Reduction of Aedes aegypti Vector Competence for Dengue Virus under Large Temperature Fluctuations

Dengue fever (DF) is the most prevalent arthropod-borne viral disease which affects humans. DF is caused by the four dengue virus (DENV) serotypes, which are transmitted to the host by the mosquitoAedes aegyptithat has key roles in DENV infection, replication, and viral transmission (vector competence). Mosquito saliva also plays an important role during DENV transmission. In this study, we detected the presence of sialic acid (Sia) inAedes aegyptitissues, which may have an important role during DENV-vector competence. We also identified genome sequences encoding enzymes involved in Sia pathways. The cDNA forAedes aegyptiCMP-Sia synthase (CSAS) was amplified, cloned, and functionally evaluated via the complementation of LEC29.Lec32 CSAS-deficient CHO cells.AedesCSAS-transfected LEC29.Lec32 cells were able to express Sia moieties on the cell surface. Sequences related toα-2,6-sialyltransferase were detected in theAedes aegyptigenome. Likewise, we identified Sia-α-2,6-DENV interactions in different mosquito tissues. In addition, we evaluated the possible role of sialylated molecules in a salivary gland extract during DENV internalization in mammalian cells. The knowledge of early DENV-host interactions could facilitate a better understanding of viral tropism and pathogenesis to allow the development of new strategies for controlling DENV transmission.

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Acceptability of Aedes aegypti blood feeding on dengue virus-infected human volunteers for vector competence studies in Iquitos, Peru

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0007090 ◽

2019 ◽

Vol 13 (2) ◽

pp. e0007090 ◽

Cited By ~ 3

Author(s):

Amy C. Morrison ◽

Julia Schwarz ◽

Kanya C. Long ◽

Jhonny Cordova ◽

Jennifer E. Rios ◽

...

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Vector Competence ◽

Blood Feeding ◽

Human Volunteers

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Larval Exposure to the Bacterial Insecticide Bti Enhances Dengue Virus Susceptibility of Adult Aedes aegypti Mosquitoes

Insects ◽

10.3390/insects9040193 ◽

2018 ◽

Vol 9 (4) ◽

pp. 193 ◽

Cited By ~ 6

Author(s):

Isabelle Moltini-Conclois ◽

Renaud Stalinski ◽

Guillaume Tetreau ◽

Laurence Després ◽

Louis Lambrechts

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Adult Stage ◽

Vector Competence ◽

Life Stage ◽

Genetic Resistance ◽

Bacterial Pathogen ◽

Human Pathogens ◽

Resistant Strains ◽

Pathogen Exposure

Understanding the interactions between pathogens sharing the same host can be complicated for holometabolous animals when larval and adult stages are exposed to distinct pathogens. In medically important insect vectors, the effect of pathogen exposure at the larval stage may influence susceptibility to human pathogens at the adult stage. We addressed this hypothesis in the mosquito Aedes aegypti, a major vector of arthropod-borne viruses (arboviruses), such as the dengue virus (DENV) and the chikungunya virus (CHIKV). We experimentally assessed the consequences of sub-lethal exposure to the bacterial pathogen Bacillus thuringiensis subsp. israelensis (Bti), during larval development, on arbovirus susceptibility at the adult stage in three Ae. aegypti strains that differ in their genetic resistance to Bti. We found that larval exposure to Bti significantly increased DENV susceptibility, but not CHIKV susceptibility, in the Bti-resistant strains. However, there was no major difference in the baseline arbovirus susceptibility between the Bti-resistant strains and their Bti-susceptible parental strain. Although the generality of our results remains to be tested with additional arbovirus strains, this study supports the idea that the outcome of an infection by a pathogen depends on other pathogens sharing the same host even when they do not affect the same life stage of the host. Our findings may also have implications for Bti as a mosquito biocontrol agent, indicating that the sub-optimal Bti efficacy may have counter-productive effects by increasing vector competence, at least for some combinations of arbovirus and mosquito strains.

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Vector competence of Aedes aegypti from New Caledonia for the four recent circulating dengue virus serotypes

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0008303 ◽

2020 ◽

Vol 14 (5) ◽

pp. e0008303

Author(s):

Olivia O’Connor ◽

Elodie Calvez ◽

Catherine Inizan ◽

Nicolas Pocquet ◽

Vincent Richard ◽

...

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

New Caledonia ◽

Vector Competence ◽

Dengue Virus Serotypes

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Impact of daily temperature fluctuations on dengue virus transmission by Aedes aegypti

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1101377108 ◽

2011 ◽

Vol 108 (18) ◽

pp. 7460-7465 ◽

Cited By ~ 366

Author(s):

L. Lambrechts ◽

K. P. Paaijmans ◽

T. Fansiri ◽

L. B. Carrington ◽

L. D. Kramer ◽

...

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Virus Transmission ◽

Temperature Fluctuations ◽

Daily Temperature ◽

Daily Temperature Fluctuations

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Determining vector competence of Aedes aegypti from Ghana in transmitting dengue virus serotypes 1 and 2

Parasites & Vectors ◽

10.1186/s13071-021-04728-z ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Michael Amoa-Bosompem ◽

Daisuke Kobayashi ◽

Kentaro Itokawa ◽

Katsunori Murota ◽

Astri Nur Faizah ◽

...

Keyword(s):

Aedes Aegypti ◽

Dengue Virus ◽

Urban Areas ◽

Vector Competence ◽

Denv Infection ◽

West African ◽

Control Group ◽

African Countries ◽

Denv Serotypes ◽

Serotype 1

Abstract Background Dengue virus (DENV) is a mosquito-borne arbovirus transmitted by Aedes mosquitoes, but is not endemic in all areas where this vector is found. For example, the relatively sparse distribution of cases in West Africa is generally attributed to the refractory nature of West African Aedes aegypti (Ae. aegypti) to DENV infection, and particularly the forest-dwelling Ae. aegypti formosus. However, recent studies have shown these mosquitoes to be competent vectors within some West African countries that have suffered outbreaks in the past, such as Senegal. There is however little information on the vector competence of the Ae. aegypti in West African countries such as Ghana with no reported outbreaks. Methods This study examined the vector competence of 4 Ae. aegypti colonies from urban, semi-urban, and two rural locations in Ghana in transmitting DENV serotypes 1 and 2, using a single colony from Vietnam as control. Midgut infection and virus dissemination were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR), while the presence and concentration of DENV in the saliva of infectious mosquitoes was determined by the focus forming assay. Results There were significant differences in the colonies’ susceptibility to virus infection, dissemination, and transmission. All examined Ghanaian mosquitoes were refractory to infection by DENV serotype 2, while some colonies exhibited potential to transmit DENV serotype 1. None of the tested colonies were as competent as the control group colony. Conclusions These findings give insight into the possible risk of outbreaks, particularly in the urban areas in the south of Ghana, and highlight the need for continuous surveillance to determine the transmission status and outbreak risk. This study also highlights the need to prevent importation of different DENV strains and potential invasion of new highly vector-competent Ae. aegypti strains, particularly around the ports of entry. Graphic Abstract

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