More Like this

1. A cryopreservation method to recover laboratory- and field-derived bacterial communities from mosquito larval habitats

   https://doi.org/10.1371/journal.pntd.0011234  

   Zhao, Serena Y. ; Hughes, Grant L. ; Coon, Kerri L. ( April 2023 , PLOS Neglected Tropical Diseases)

   Bartholomay, Lyric C. (Ed.)

   Mosquitoes develop in a wide range of aquatic habitats containing highly diverse and variable bacterial communities that shape both larval and adult traits, including the capacity of adult females of some mosquito species to transmit disease-causing organisms to humans. However, while most mosquito studies control for host genotype and environmental conditions, the impact of microbiota variation on phenotypic outcomes of mosquitoes is often unaccounted for. The inability to conduct reproducible intra- and inter-laboratory studies of mosquito-microbiota interactions has also greatly limited our ability to identify microbial targets for mosquito-borne disease control. Here, we developed an approach to isolate and cryopreserve bacterial communities derived from lab and field-based larval rearing environments of the yellow fever mosquito Aedes aegypti –a primary vector of dengue, Zika, and chikungunya viruses. We then validated the use of our approach to generate experimental microcosms colonized by standardized lab- and field-derived bacterial communities. Our results overall reveal minimal effects of cryopreservation on the recovery of both lab- and field-derived bacteria when directly compared with isolation from non-cryopreserved fresh material. Our results also reveal improved reproducibility of bacterial communities in replicate microcosms generated using cryopreserved stocks over fresh material. Communities in replicate microcosms further captured the majority of total bacterial diversity present in both lab- and field-based larval environments, although the relative richness of recovered taxa as compared to non-recovered taxa was substantially lower in microcosms containing field-derived bacteria. Altogether, these results provide a critical next step toward the standardization of mosquito studies to include larval rearing environments colonized by defined microbial communities. They also lay the foundation for long-term studies of mosquito-microbe interactions and the identification and manipulation of taxa with potential to reduce mosquito vectorial capacity. 

   more » « less
2. Microplastic ingestion perturbs the microbiome of Aedes albopictus (Diptera: Culicidae) and Aedes aegypti

   https://doi.org/10.1093/jme/tjad097  

   Edwards, Carla-Cristina ; McConnel, Gabriella ; Ramos, Daniela ; Gurrola-Mares, Yaizeth ; Dhondiram Arole, Kailash ; Green, Micah J. ; Cañas-Carrell, Jaclyn E. ; Brelsfoard, Corey L. ; Hillyer, ed., Julian ( July 2023 , Journal of Medical Entomology)

   Microplastics (MPs) are common environmental pollutants; however, little is known about their effects after ingestion by insects. Here we fed Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) mosquito larvae 1 µm polystyrene MPs and examined the impacts of ingestion on adult emergence rates, gut damage, and fungal and bacterial microbiota. Results show that MPs accumulate in the larval guts, resulting in gut damage. However, little impact on adult emergence rates was observed. MPs are also found in adult guts postemergence from the pupal stage, and adults expel MPs in their frass after obtaining sugar meals. Moreover, MPs effects on insect microbiomes need to be better defined. To address this knowledge gap, we investigated the relationship between MP ingestion and the microbial communities in Ae. albopictus and Ae. aegypti. The microbiota composition was altered by the ingestion of increasing concentrations of MPs. Amplicon sequence variants (ASVs) that contributed to differences in the bacterial and fungal microbiota composition between MP treatments were from the genera Elizabethkingia and Aspergillus, respectively. Furthermore, a decrease in the alpha diversity of the fungal and bacterial microbiota was observed in treatments where larvae ingested MPs. These results highlight the potential for the bacterial and fungal constituents in the mosquito microbiome to respond differently to the ingestion of MPs. Based on our findings and the effects of MP ingestion on the mosquito host micro- and mycobiome, MP pollution could impact the vector competence of important mosquito-transmitted viruses and parasites that cause human and animal diseases.

    

   more » « less
3. Aedes aegypti gut transcriptomes respond differently to microbiome transplants from field‐caught or laboratory‐reared mosquitoes

   https://doi.org/10.1111/1462-2920.16576  

   Hegde, Shivanand ; Brettell, Laura E. ; Quek, Shannon ; Etebari, Kayvan ; Saldaña, Miguel A. ; Asgari, Sassan ; Coon, Kerri L. ; Heinz, Eva ; Hughes, Grant L. ( January 2024 , Environmental Microbiology)

   The mosquito microbiome is critical for host development and plays a major role in many aspects of mosquito biology. While the microbiome is commonly dominated by a small number of genera, there is considerable variation in composition among mosquito species, life stages, and geography. How the host controls and is affected by this variation is unclear. Using microbiome transplant experiments, we asked whether there were differences in transcriptional responses when mosquitoes of different species were used as microbiome donors. We used microbiomes from four different donor species spanning the phylogenetic breadth of the Culicidae, collected either from the laboratory or the field. We found that when recipients received a microbiome from a donor reared in the laboratory, the response was remarkably similar regardless of donor species. However, when the donor had been collected from the field, many more genes were differentially expressed. We also found that while the transplant procedure did have some effect on the host transcriptome, this is likely to have had a limited effect on mosquito fitness. Overall, our results highlight the possibility that variation in mosquito microbiome communities is associated with variability in host–microbiome interactions and further demonstrate the utility of the microbiome transplantation technique for investigating host–microbe interactions in mosquitoes.

    

   more » « less
4. Bacterial communities in carnivorous pitcher plants colonize and persist in inquiline mosquitoes

   https://doi.org/10.1186/s42523-022-00164-1  

   Arellano, Aldo A. ; Coon, Kerri L. ( February 2022 , Animal Microbiome)

   The leaves of carnivorous pitcher plants harbor diverse communities of inquiline species, including bacteria and larvae of the pitcher plant mosquito (Wyeomyia smithii), which aid the plant by processing captured prey. Despite the growing appreciation for this microecosystem as a tractable model in which to study food web dynamics and the moniker ofW. smithiias a ‘keystone predator’, very little is known about microbiota acquisition and assembly inW. smithiimosquitoes or the impacts ofW. smithii-microbiota interactions on mosquito and/or plant fitness.

   In this study, we used high throughput sequencing of bacterial 16S rRNA gene amplicons to characterize and compare microbiota diversity in field- and laboratory-derivedW. smithiilarvae. We then conducted controlled experiments in the laboratory to better understand the factors shaping microbiota acquisition and persistence across theW. smithiilife cycle. Methods were also developed to produce axenic (microbiota-free)W. smithiilarvae that can be selectively recolonized with one or more known bacterial species in order to study microbiota function. Our results support a dominant role for the pitcher environment in shaping microbiota diversity inW. smithiilarvae, while also indicating that pitcher-associated microbiota can persist in and be dispersed by adultW. smithiimosquitoes. We also demonstrate the successful generation of axenicW. smithiilarvae and report variable fitness outcomes in gnotobiotic larvae monocolonized by individual bacterial isolates derived from naturally occurring pitchers in the field.

   This study provides the first information on microbiota acquisition and assembly inW. smithiimosquitoes. This study also provides the first evidence for successful microbiota manipulation in this species. Altogether, our results highlight the value of such methods for studying host-microbiota interactions and lay the foundation for future studies to understand howW. smithii-microbiota interactions shape the structure and stability of this important model ecosystem.

    

   more » « less
5. Assessing temperature‐dependent competition between two invasive mosquito species

   https://doi.org/10.1002/eap.2334  

   Evans, Michelle V. ; Drake, John M. ; Jones, Lindsey ; Murdock, Courtney C. ( April 2021 , Ecological Applications)

   Invasive mosquitoes are expanding their ranges into new geographic areas and interacting with resident mosquito species. Understanding how novel interactions can affect mosquito population dynamics is necessary to predict transmission risk at invasion fronts. Mosquito life‐history traits are extremely sensitive to temperature, and this can lead to temperature‐dependent competition between competing invasive mosquito species. We explored temperature‐dependent competition betweenAedes aegyptiandAnopheles stephensi, two invasive mosquito species whose distributions overlap in India, the Middle East, and North Africa, whereAn. stephensiis currently expanding into the endemic range ofAe. aegypti. We followed mosquito cohorts raised at different intraspecific and interspecific densities across five temperatures (16–32°C) to measure traits relevant for population growth and to estimate species’ per capita growth rates. We then used these growth rates to derive each species’ competitive ability at each temperature. We find strong evidence for asymmetric competition at all temperatures, withAe. aegyptiemerging as the dominant competitor. This was primarily because of differences in larval survival and development times across all temperatures that resulted in a higher estimated intrinsic growth rate and competitive tolerance estimate forAe. aegypticompared toAn. stephensi. The spread ofAn. stephensiinto the African continent could lead to urban transmission of malaria, an otherwise rural disease, increasing the human population at risk and complicating malaria elimination efforts. Competition has resulted in habitat segregation of other invasive mosquito species, and our results suggest that it may play a role in determining the distribution ofAn. stephensiacross its invasive range.

    

   more » « less