Response to Blood Meal in the Fat Body of Anopheles stephensi Using Quantitative Proteomics: Toward New Vector Control Strategies Against Malaria

Female mosquitoes require a blood meal for reproduction, and this blood meal provides the underlying mechanism for the spread of many important vector-borne diseases in humans. A deeper understanding of the molecular mechanisms linked to mosquito blood meal processes and reproductive events is of particular importance for devising innovative vector control strategies. We found that the conserved microRNA miR-8 is an essential regulator of mosquito reproductive events. Two strategies to inhibit miR-8 function in vivo were used for functional characterization: systemic antagomir depletion and spatiotemporal inhibition using the miRNA sponge transgenic method in combination with the yeast transcriptional activator gal4 protein/upstream activating sequence system. Depletion of miR-8 in the female mosquito results in defects related to egg development and deposition. We used a multialgorithm approach for miRNA target prediction in mosquito 3′ UTRs and experimentally verified secreted wingless-interacting molecule (swim) as an authentic target of miR-8. Our findings demonstrate that miR-8 controls the activity of the long-range Wingless (Wg) signaling by regulating Swim expression in the female fat body. We discovered that the miR-8/Wg axis is critical for the proper secretion of lipophorin and vitellogenin by the fat body and subsequent accumulation of these yolk protein precursors by developing oocytes.

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Contemporary Resistance Status of Anopheles Stephensi against Insecticides in District Dungarpur, Rajasthan, India

JOURNAL OF COMMUNICABLE DISEASES ◽

10.24321/0019.5138.202151 ◽

2021 ◽

Vol 53 (03) ◽

pp. 153-158

Author(s):

Sarmad Moin ◽

Keyword(s):

Vector Control ◽

Standard Method ◽

Anopheles Stephensi ◽

Control Strategies ◽

Control Program ◽

Sensitivity Study ◽

Entire Study ◽

Vector Control Program ◽

Susceptibility Study ◽

Ecological Methods

Pyrethroids are powerful insecticides used in the vector control program with impregnated mesh, and residual indoor sprays. However, resistance to insecticide reduces the effectiveness. The present susceptibility study carried out against theAnopheles Stephensi to monitor the sensitivity conditions of An. Stephensi vector, which raises the need to understand the state of vector resistance in the Dungarpur region of Rajasthan, India in order to better report vector-based interventions. The sensitivity study was carried out by the WHO standard method using recommended diagnostic doses of DDT, alpha-cypermethrin, permethrin, and deltamethrin. An. Stephensi showed resistance to DDT from the entire study while sensitive to alpha-cypermethrin, permethrin, and deltamethrin. The study looks at the selection and circulation of the appropriate insecticide’s molecule for a vector control program as insecticide need constant monitoring to develop effective vector control strategies such as improving insecticide by applying integrated biological and ecological methods.

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Fat and Happy: Profiling Mosquito Fat Body Lipid Storage and Composition Post-blood Meal

Frontiers in Insect Science ◽

10.3389/finsc.2021.693168 ◽

2021 ◽

Vol 1 ◽

Author(s):

Matthew Pinch ◽

Soumi Mitra ◽

Stacy D. Rodriguez ◽

Yiyi Li ◽

Yashoda Kandel ◽

...

Keyword(s):

Lipid Composition ◽

Blood Meal ◽

Lipid Droplets ◽

Mosquito Control ◽

Fat Body ◽

Control Strategies ◽

Fat Tissue ◽

Body Lipid ◽

Yolk Formation ◽

Dynamic Changes

The fat body is considered the insect analog of vertebrate liver and fat tissue. In mosquitoes, a blood meal triggers a series of processes in the fat body that culminate in vitellogenesis, the process of yolk formation. Lipids are stored in the fat body in specialized organelles called lipid droplets that change in size depending on the nutritional and metabolic status of the insect. We surveyed lipid droplets in female Aedes aegypti fat body during a reproductive cycle using confocal microscopy and analyzed the dynamic changes in the fat body lipidome during this process using LC/MS. We found that lipid droplets underwent dynamic changes in volume after the mosquito took a blood meal. The lipid composition found in the fat body is quite complex with 117 distinct lipids that fall into 19 classes and sublcasses. Our results demonstrate that the lipid composition of the fat body is complex as most lipid classes underwent significant changes over the course of the vitellogenic cycle. This study lays the foundation for identifying unknown biochemical pathways active in the mosquito fat body, that are high-value targets for the development of novel mosquito control strategies.

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High insecticide resistance mediated by different mechanisms in Culex quinquefasciatus populations from the city of Yaoundé, Cameroon

Scientific Reports ◽

10.1038/s41598-021-86850-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Abdou Talipouo ◽

Konstantinos Mavridis ◽

Elysée Nchoutpouen ◽

Borel Djiappi-Tchamen ◽

Emmanouil Alexandros Fotakis ◽

...

Keyword(s):

Insecticide Resistance ◽

Vector Control ◽

High Resistance ◽

Culex Quinquefasciatus ◽

Control Strategies ◽

Cuticular Hydrocarbon ◽

Control Measures ◽

High Frequencies ◽

The City ◽

Integrated Vector Control

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.

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Predicting Aedes aegypti infestation using landscape and thermal features

Scientific Reports ◽

10.1038/s41598-020-78755-8 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Camila Lorenz ◽

Marcia C. Castro ◽

Patricia M. P. Trindade ◽

Maurício L. Nogueira ◽

Mariana de Oliveira Lage ◽

...

Keyword(s):

Remote Sensing ◽

Aedes Aegypti ◽

Vector Control ◽

Land Surface ◽

Urban Areas ◽

Negative Binomial ◽

Control Strategies ◽

Winter Season ◽

Landsat 8 ◽

Thermal Features

AbstractIdentifying Aedes aegypti breeding hotspots in urban areas is crucial for the design of effective vector control strategies. Remote sensing techniques offer valuable tools for mapping habitat suitability. In this study, we evaluated the association between urban landscape, thermal features, and mosquito infestations. Entomological surveys were conducted between 2016 and 2019 in Vila Toninho, a neighborhood of São José do Rio Preto, São Paulo, Brazil, in which the numbers of adult female Ae. aegypti were recorded monthly and grouped by season for three years. We used data from 2016 to 2018 to build the model and data from summer of 2019 to validate it. WorldView-3 satellite images were used to extract land cover classes, and land surface temperature data were obtained using the Landsat-8 Thermal Infrared Sensor (TIRS). A multilevel negative binomial model was fitted to the data, which showed that the winter season has the greatest influence on decreases in mosquito abundance. Green areas and pavements were negatively associated, and a higher cover of asbestos roofs and exposed soil was positively associated with the presence of adult females. These features are related to socio-economic factors but also provide favorable breeding conditions for mosquitos. The application of remote sensing technologies has significant potential for optimizing vector control strategies, future mosquito suppression, and outbreak prediction.

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The Fat Body Transcriptomes of the Yellow Fever Mosquito Aedes aegypti, Pre- and Post- Blood Meal

PLoS ONE ◽

10.1371/journal.pone.0022573 ◽

2011 ◽

Vol 6 (7) ◽

pp. e22573 ◽

Cited By ~ 47

Author(s):

David P. Price ◽

Vijayaraj Nagarajan ◽

Alexander Churbanov ◽

Peter Houde ◽

Brook Milligan ◽

...

Keyword(s):

Aedes Aegypti ◽

Yellow Fever ◽

Blood Meal ◽

Fat Body ◽

Yellow Fever Mosquito

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Residual and Fumigant Effects of Bendiocarb WP80 in a Malarious Areas in Borderline of Iran and Pakistan

10.21203/rs.3.rs-139001/v1 ◽

2021 ◽

Author(s):

Mohammad Reza Abai ◽

Hassan Vatandoost ◽

Hossein Dorzadeh ◽

Mansoreh Shayeghi ◽

Ahmad Ali Hanafi-bojd ◽

...

Keyword(s):

Vector Control ◽

Anopheles Stephensi ◽

Indoor Residual Spraying ◽

Residual Effect ◽

Malaria Vector Control ◽

Biological Assays ◽

The Public ◽

Main Activity ◽

Contact Bioassay ◽

Old Females

Abstract Background: Malaria and leishmaniasis are the public health problems in southern Iran. The main activity of vector control is indoor residual spraying using pyrethrpids. The aim of study was to evaluate the biological assays of bendiocarb WP at different surfaces of wall. Materials and Methods: The residual effect of bendicocarb WP80 at 400 mg/m2 was evauated on various local surfaces of rooms such as mud and plaster as well as thatch roofs and wooden. WHO standard cones using contact bioassays were carried out using laboratory reared sugar-fed, 48-72 h old females of Anopheles stephensi . Contact bioassays were carried out on sprayed surfaces for 150 days.Results: Contact bioassay on surfaces treated with bendicocarb WP80 diffferent surfaces was estimated about 2 months. Fumigant tests of bendicocarb WP80 at 400 mg/m2 revealed 50-93.83% mortality with one month persistency.Discussion: The rsults hsowed that carbamte insecticide could be used as rotation with pyrethroids for malaria vector control .

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Optimal Control of a Dengue-Dengvaxia Model: Comparison Between Vaccination and Vector Control

Computational and Mathematical Biophysics ◽

10.1515/cmb-2020-0124 ◽

2021 ◽

Vol 9 (1) ◽

pp. 198-212

Author(s):

Cheryl Q. Mentuda

Keyword(s):

Optimal Control ◽

Vector Control ◽

Basic Reproduction Number ◽

Human Population ◽

Model Comparison ◽

Reproduction Number ◽

Control Strategies ◽

Minimum Principle ◽

Transmitted Disease ◽

The Basic Reproduction Number

Abstract Dengue is the most common mosquito-borne viral infection transmitted disease. It is due to the four types of viruses (DENV-1, DENV-2, DENV-3, DENV-4), which transmit through the bite of infected Aedes aegypti and Aedes albopictus female mosquitoes during the daytime. The first globally commercialized vaccine is Dengvaxia, also known as the CYD-TDV vaccine, manufactured by Sanofi Pasteur. This paper presents a Ross-type epidemic model to describe the vaccine interaction between humans and mosquitoes using an entomological mosquito growth population and constant human population. After establishing the basic reproduction number ℛ0, we present three control strategies: vaccination, vector control, and the combination of vaccination and vector control. We use Pontryagin’s minimum principle to characterize optimal control and apply numerical simulations to determine which strategies best suit each compartment. Results show that vector control requires shorter time applications in minimizing mosquito populations. Whereas vaccinating the primary susceptible human population requires a shorter time compared to the secondary susceptible human.

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Public health response and lessons learned from the 2014 chikungunya epidemic in Grenada

Revista Panamericana de Salud Pública ◽

10.26633/rpsp.2017.57 ◽

2017 ◽

Vol 41 ◽

pp. 1 ◽

Cited By ~ 3

Author(s):

Martin S Forde ◽

Francis Martin ◽

George Mitchell ◽

Satesh Bidaisee

Keyword(s):

Health Care ◽

Vector Control ◽

Control Strategies ◽

Lessons Learned ◽

Epidemiological Surveillance ◽

Mosquito Vector ◽

Public Health Response ◽

Island State ◽

Health Response ◽

Multiple Challenges

In June 2014, the first cases of chikungunya virus (CHIKV) were diagnosed on the island of Carriacou, part of the tri-island state of Grenada. In the three months that followed, CHIKV spread rapidly, with conservative estimates of the population infected of at least 60%. Multiple challenges were encountered in the battle to manage the spread and impact of this high–attack rate virus, including 1) limited indigenous laboratory diagnostic capabilities; 2) an under-resourced health care system; 3) a skeptical general public, hesitant to accept facts about the origin and mode of transmission of the new virus; and 4) resistance to the vector control strategies used. Lessons learned from the outbreak included the need for 1) a robust and reliable epidemiological surveillance system; 2) effective strategies for communicating with the general population; 3) exploration of other methods of mosquito vector control; and 4) a careful review of all health care policies and protocols to ensure that effective, organized responses are triggered when an infectious outbreak occurs.

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Salivary AsHPX12 influence pre-blood meal associated behavioral properties in the mosquito Anopheles stephensi

10.1101/2020.06.12.147959 ◽

2020 ◽

Cited By ~ 2

Author(s):

Seena Kumari ◽

Tanwee Das De ◽

Charu Chauhan ◽

Jyoti Rani ◽

Sanjay Tevatiya ◽

...

Keyword(s):

Salivary Gland ◽

Blood Meal ◽

Anopheles Stephensi ◽

Blood Feeding ◽

Vital Role ◽

Host Attraction ◽

Altered Expression ◽

Rnaseq Data ◽

Transcriptional Modulation ◽

Physiological Homeostasis

AbstractIn the adult female mosquito, successful blood meal acquisition is accomplished by salivary glands, which releases a cocktail of proteins to counteract vertebrate host’s immune-homeostasis. However, the biological relevance of many salivary proteins remains unknown. Here, we characterize a salivary specific Heme peroxidase family member HPX12, originally identified from Plasmodium vivax infected salivary RNAseq data of the mosquito Anopheles stephensi. We demonstrate that dsRNA silencing mediated mRNA depletion of salivary AsHPX12 (80-90%), causes enhanced host attraction but reduced blood-meal acquisition abilities, by increasing probing propensity (31%), as well as probing time (100–200s, P<0.0001) as compared to control (35-90s) mosquitoes group. Altered expression of the salivary secretory and antennal proteins may account for an unusual fast release of salivary cocktail proteins, but the slowing acquisition of blood meal, possibly due to salivary homeostasis disruption of AsHPX12 silenced mosquitoes. A parallel transcriptional modulation in response to blood feeding and P. vivax infection, further establish a possible functional correlation of AsHPX12 role in salivary immune-physiology and Plasmodium sporozoites survival/transmission. We propose that salivary HPX12 may have a vital role in the management of ‘pre- and post’-blood meal associated physiological-homeostasis and parasite transmission.Graphical abstractFigure 1:Schematic representation of mosquito’s blood meal acquisition and upshot on blood-feeding after silencing of salivary gland HPX-12. (A) After landing over host skin, mosquito mouthparts (proboscis) actively engaged to search, probe, and pierce the skin followed by a rapid release of the pre-synthesized salivary cocktail, which counteracts the host homeostasis, inflammation, and immune responses, during blood meal uptake. (B) Silencing of HPX-12 disrupts salivary gland homeostasis, enhancing mosquito attraction, possibly by up-regulating odorant-binding proteins genes-OBP-7,10 and OBP-20 expression in the Olfactory System. However, HPX-12 disruption may also cause significant effects on pre-blood meal associated probing abilities, which may be due to fast down-regulation of salivary cocktail proteins such as Anopheline, Apyrase, D7L proteins.

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