinath Ghosh ◽  
Ehud Inbar ◽  
David L. Sacks
Keyword(s):  
Immune Deficiency ◽  
Immune Response ◽  
Leishmania Major ◽  
Vector Competence ◽  
Targeted Mutagenesis ◽  
Sand Fly ◽  
Sand Flies ◽  
Phlebotomus Papatasi ◽  
Content Type ◽  
Imd Pathway

ABSTRACT Sand flies are the natural vectors for the Leishmania species that produce a spectrum of diseases in their mammalian hosts, including humans. Studies of sand fly/Leishmania interactions have been limited by the absence of genome editing techniques applicable to these insects. In this report, we adapted CRISPR (clustered regularly interspaced palindromic repeat)/Cas9 (CRISPR-associated protein 9) technology to the Phlebotomus papatasi sand fly, a natural vector for Leishmania major, targeting the sand fly immune deficiency (IMD) pathway in order to decipher its contribution to vector competence. We established a protocol for transformation in P. papatasi and were able to generate transmissible null mutant alleles for Relish (Rel), the only transcription factor of the IMD pathway. While the maintenance of a homozygous mutant stock was severely compromised, we were able to establish in an early generation their greater susceptibility to infection with L. major. Flies carrying different heterozygous mutant alleles variably displayed a more permissive phenotype, presenting higher loads of parasites or greater numbers of infective-stage promastigotes. Together, our data show (i) the successful adaptation of the CRISPR/Cas9 technology to sand flies and (ii) the impact of the sand fly immune response on vector competence for Leishmania parasites. IMPORTANCE Sand flies are the natural vectors of Leishmania parasites. Studies of sand fly/Leishmania interactions have been limited by the lack of successful genomic manipulation of these insects. This paper shows the first example of successful targeted mutagenesis in sand flies via adaptation of the CRISPR/Cas9 editing technique. We generated transmissible null mutant alleles of relish, a gene known to be essential for the control of immune response in other insects. In addition to the expected higher level of susceptibility to bacteria, the mutant flies presented higher loads of parasites when infected with L. major, showing that the sand fly immune response impacts its vector competence for this pathogen.

scholarly journals Response to thermal and infection stresses in an American vector of visceral leishmaniasis

2020 ◽  
Author(s):  
Kelsilandia A. Martins ◽  
Caroline S. Morais ◽  
Susan J. Broughton ◽  
Claudio R. Lazzari ◽  
Paul A. Bates ◽  
...  
Keyword(s):  
Heat Shock ◽  
Body Temperature ◽  
Visceral Leishmaniasis ◽  
Heat Shock Proteins ◽  
Blood Meal ◽  
Blood Feeding ◽  
The Body ◽  
Sand Fly ◽  
Sand Flies ◽  
Shock Proteins

AbstractThe phlebotomine sand fly Lutzomyia longipalpis is the primary insect vector of visceral leishmaniasis in the Americas. For ectothermic organisms such as sand flies, the ambient temperature is a critical factor influencing all aspects of their life. However, the impact of temperature has been ignored in previous investigations of stress-induced responses by the vector, such as taking a blood meal or during Leishmania infection. Therefore, this study explored the interaction of Lu. longipalpis with temperature by evaluating sand fly behaviour across a thermal gradient after sugar or blood-feeding, and infection with Leishmania mexicana. Thermographic recordings of sand fly females fed on mice were analysed, and the gene expression of heat shock proteins HSP70 and HSP90(83) was evaluated when insects were exposed to extreme temperatures or infected. The results showed that 72h after blood ingestion females of Lu. longipalpis became less active and preferred relatively low temperatures. However, at later stages of blood digestion females increased their activity and remained at higher temperatures prior to taking a second blood meal; this behaviour seems to be correlated with the evolution of their oocysts and voracity for a second blood meal. No changes in the temperature preferences of female sand flies were recorded in the presence of a gut infection by Le. mexicana, indicating that this parasite has not triggered behavioural immunity in Lu. longipalpis. Real-time imaging showed that the body temperature of female flies feeding on mice increased to the same temperature as the host within a few seconds after landing. The body temperature of females remained around 35 ± 0.5 °C until the end of blood-feeding, revealing a lack of thermoregulatory behaviour. Analysis of expression of heat shock proteins revealed insects increased expression of HSP90(83) when exposed to higher temperatures, such as during blood feeding. Our findings suggest that Lu. longipalpis interacts with the environmental temperature by using its behaviour to avoid temperature-related physiological damage during the gonotrophic cycle. However, the expression of certain heat shock proteins might be triggered to mitigate against thermal stress in situations where a behavioural response is not the best option.

scholarly journals Micro-CT visualization of a promastigote secretory gel (PSG) and parasite plug in the digestive tract of the sand fly Lutzomyia longipalpis infected with Leishmania mexicana

2021 ◽  
Vol 15 (8) ◽  
pp. e0009682
Author(s):  
Martin J. R. Hall ◽  
Debashis Ghosh ◽  
Daniel Martín-Vega ◽  
Brett Clark ◽  
Innes Clatworthy ◽  
...  
Keyword(s):  
Blood Meal ◽  
Blood Feeding ◽  
Sand Fly ◽  
Laboratory Model ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Leishmania Mexicana ◽  
Micro Computed Tomography ◽  
The Tropics ◽  
The Impact

Leishmaniasis is a debilitating disease of the tropics, subtropics and southern Europe caused by Leishmania parasites that are transmitted during blood feeding by phlebotomine sand flies (Diptera: Psychodidae). Using non-invasive micro-computed tomography, we were able to visualize the impact of the laboratory model infection of Lutzomyia longipalpis with Leishmania mexicana and its response to a second blood meal. For the first time we were able to show in 3D the plug of promastigote secretory gel (PSG) and parasites in the distended midgut of whole infected sand flies and measure its volume in relation to that of the midgut. We were also able to measure the degree of opening of the stomodeal valve and demonstrate the extension of the PSG and parasites into the pharynx. Although our pilot study could only examine a few flies, it supports the hypothesis that a second, non-infected, blood meal enhances parasite transmission as we showed that the thoracic PSG-parasite plug in infected flies after a second blood meal was, on average, more than twice the volume of the plug in infected flies that did not have a second blood meal.

scholarly journals Estimation of vector competence of Moroccan Sand fly Populations Using a Proteomic Approach

2020 ◽  
Author(s):  
Mohamed Daoudi ◽  
George Dong ◽  
Samia Boussaa ◽  
Caroline Martel ◽  
Mohamed Hafidi ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Leishmania Major ◽  
Vector Competence ◽  
Sand Fly ◽  
Sand Flies ◽  
Phlebotomus Papatasi ◽  
Chromatography Tandem Mass Spectrometry ◽  
Proteomic Approach ◽  
Liquid Chromatography Tandem Mass ◽  
Leishmania Spp

Abstract Background Phlebotomine vector born disease are distributed throughout the world, and different pathogens are associated with varying degrees of disease severity. In Morocco, sand fly populations are incriminated in the transmission of several pathogens, such Leishmania spp. and phlebovirus, in particular the most relevant sand fly species as the case of Phlebotomus papatasi. This species is the main vector of Leishmania major in Morocco, and incriminated in phlebovirus transmission. Not to pass over without investigating its possible role on the transmission of entomopathogenic parasite already reported in literature. Methodology and finding The present study focused on proteomic analysis in Phlebotomus papatasi from four localities in Morocco. Proteomic analysis in female P. papatasi was performed with Liquid chromatography-tandem mass spectrometry (LC-MS/MS). A total of 239 identified proteins for Leishmania spp., 26 identified proteins for phlebovirus and 1132 identified proteins for nematode were detected in the 20 pools of P. papatasi from investigated localities. The microscopic examination of 1752 sandflies collected showed, the infection of two specimens of female’s P. sergenti with Tetranematid Didilia spp. and potential Microfilariae in Imintanout locality (Z2).Conclusion This study presents the first report of nematodes in sand flies of Africa. Also, the first use of proteomic tools for estimation of vector competence of P. papatasi which could be a specific tool to a better understanding of the vectorial capacity of Moroccan sandflies population.

A novel role for the peritrophic matrix in protecting Leishmania from the hydrolytic activities of the sand fly midgut

Parasitology ◽  
1997 ◽  
Vol 115 (4) ◽  
pp. 359-369 ◽  
Author(s):  
P. F. P. PIMENTA ◽  
G. B. MODI ◽  
S. T. PEREIRA ◽  
M. SHAHABUDDIN ◽  
D. L. SACKS
Keyword(s):  
Digestive Enzymes ◽  
Leishmania Major ◽  
Specific Inhibitor ◽  
Sand Fly ◽  
Peritrophic Matrix ◽  
Phlebotomus Papatasi ◽  
Hydrolytic Activities ◽  
Natural Vector ◽  
Parasite Survival

The role of the peritrophic matrix (PM) in the development of Leishmania major infections in a natural vector, Phlebotomus papatasi, was investigated by addition of exogenous chitinase to the bloodmeal, which completely blocked PM formation. Surprisingly, the absence of the PM was associated with the loss of midgut infections. The chitinase was not directly toxic to the parasite, nor were midgut infections lost due to premature expulsion of the bloodmeal. Most parasites were killed in chitinase-treated flies within the first 4 h after feeding. Substantial early killing was also observed in control flies, suggesting that the lack of PM exacerbates lethal conditions which normally exist in the blood-fed midgut. Early parasite mortality was reversed by soybean trypsin inhibitor. Allosamadin, a specific inhibitor of chitinase, led to a thickening of the PM, and also prevented the early parasite mortality seen in infected flies. Susceptibility to gut proteases was extremely high in transitional-stage parasites, while amastigotes and fully transformed promastigotes were relatively resistant. A novel role for the PM in promoting parasite survival is suggested, in which the PM creates a barrier to the rapid diffusion of digestive enzymes, and limits the exposure of parasites to these enzymes during the time when they are especially vulnerable to proteolytic damage.

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