Microbiota potentialized larvicidal action of imidazolium salts against Aedes aegypti (Diptera: Culicidae)

Abstract Mosquitoes are important vectors of pathogens due to their blood feeding behavior. Aedes aegypti (Diptera: Culicidae) transmits arboviruses, such as dengue, Zika, and Chikungunya. This species carries several bacteria that may be beneficial for its biological and physiological development. Therefore, studying the response of its microbiota to chemical products could result in vector control. Recently, imidazolium salts (IS) were identified as effective Ae. aegypti larvicides. Considering the importance of the mosquito microbiota, this study addressed the influence of IS on the bacteria of Ae. aegypti larvae. After exposition of larvae to different IS concentrations, the cultured microbiota was identified through culturomics and mass spectrometry, and the non-cultivated microbiota was characterized by molecular markers. In addition, the influence of the IS on axenic larvae was studied for comparison. There was an alteration in both cultivable species and in their diversity, including modifications in bacterial communities. The axenic larvae were less susceptible to the IS, which was increased after exposing these larvae to bacteria of laboratory breeding water. This highlights the importance of understanding the role of the larval microbiota of Ae. aegypti in the development of imidazolium salt-based larvicides. Such effect of IS towards microbiota of Ae. aegypti larvae, through their antimicrobial action, increases their larvicidal potential.

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Visual threats reduce blood-feeding and trigger escape responses in Aedes aegypti mosquitoes.

10.1101/2022.01.08.475512 ◽

2022 ◽

Author(s):

Nicole E Wynne ◽

Karthikeyan Chandrasegaran ◽

Lauren Fryzlewicz ◽

Clément Vinauger

Keyword(s):

Aedes Aegypti ◽

Behavioral Response ◽

Visual Information ◽

Visual Cues ◽

Blood Feeding ◽

Potential Threat ◽

Visual Component ◽

Defensive Behaviors ◽

Escape Responses

The diurnal mosquitoes Aedes aegypti are vectors of several arboviruses, including dengue, yellow fever, and Zika viruses. To find a host to feed on, they rely on the sophisticated integration of olfactory, visual, thermal, and gustatory cues reluctantly emitted by the hosts. If detected by their target, this latter may display defensive behaviors that mosquitoes need to be able to detect and escape. In humans, a typical response is a swat of the hand, which generates both mechanical and visual perturbations aimed at a mosquito. While the neuro-sensory mechanisms underlying the approach to the host have been the focus of numerous studies, the cues used by mosquitoes to detect and identify a potential threat remain largely understudied. In particular, the role of vision in mediating mosquitoes' ability to escape defensive hosts has yet to be analyzed. Here, we used programmable visual displays to generate expanding objects sharing characteristics with the visual component of an approaching hand and quantified the behavioral response of female mosquitoes. Results show that Ae. aegypti is capable of using visual information to decide whether to feed on an artificial host mimic. Stimulations delivered in a LED flight arena further reveal that landed females Ae. aegypti display a stereotypical escape strategy by taking off at an angle that is a function of the distance and direction of stimulus introduction. Altogether, this study demonstrates mosquitoes can use isolated visual cues to detect and avoid a potential threat.

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The role of specific ammonia transporters in ammonia excretion in the blood feeding female mosquito,Aedes aegypti

10.1603/ice.2016.117444 ◽

2016 ◽

Author(s):

Andrea Claire Durant

Keyword(s):

Aedes Aegypti ◽

Ammonia Excretion ◽

Blood Feeding ◽

Female Mosquito

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Modulation of acyl-carnitines, the broad mechanism behind Wolbachia-mediated inhibition of medically important flaviviruses in Aedes aegypti

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1914814117 ◽

2020 ◽

Vol 117 (39) ◽

pp. 24475-24483 ◽

Cited By ~ 2

Author(s):

Gayathri Manokaran ◽

Heather A. Flores ◽

Conor T. Dickson ◽

Vinod K. Narayana ◽

Komal Kanojia ◽

...

Keyword(s):

Mass Spectrometry ◽

Liquid Chromatography ◽

Aedes Aegypti ◽

Zika Virus ◽

Liquid Chromatography Mass Spectrometry ◽

Comprehensive Picture ◽

Infected Cells ◽

Virus Blocking ◽

Flavivirus Infection

Wolbachia-infected mosquitoes are refractory to flavivirus infections, but the role of lipids in Wolbachia-mediated virus blocking remains to be elucidated. Here, we use liquid chromatography mass spectrometry to provide a comprehensive picture of the lipidome of Aedes aegypti (Aag2) cells infected with Wolbachia only, either dengue or Zika virus only, and Wolbachia-infected Aag2 cells superinfected with either dengue or Zika virus. This approach identifies a class of lipids, acyl-carnitines, as being down-regulated during Wolbachia infection. Furthermore, treatment with an acyl-carnitine inhibitor assigns a crucial role for acyl-carnitines in the replication of dengue and Zika viruses. In contrast, depletion of acyl-carnitines increases Wolbachia density while addition of commercially available acyl-carnitines impairs Wolbachia production. Finally, we show an increase in flavivirus infection of Wolbachia-infected cells with the addition of acyl-carnitines. This study uncovers a previously unknown role for acyl-carnitines in this tripartite interaction that suggests an important and broad mechanism that underpins Wolbachia-mediated pathogen blocking.

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The Salivary Adenosine Deaminase Activity of the MosquitoesCulex quinquefasciatusandAedes aegypti

Journal of Experimental Biology ◽

10.1242/jeb.204.11.2001 ◽

2001 ◽

Vol 204 (11) ◽

pp. 2001-2010 ◽

Cited By ~ 5

Author(s):

José M. C. Ribeiro ◽

Rosane Charlab ◽

Jesus G. Valenzuela

Keyword(s):

Aedes Aegypti ◽

Adenosine Deaminase ◽

Culex Quinquefasciatus ◽

Pain Perception ◽

Blood Feeding ◽

Mast Cell Degranulation ◽

Amp Deaminase ◽

Significant Similarity ◽

Adenosine Deaminase Activity

SUMMARYA cDNA coding for a protein with significant similarity to adenosine deaminase (ADA) was found while randomly sequencing a cDNA library constructed from salivary gland extracts of adult female Culex quinquefasciatus. Prompted by this result, we found high ADA activities in two culicine mosquitoes, Culex quinquefasciatus and Aedes aegypti, but not in the anopheline Anopheles gambiae. Homogenates from Culex quinquefasciatus also have an AMP deaminase activity that is three times greater than the ADA activity, whereas in Aedes aegypti the AMP deaminase activity is less than 10% of the ADA activity. Evidence for secretion of ADA during blood feeding by Aedes aegypti includes the presence of ADA activity in warm solutions probed through a membrane by mosquitoes and in serotonin-induced saliva and a statistically significant reduction in the levels of the enzyme in Aedes aegypti following a blood meal. We could not demonstrate, however, that C. quinquefasciatus secrete ADA in their saliva. Male Aedes aegypti and C. quinquefasciatus, which do not feed on blood, have less than 3% of the levels of ADA found in females. We propose that ADA activity in A. aegypti may help blood feeding by removing adenosine, a molecule associated with both the initiation of pain perception and the induction of mast cell degranulation in vertebrates, and by producing inosine, a molecule that potently inhibits the production of inflammatory cytokines. The role of salivary ADA in Culex quinquefasciatus remains unclear.

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Role of mass spectrometry in the purification of peptides and proteins

Journal of Chromatography B ◽

10.1016/s0021-9673(02)01795-8 ◽

2003 ◽

Author(s):

C Mazza

Keyword(s):

Mass Spectrometry

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THE ROLE OF BACTERIAL COMMUNITIES ON IN-SITU ARSENIC AND IRON CYCLING IN RIVERBANKS ALONG THE MEGHNA RIVER, BANGLADESH

10.1130/abs/2020am-357913 ◽

2020 ◽

Author(s):

Kimberly D. Myers ◽

◽

Katrina Lee Jewell ◽

P.S.K. Knappett ◽

Mehtaz M. Lipsi ◽

...

Keyword(s):

Bacterial Communities ◽

Iron Cycling

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Tick Ecdysteroid Hormone, Global Microbiota/Rickettsia Signaling in the Ovary versus Carcass during Vitellogenesis in Part-Fed (Virgin) American Dog Ticks, Dermacentor variabilis

Microorganisms ◽

10.3390/microorganisms9061242 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1242

Author(s):

Loganathan Ponnusamy ◽

Haley Sutton ◽

Robert D. Mitchell ◽

Daniel E. Sonenshine ◽

Charles S. Apperson ◽

...

Keyword(s):

Hormonal Regulation ◽

Natural Populations ◽

Blood Feeding ◽

Dermacentor Variabilis ◽

Transovarial Transmission ◽

Rickettsia Species ◽

Adult Females ◽

Dog Tick ◽

Total Bacteria

The transovarial transmission of tick-borne bacterial pathogens is an important mechanism for their maintenance in natural populations and transmission, causing disease in humans and animals. The mechanism for this transmission and the possible role of tick hormones facilitating this process have never been studied. Injections of physiological levels of the tick hormone, 20-hydroxyecdysone (20E), into part-fed (virgin) adult females of the American dog tick, Dermacentor variabilis, attached to the host caused a reduction in density of Rickettsia montanensis in the carcass and an increase in the ovaries compared to buffer-injected controls. This injection initiates yolk protein synthesis and uptake by the eggs but has no effect on blood feeding. Francisella sp. and R. montanensis were the predominant bacteria based on the proportionality in the carcass and ovary. The total bacteria load increased in the carcass and ovaries, and bacteria in the genus Pseudomonas increased in the carcass after the 20E injection. The mechanism of how the Rickettsia species respond to changes in tick hormonal regulation needs further investigation. Multiple possible mechanisms for the proliferation of R. montanensis in the ovaries are proposed.

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