scholarly journals Evolutionary transition from blood feeding to obligate nonbiting in a mosquito

2017 ◽  
Vol 115 (5) ◽  
pp. 1009-1014 ◽  
Author(s):  
William E. Bradshaw ◽  
Joshua Burkhart ◽  
John K. Colbourne ◽  
Rudyard Borowczak ◽  
Jacqueline Lopez ◽  
...  
Keyword(s):  
Blood Meal ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Evolutionary Transition ◽  
Genetic Changes ◽  
Wyeomyia Smithii ◽  
Extant Species ◽  
Starting Point ◽  
Differential Gene ◽  
Vector Borne

The spread of blood-borne pathogens by mosquitoes relies on their taking a blood meal; if there is no bite, there is no disease transmission. Although many species of mosquitoes never take a blood meal, identifying genes that distinguish blood feeding from obligate nonbiting is hampered by the fact that these different lifestyles occur in separate, genetically incompatible species. There is, however, one unique extant species with populations that share a common genetic background but blood feed in one region and are obligate nonbiters in the rest of their range: Wyeomyia smithii. Contemporary blood-feeding and obligate nonbiting populations represent end points of divergence between fully interfertile southern and northern populations. This divergence has undoubtedly resulted in genetic changes that are unrelated to blood feeding, and the challenge is to winnow out the unrelated genetic factors to identify those related specifically to the evolutionary transition from blood feeding to obligate nonbiting. Herein, we determine differential gene expression resulting from directional selection on blood feeding within a polymorphic population to isolate genetic differences between blood feeding and obligate nonbiting. We show that the evolution of nonbiting has resulted in a greatly reduced metabolic investment compared with biting populations, a greater reliance on opportunistic metabolic pathways, and greater reliance on visual rather than olfactory sensory input. W. smithii provides a unique starting point to determine if there are universal nonbiting genes in mosquitoes that could be manipulated as a means to control vector-borne disease.

scholarly journals Understanding mosquito host-choice behaviour: a new and low-cost method of identifying the sex of human hosts from mosquito blood meals

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Fiona Teltscher ◽  
Sophie Bouvaine ◽  
Gabriella Gibson ◽  
Paul Dyer ◽  
Jennifer Guest ◽  
...  
Keyword(s):  
Blood Meal ◽  
Host Species ◽  
Disease Transmission ◽  
Low Cost ◽  
Host Choice ◽  
Epidemiological Models ◽  
Choice Behaviour ◽  
Vector Borne ◽  
Transmission Models ◽  
Blood Meals

Abstract Background Mosquito-borne diseases are a global health problem, causing hundreds of thousands of deaths per year. Pathogens are transmitted by mosquitoes feeding on the blood of an infected host and then feeding on a new host. Monitoring mosquito host-choice behaviour can help in many aspects of vector-borne disease control. Currently, it is possible to determine the host species and an individual human host from the blood meal of a mosquito by using genotyping to match the blood profile of local inhabitants. Epidemiological models generally assume that mosquito biting behaviour is random; however, numerous studies have shown that certain characteristics, e.g. genetic makeup and skin microbiota, make some individuals more attractive to mosquitoes than others. Analysing blood meals and illuminating host-choice behaviour will help re-evaluate and optimise disease transmission models. Methods We describe a new blood meal assay that identifies the sex of the person that a mosquito has bitten. The amelogenin locus (AMEL), a sex marker located on both X and Y chromosomes, was amplified by polymerase chain reaction in DNA extracted from blood-fed Aedes aegypti and Anopheles coluzzii. Results AMEL could be successfully amplified up to 24 h after a blood meal in 100% of An. coluzzii and 96.6% of Ae. aegypti, revealing the sex of humans that were fed on by individual mosquitoes. Conclusions The method described here, developed using mosquitoes fed on volunteers, can be applied to field-caught mosquitoes to determine the host species and the biological sex of human hosts on which they have blood fed. Two important vector species were tested successfully in our laboratory experiments, demonstrating the potential of this technique to improve epidemiological models of vector-borne diseases. This viable and low-cost approach has the capacity to improve our understanding of vector-borne disease transmission, specifically gender differences in exposure and attractiveness to mosquitoes. The data gathered from field studies using our method can be used to shape new transmission models and aid in the implementation of more effective and targeted vector control strategies by enabling a better understanding of the drivers of vector-host interactions.

scholarly journals Haematophagous arthropod saliva and host defense system: a tale of tear and blood

2005 ◽  
Vol 77 (4) ◽  
pp. 665-693 ◽  
Author(s):  
Bruno B. Andrade ◽  
Clarissa R. Teixeira ◽  
Aldina Barral ◽  
Manoel Barral-Netto
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Host Defense ◽  
Blood Meal ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Defense System ◽  
Current Information ◽  
System A ◽  
Host Defense System

The saliva from blood-feeding arthropod vectors is enriched with molecules that display diverse functions that mediate a successful blood meal. They function not only as weapons against host's haemostatic, inflammatory and immune responses but also as important tools to pathogen establishment. Parasites, virus and bacteria taking advantage of vectors' armament have adapted to facilitate their entry in the host. Today, many salivary molecules have been identified and characterized as new targets to the development of future vaccines. Here we focus on current information on vector's saliva and the molecules responsible to modify host's hemostasis and immune response, also regarding their role in disease transmission.

scholarly journals Assessing the blood-host plasticity and dispersal rate of the malaria vector Anopheles coluzzii

2018 ◽  
Author(s):  
James Orsborne ◽  
Luis Furuya-Kanamori ◽  
Claire L. Jeffries ◽  
Mojca Kristan ◽  
Abdul Rahim Mohammed ◽  
...  
Keyword(s):  
Blood Meal ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Host Choice ◽  
Anopheles Coluzzii ◽  
Dispersal Rate ◽  
Blood Digestion ◽  
Novel Method ◽  
Blood Meal Digestion ◽  
Blood Meals

AbstractDifficulties with observing the dispersal of insect vectors in the field have hampered understanding of several aspects of their behaviour linked to disease transmission. Here, a novel method based on detection of blood-meal sources is introduced to inform two critical and understudied mosquito behaviours: plasticity in the malaria vector’s blood-host choice and vector dispersal. Strategically located collections of Anopheles coluzzii from a malaria-endemic village of southern Ghana showed statistically significant variation in host species composition of mosquito blood-meals. Trialling a new sampling approach gave the first estimates for the remarkably local spatial scale across which host choice is plastic. Using quantitative PCR, the blood-meal digestion was then quantified for field-caught mosquitoes and calibrated according to timed blood digestion in colony mosquitoes. We demonstrate how this new ‘molecular Sella score’ approach can be used to estimate the dispersal rate of blood-feeding vectors caught in the field.

scholarly journals Novel small molecule agonists of an Aedes aegypti neuropeptide Y receptor block mosquito biting behavior

2018 ◽  
Author(s):  
Laura B. Duvall ◽  
Lavoisier Ramos-Espiritu ◽  
Kyrollos E. Barsoum ◽  
J. Fraser Glickman ◽  
Leslie B. Vosshall
Keyword(s):  
Aedes Aegypti ◽  
Neuropeptide Y ◽  
Small Molecule ◽  
Blood Meal ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Behavioral Suppression ◽  
Host Seeking ◽  
Novel Approach ◽  
Seeking Behavior

AbstractFemale Aedes aegypti mosquitoes bite humans to obtain a blood-meal to develop their eggs. Remarkably, strong attraction to humans is suppressed for several days after the blood-meal by an unknown mechanism. We investigated a role for neuropeptide Y (NPY)-related signaling in this long-term behavioral suppression, and discovered that drugs targeting human NPY receptors modulate mosquito host-seeking behavior. In a screen of all 49 predicted Ae. aegypti peptide receptors, we identified NPY-like receptor 7 (NPYLR7) as the sole target of these human drugs. To obtain small molecule agonists selective for NPYLR7, we carried out a high-throughput cell-based assay of 265,211 compounds, and isolated 6 highly selective NPYLR7 agonists that inhibit mosquito attraction to humans. NPYLR7 CRISPR-Cas9 null mutants are defective in behavioral suppression, and resistant to these drugs. Finally, we show that these drugs are capable of inhibiting biting and blood-feeding on a live host, suggesting a novel approach to control infectious disease transmission by controlling mosquito behavior.

scholarly journals Sub-lethal insecticide exposure affects host biting efficiency of Kdr-resistant Anopheles gambiae

2019 ◽  
Author(s):  
Malal M Diop ◽  
Fabrice Chandre ◽  
Marie Rossignol ◽  
Angélique Porciani ◽  
Mathieu Chateau ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Blood Meal ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Meal Size ◽  
Insecticide Treated Nets ◽  
Feeding Success ◽  
Insecticide Exposure ◽  
Biting Behaviour ◽  
Blood Meal Size

AbstractThe massive use of insecticide-treated nets (ITNs) has drastically changed the environment for malaria vector mosquitoes, challenging their host-seeking behaviour and biting success. Here, we investigated the effect of a brief exposure to an ITN on the biting behaviour of Anopheles mambiae mosquitoes and the interaction between such behaviour and the kdr mutation that confers resistance to pyrethroids. To this aim, we developed a video assay to study the biting behaviour of mosquitoes with similar genetic background, but different kdr locus genotypes (SS i.e. homozygous susceptible, RS i.e. heterozygous and RR i.e. homozygous resistant), after a brief exposure to either control untreated nets or one of two types of pyrethroid-treated nets (deltamethrin or permethrin). In presence of untreated nets, the kdr mutation did not influence mosquito blood feeding success but caused differences in feeding and prediuresis durations and blood meal size. Exposure to deltamethrin ITN decreased the blood feeding success rate of RR and RS mosquitoes, whereas in presence of permethrin ITN, the kdr mutation increased the blood-feeding success of mosquitoes. Exposure to the two types of pyrethroid-treated nets reduced feeding duration, prediuresis duration and blood meal size of all three genotypes. Our study demonstrates a complex interaction between insecticide exposure and the kdr mutation on the biting behavior of mosquitoes, which may substantially impact malaria vector fitness and disease transmission.

scholarly journals The Taste of Blood in Mosquitoes

2020 ◽  
Author(s):  
Veronica Jové ◽  
Zhongyan Gong ◽  
Felix J.H. Hol ◽  
Zhilei Zhao ◽  
Trevor R. Sorrells ◽  
...  
Keyword(s):  
Calcium Imaging ◽  
Disease Transmission ◽  
Blood Feeding ◽  
Metabolic Energy ◽  
Sexually Dimorphic ◽  
Blood Components ◽  
Feeding Programs ◽  
Vector Borne ◽  
Innate Ability

SUMMARYBlood-feeding mosquitoes survive by feeding on nectar for metabolic energy, but to develop eggs, females require a blood meal. Aedes aegypti females must accurately discriminate between blood and nectar because detection of each meal promotes one of two mutually exclusive feeding programs characterized by distinct sensory appendages, meal sizes, digestive tract targets, and metabolic fates. We investigated the role of the syringe-like blood-feeding appendage, the stylet, and discovered that sexually dimorphic stylet neurons are the first to taste blood. Using pan-neuronal GCaMP calcium imaging, we found that blood is detected by four functionally distinct classes of stylet neurons, each tuned to specific blood components associated with diverse taste qualities. Furthermore, the stylet is specialized to detect blood over nectar. Stylet neurons are insensitive to nectar-specific sugars and responses to glucose, the sugar found in both blood and nectar, depend on the presence of additional blood components. The distinction between blood and nectar is therefore encoded in specialized neurons at the very first level of sensory detection in mosquitoes. This innate ability to recognize blood is the basis of vector-borne disease transmission to millions of people world-wide.

scholarly journals Assessing the blood meal hosts of Culex quinquefasciatus and Aedes taeniorhynchus in Isla Santa Cruz, Galápagos

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Samoa Asigau ◽  
Sawsan Salah ◽  
Patricia G. Parker
Keyword(s):  
Feeding Behavior ◽  
Culex Quinquefasciatus ◽  
Blood Meal ◽  
Disease Transmission ◽  
Avian Malaria ◽  
Mosquito Species ◽  
Blood Feeding ◽  
Santa Cruz ◽  
Aedes Taeniorhynchus ◽  
Blood Meals

Abstract Background Blood meal host selection by mosquito vectors is an important component in understanding disease dynamics of pathogens that threaten endemic fauna in isolated islands such as Galápagos. Research on the feeding behavior of mosquitoes can provide clues to the hosts and vectors involved in disease transmission. This information is particularly critical for endemic wildlife fauna in island systems that have evolved without resistance to novel diseases such as avian malaria. The aims of this study were to determine the blood-feeding patterns of two species of mosquitoes found in Galápagos and discuss how their feeding behavior may influence the transmission of pathogens such as avian malaria. Methods In the summer of 2015, we sampled two mosquito species (Aedes taeniorhynchus and Culex quinquefasciatus) across 18 different sites on Isla Santa Cruz, which is the second largest island in Galápagos and has the largest human population. We trapped mosquitoes using CDC light traps and CDC gravid traps and identified sources of blood meals for engorged mosquitoes by sequencing a portion of the vertebrate mitochondrial cytochrome b gene. Results Out of 947 female mosquitoes captured, 320 were blood-fed, and PCR amplifications were successful for 301 of the blood meals. Results revealed that both Aedes taeniorhynchus and Culex quinquefasciatus feed from a variety of vertebrate taxa, numerically dominated by humans on Isla Santa Cruz. Conclusions The high proportion of mammalian blood meals could represent locally available and abundant hosts on Santa Cruz. However, host surveys and estimates of relative abundances of vertebrate species will need to accompany mosquito trapping studies on non-inhabited and inhabited islands in Galápagos to further validate this.

scholarly journals Iron and Ferritin Deposition in the Ovarian Tissues of the Yellow Fever Mosquito (Diptera: Culicidae)

2019 ◽  
Vol 19 (5) ◽  
Author(s):  
Dawn L Geiser ◽  
Theresa N Thai ◽  
Maria B Love ◽  
Joy J Winzerling
Keyword(s):  
Yellow Fever ◽  
Light Chain ◽  
Blood Meal ◽  
Blood Feeding ◽  
Yellow Fever Mosquito ◽  
Vector Borne Diseases ◽  
Ferritin Heavy Chain ◽  
Essential Nutrient ◽  
Vector Borne ◽  
And Storage

Abstract Dengue, yellow fever, and Zika are viruses transmitted by yellow fever mosquito, Aedes aegypti [Linnaeus (Diptera: Culicidae)], to thousands of people each year. Mosquitoes transmit these viruses while consuming a blood meal that is required for oogenesis. Iron, an essential nutrient from the blood meal, is required for egg development. Mosquitoes receive a high iron load in the meal; although iron can be toxic, these animals have developed mechanisms for dealing with this load. Our previous research has shown iron from the blood meal is absorbed in the gut and transported by ferritin, the main iron transport and storage protein, to the ovaries. We now report the distribution of iron and ferritin in ovarian tissues before blood feeding and 24 and 72 h post-blood meal. Ovarian iron is observed in specific locations. Timing post-blood feeding influences the location and distribution of the ferritin heavy-chain homolog, light-chain homolog 1, and light-chain homolog 2 in ovaries. Understanding iron deposition in ovarian tissues is important to the potential use of interference in iron metabolism as a vector control strategy for reducing mosquito fecundity, decreasing mosquito populations, and thereby reducing transmission rates of vector-borne diseases.

scholarly journals Long-term impact of a ten-year intervention program on human and canine Trypanosoma cruzi infection in the Argentine Chaco

2021 ◽  
Vol 15 (5) ◽  
pp. e0009389
Author(s):  
Marta Victoria Cardinal ◽  
Gustavo Fabián Enriquez ◽  
Natalia Paula Macchiaverna ◽  
Hernán Darío Argibay ◽  
María del Pilar Fernández ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Disease Transmission ◽  
Intervention Program ◽  
Substantial Reduction ◽  
Triatoma Infestans ◽  
Incident Case ◽  
Cross Sectional ◽  
Vector Borne ◽  
Long Term Impact

Background Interruption of domestic vector-borne transmission of Trypanosoma cruzi is still an unmet goal in several American countries. In 2007 we launched a long-term intervention program aimed to suppress house infestation with the main domestic vector in southern South America (Triatoma infestans) and domestic transmission in Pampa del Indio, a resource-constrained, hyperendemic municipality with 1446 rural houses inhabited by Creole and indigenous people, in the Argentine Chaco ecoregion. Here, we assessed whether the 10-year insecticide-based program combined with community mobilization blocked vector-borne domestic transmission of T. cruzi to humans and dogs. Methods We carried out two municipality-wide, cross-sectional serosurveys of humans and dogs (considered sentinel animals) during 2016–2017 to compare with baseline data. We used a risk-stratified random sampling design to select 273 study houses; 410 people from 180 households and 492 dogs from 151 houses were examined for antibodies to T. cruzi using at least two serological methods. Results The seroprevalence of T. cruzi in children aged <16 years was 2.5% in 2017 (i.e., 4- to 11-fold lower than before interventions). The mean annual force of child infection (λ) sharply decreased from 2.18 to 0.34 per 100 person-years in 2017. One of 102 children born after interventions was seropositive for T. cruzi; he had lifetime residence in an apparently uninfested house, no outside travel history, and his mother was T. cruzi-seropositive. No incident case was detected among 114 seronegative people of all ages re-examined serologically. Dog seroprevalence was 3.05%. Among native dogs, λ in 2016 (1.21 per 100 dog-years) was 5 times lower than at program onset. Six native adult dogs born after interventions and with stable lifetime residence were T. cruzi-seropositive: three had exposure to T. infestans at their houses and one was an incident case. Conclusions These results support the interruption of vector-borne transmission of T. cruzi to humans in rural Pampa del Indio. Congenital transmission was the most likely source of the only seropositive child born after interventions. Residual transmission to dogs was likely related to transient infestations and other transmission routes. Sustained vector control supplemented with human chemotherapy can lead to a substantial reduction of Chagas disease transmission in the Argentine Chaco.

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