Biology subjects

Gingell, D. D.

Publications and source records attributed to Gingell, D. D..

4 recordsLinked to original sources

bioRxiv2026

Microbiota-driven, strain-specific Asaia colonisation modulates mosquito vector competence

Microbiota-based mosquito control strategies are founded on the ability of bacterial symbionts to modify host biology and/or pathogen transmission. However, symbionts do not operate in isolation. Their colonisation, persistence and biological effects arise within a complex ecological network comprising the host and its resident microbiota. We hypothesized that colonisation success is not only an intrinsic property of a bacterial symbiont but emerges from interactions between bacterial strain, host background, and the native microbial community. To test this, we compared recolonisation by endogenous and exogenous Asaia strains in the invasive mosquito Aedes koreicus using wild-type and axenic mosquitoes to experimentally manipulate the microbial composition. We found that endogenous and exogenous strains followed distinct colonisation trajectories. Depletion of the resident microbiota selectively rescued colonisation by the endogenous strain, whereas both strains successfully disseminated to transmission-relevant tissues despite contrasting early gut dynamics. Furthermore, these strain-specific colonisation dynamics were associated with increased Semliki Forest virus (SFV) transmission and enhanced adult longevity, particularly following colonisation by the exogenous strain. Our findings indicate that resident microbial communities act as selective ecological filters that shape symbiont colonisation in a strain-dependent manner. More broadly, this study demonstrates that the biological effects of mosquito symbionts emerge from interactions between bacterial strains and the microbial community context, providing an ecological framework for the rational and effective development of microbiota-based vector control strategies.

microbiology↗

bioRxiv2026

Thermal responses of an emerging temperate mosquito reshape arboviral transmission risk

Global warming is known to increase arboviral disease risk by enabling the expansion of tropical vectors such as Aedes aegypti and Aedes albopictus. However, whether climate-driven shifts in seasonal dynamics within temperate regions, such as warmer springs and shorter winters, create thermal settings favourable for additional vectors, which can reshape disease risk maps, is poorly understood. To answer this question, we used the invasive temperate mosquito species Aedes koreicus and tested its thermal developmental resilience, along with its vector competence for dengue and chikungunya viruses. We observed significant phenotypic variation in thermal tolerance across life stages, which translates into distinct thermal performance curves for life-history traits, ultimately shaping overall mosquito fitness. We further found that temperature effects are virus-specific, with differential impacts on infection and transmission between dengue and chikungunya viruses. These stage- and pathogen-specific responses generate carry-over effects across life stages, indicating that thermal responses may be constrained by life-history trade-offs rather than be defined by a single thermal optimum. Our results highlight the need to move beyond static, species-based risk assessments toward mechanistic frameworks that integrate thermal biology across life stages and vector-pathogen systems. As climate change increasingly reshapes seasonal structure rather than simply elevating mean temperatures, cold-adapted and temperate vectors such as Ae. koreicus, provide critical model systems to understand how transmission risk emerges outside mosquito classical thermal optima, calling for a broader paradigm shift in how global change and vector-borne disease risk are conceptualised.

ecology↗

bioRxiv2022

Validation of an engineered Zika virus-like particle vaccine candidate in a mosquito-mouse transmission model

The primary route of Zika virus (ZIKV) transmission is through the bite of an infected Aedes mosquito, when it probes the skin of a vertebrate host during a blood meal. Viral particles are injected into the bite site together with mosquito saliva and a complex mixture of other components. Some of them are shown to play a key role in the augmentation of the arbovirus infection in the host, with increased viremia and/or morbidity. This vector-derived contribution to the infection is not usually considered when vaccine candidates are tested in preclinical animal models. In this study, we performed a preclinical validation of a promising ZIKV vaccine candidate in a mosquito-mouse transmission model using both Asian and African ZIKV lineages. Mice were immunized with engineered ZIKV virus-like particles and subsequently infected through the bite of ZIKV-infected Ae. aegypti mosquitoes. Despite a mild increase in viremia in mosquito-infected mice compared to those infected through traditional needle injection, the vaccine protected the animals from developing the disease and strongly reduced viremia. In addition, during peak viremia, naive mosquitoes were allowed to feed on infected vaccinated and non-vaccinated mice. Our analysis of viral titers in mosquitos showed that the vaccine was able to inhibit virus transmission from the host to the vector. Author summaryZika is a mosquito-borne viral disease, causing acute debilitating symptoms and complications in infected individuals and irreversible neuronal abnormalities in newborn children. The primary vectors of ZIKV are generally considered to be mosquitoes of the genus Aedes, in particular Aedes aegypti. Despite representing a significant public health burden with a widespread transmission in many regions of the world, Zika remains a neglected disease with no effective antiviral therapies or approved vaccines to control and prevent infections. The efficacy of several promising candidate vaccines is however under investigation, mainly through artificial infections (i.e. needle-mediated injections of the virus) in animal models, while it is known that components of the mosquito bite lead to an enhancement of viral infection and spread. In this study, we have also included mosquitoes as viral vectors, demonstrating that the ability of a promising candidate vaccine to protect animals against ZIKV infections after the bite of an infected mosquito, and to also prevent its further transmission. These findings represent an additional crucial step for the development of an effective prevention tool for clinical use. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=150 SRC="FIGDIR/small/503125v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@136fd6borg.highwire.dtl.DTLVardef@137950borg.highwire.dtl.DTLVardef@1a0e01org.highwire.dtl.DTLVardef@8d90d7_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2020

High temperature cycles result in maternal transmission and dengue infection differences between Wolbachia strains in Aedes aegypti

Environmental factors play a crucial role in the population dynamics of arthropod endosymbionts, and therefore in the deployment of Wolbachia symbionts for the control of dengue arboviruses. The potential of Wolbachia to invade, persist and block virus transmission depends in part on its intracellular density. Several recent studies have highlighted the importance of larval rearing temperature in modulating Wolbachia densities in adults, suggesting that elevated temperatures can severely impact some strains, while having little effect on others. The effect of a replicated tropical heat cycle on Wolbachia density and levels of virus blocking was assessed using Aedes aegypti lines carrying strains wMel and wAlbB, two Wolbachia strains currently used for dengue control. Impacts on intracellular density, maternal transmission fidelity and dengue inhibition capacity were observed for wMel. In contrast wAlbB-carrying Ae. aegypti maintained a relatively constant intracellular density at high temperatures and conserved its capacity to inhibit dengue. Following larval heat treatment, wMel showed a degree of density recovery in aging adults, although this was compromised by elevated air temperatures. When choosing the Wolbachia strain to be used in a dengue control programme it is important to consider the effects of environmental temperatures on invasiveness and virus inhibition. Author summaryIn the past decades, dengue incidence has dramatically increased all over the world. An emerging dengue control strategy utilizes Ae. aegypti mosquitoes artificially transinfected with the bacterial symbiont Wolbachia, with the ultimate aim of replacing wild mosquito populations. Wolbachia is transmitted from mother to offspring and is able to interfere with virus transmission within the mosquito vector. However, the rearing temperature of mosquito larvae is known to impact on some Wolbachia strains. In this study, we compared the effects of a temperature cycle mimicking natural breeding sites in tropical climates on two Wolbachia strains, currently used for open field trials. We observed that the strain wMel was susceptible to high larval rearing temperatures, while the strain wAlbB resulted to be more stable. These results underlines the importance of understanding the impact of environmental factors on released mosquitoes, in order to ensure the most efficient strategy for dengue control.

microbiology↗