Biology subjects

Briolant, S.

Publications and source records attributed to Briolant, S..

5 recordsLinked to original sources

bioRxiv2023

Multiplexed amplicon sequencing reveals the heterogeneous spatial distribution of pyrethroid resistance mutations in Aedes albopictus mosquito populations in Southern France.

The risk of mosquito-borne diseases transmission is moving fast toward temperate climates with the colonization and proliferation of the Asian tiger mosquito vector Aedes albopictus and the rapid and mass transport of passengers returning from tropical regions where the viruses are endemic. The prevention of major Aedes-borne viruses heavily relies on the use of insecticides for vector control, mainly pyrethroids In Europe. High-throughput molecular assays can provide a cost-effective surrogate to phenotypic insecticide resistance assays when mutations have been previously linked to a resistance phenotype. Here, we screened for the spatial distribution of kdr mutations at a large scale using a two-step approach based on multiplexed amplicon sequencing and an unprecedented collection of field-derived mosquitoes in South of France. We identified the presence of the V1016G allele in 14 sites. The V1016G allele was predominantly found in South-East France close to the Italian border with two additional isolated sites close to Bordeaux and Marmande. All mosquitoes were heterozygous for this mutation and should not be phenotypically resistant to pyrethroid insecticide. Four other mutations were identified in our targeted genomic sequence: I1532T, M1006L, M1586L, M995L. Sequencing a section of maternally inherited mitochondrial genome confirmed that the spread of Ae. albopictus in France originated from founders with haplogroup A1. These findings contribute to the broader understanding of resistance dynamics in Europe and can inform targeted approaches to mitigate the impact of resistance on vector control.

genetics↗

bioRxiv2021

Mosquito excreta reveals circulation of West Nile virus and its underlying ecosystem

Emerging and endemic mosquito-borne viruses can be difficult to detect and monitor because they often cause asymptomatic infections in human or vertebrate animals or cause nonspecific febrile illness with a short recovery waiting period. Cases detection in vertebrate hosts can be complemented by entomological surveillance, but this method is not adapted to low infection rates in mosquito populations that typically occur in low or non-endemic areas. We identified West Nile Virus circulation in Camargue, a wetland area in South of France, using a cost effective innovative xenomonitoring method based on the molecular detection of virus in excreta from trapped mosquitoes. We also succeeded at identifying the mosquito community diversity dynamic on several sampling sites, together with the vertebrate hosts on which they fed prior to be captured using amplicon-based metagenomic on mosquito excreta without processing any mosquito. Mosquito excreta-based virus surveillance can be considered as a cost-effective and non-invasive strategy that offers the additional asset to reveal the ecological network underlying arbovirus circulation.

ecology↗

bioRxiv2020

Variation in pyrethroid resistance phenotypes in Anopheles darlingi from residual malaria transmission area: warning on suspected resistance built-up in French Guiana.

Anopheles darlingi is the major vector of malaria in South America. In French Guiana, malaria transmission occurs inland and along the rivers with a particular reemergence in the lower Oyapock area. Control against malaria vector is performed using deltamethrin indoor residual spraying and long lasting impregnated bednets. For four years, the level of resistance to pyrethroids was monitored using CDC bottle tests in An. darlingi populations. Resistance built-up was suspected in a mosquito population in malaria endemic area but did not sustained, supposably due to the reintroduction of susceptible alleles. No mutation on the insecticide target genes was found, metabolic resistance is then suspected.

zoology↗

bioRxiv2020

Identification of French Guiana anopheline mosquitoes by MALDI-TOF MS profiling using protein signatures from two body parts.

In French Guiana, the malaria, a parasitic infection transmitted by Anopheline mosquitoes, remains a disease of public health importance. To prevent malaria transmission, the main effective way remains Anopheles control. For an effective control, accurate Anopheles species identification is indispensable to distinguish malaria vectors from non-vectors. Although, morphological and molecular methods are largely used, an innovative tool, based on protein pattern comparisons, the Matrix Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) profiling, emerged this last decade for arthropod identification. However, the limited mosquito fauna diversity of reference MS spectra remains one of the main drawback for it large usage. The aim of the present study was then to create and to share reference MS spectra for the identification of French Guiana Anopheline species. A total of eight distinct Anopheles species, among which four are malaria vectors, were collected in 6 areas. To improve Anopheles identification, two body parts, legs and thoraxes, were independently submitted to MS for the creation of respective reference MS spectra database (DB). This study underlined that double checking by MS enhanced the Anopheles identification confidence and rate of reliable classification. The sharing of this reference MS spectra DB should made easier Anopheles species monitoring in endemic malaria area to help malaria vector control or elimination programs.

microbiology↗

bioRxiv2019

European and tropical Aedes albopictus mosquito populations have similar systemic Zika virus infection dynamics

First isolated from a forest in East Africa in the mid-20th century, Zika virus (ZIKV) has now emerged worldwide in urbanized areas where its mosquito vectors, mainly Aedes aegypti and Ae. albopictus, are present. Europe and French overseas territories in the Indian Ocean have been so far spared despite the presence of Ae. albopictus, the Asian tiger mosquito. However, because they have strong economic and touristic links with regions affected by ZIKV, French territories in the Indian Ocean have a high risk of introduction. Here, we assess the susceptibility of two Ae. albopictus populations from Metropolitan France and the Reunion island (a French oversea territory in the Indian Ocean) for a ZIKV isolate from the Asian genotype at a titer ranging from 3 to 7.5 x 106 focus-forming units per milliliter. High infection rates and unpreceded levels of systemic infection rates were observed in both Metropolitan France and the Reunion island populations, without differences in infection rates or intra-mosquito systemic infection dynamics between the two mosquito populations. Ten and 20-days were needed by the virus to disseminate in 50% and 100% of the exposed mosquitoes respectively. Such slow intra-mosquito viral dynamics, in addition to repeatedly reported high transmission barrier in the literature, can impact ZIKV transmission when potentially vectored by Ae. albopictus. However, because mosquito-borne virus intra-host transmission dynamics can be influenced by numerous factors, including virus dose dynamics inside infectious humans or viral evolution towards shorter extrinsic incubation periods (EIP), our results highlight that Ae. albopictus populations present in Metropolitan France and the French territoires in the Indian Ocean might become potential vector for autochthonous ZIKV transmissions.

microbiology↗