bioRxiv Science⌕ Search

bioRxiv · 10.1101/702464

Zika virus infection and temperature significantly impact Aedes albopictus gut microbiota

Abstract

Elizabethkingia anophelis has been the cause of four outbreaks with significant morbidity and mortality. Its transmission routes remain unknown and no point source of infection has been identified. Here we show that E. anophelis can be found in the saliva of Aedes mosquitoes, suggesting the novel possibility of vector-borne transmission of this bacterium. We additionally characterized diverse microbial communities in Aedes midguts, salivary glands and saliva. To the best of our knowledge, this represents the first description of the microbiome of Aedes saliva. Further, we demonstrate that increased abundance of E. anophelis is associated with decreased susceptibility and replication of Zika virus (ZIKV) in the midgut of Aedes mosquitoes, suggesting a novel transmission barrier for arboviruses transmitted by Aedes mosquitoes. Together, these results demonstrate the complex relationships between the mosquito, the midgut microbial community and arboviruses and offer insights into the epidemiology and control of emerging bacterial and viral pathogens. Author SummaryElizabethkingia anophelis has in the recent past caused outbreaks different parts of the world resulting both in morbidity and mortality. Until now, to the best of our knowledge, no study has been able to demonstrate that this bacterium can be transmitted by mosquitoes. We have demonstrated for the first time that Elizabethkingia anophelis is present in the saliva of both infected and non-infected Aedes mosquitoes. Further, we have shown that it confers an inhibitory effect on Zika virus establishment in the midguts of Aedes mosquitoes. Together, these results potentially display the potential for vector borne transmission of E. anophelis as well as a novel transmission barrier of ZIKV. Lastly, we have for the first time characterized salivary microbes of Aedes mosquitoes necessitating the investigation of the impact of salivary microbes in severity of disease in vertebrate hosts.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Onyango, M., Bialosuknia, S., Payne, A., Mathias, N., Kuo, L., Ciota, A., Kramer, L.. 2019-07-14. Zika virus infection and temperature significantly impact Aedes albopictus gut microbiota. https://doi.org/10.1101/702464

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Cell cycle progression and stalked cell morphogenesis in Caulobacter crescentus are regulated independently by the flagellum

Bacteria colonize surfaces and form biofilms to survive in stressful environmental conditions. Many bacteria use an appendage called the flagellum to sense surface contact, and responding to these mechanical cues triggers rapid physiological changes to promote downstream attachment. Bacteria are known to secrete adhesins and alter their motility behavior to facilitate surface colonization, but these changes alone are insufficient to explain the breadth of adaptations observed in surface-attached cells. Disrupting flagellar assembly in the bacterium Caulobacter crescentus constitutively activates the surface sensing pathway, and this gain-of-function phenotype was previously used to identify a suite of flagellar signaling suppressor (fss) genes that promotes surface adhesion downstream of the flagellum. We show herein that a subset of fss genes also regulates the C. crescentus developmental program. Live-cell microscopy analysis of fss mutants identified independent sub-pathways that target stalked cell morphogenesis and cell cycle progression. We identify the predicted chemotaxis genes fssD and fssE as novel regulators of stalked cell morphogenesis and show that these genes act to stimulate the diguanylate cyclase PleD in flagellar assembly mutants. A separate pathway that includes the stator protein MotB and the recently characterized dNTPase FssC regulates entry into S phase downstream of the flagellum. We show that motB regulates cell cycle progression specifically in response to surface cues, and that stator-dependent cell cycle control occurs independently of c-di-GMP and CtrA. This work clarifies the downstream targets of the surface sensing network and establishes a comprehensive model for how surface sensing influences the C. crescentus developmental program.

microbiology↗

Polyphyletic origins and lineage-specific expansion of chemosensory systems in phylum Actinomycetota

Phylum Actinomycetota (syn. Actinobacteriota or Actinobacteria), one of the largest well-studied bacterial phyla, is renowned for complex morphology, non-motility, ecological versatility, and secondary metabolite production. Chemosensory systems (CSS) are among the most sophisticated prokaryotic signal transduction architectures, yet their evolutionary distribution in this phylum remains poorly understood. Here, a comparative genomic analysis of 693 high-quality genomes spanning the phylum resolves the diversity, distribution, and evolutionary trajectories of CSS. Despite extensive genomic complexity and ecological versatility, only 6.9% of genomes encode complete CSS clusters, confined to a subset of lineages within a few classes, indicating lineage-specific retention or loss. In contrast, two-component systems (TCS) are ubiquitously abundant, with hybrid kinases enriched in CSS-deficient classes, suggesting functional compensation for the absence of dedicated chemosensory pathways. Basal lineages retain simplified CSS (F1 or F5), whereas Actinomycetes show lineage-specific expansion into multiple classes (F5, F8, F9, and ACF), often co-occurring, indicative of enhanced sensory complexity. The phylogeny of CheA homologs shows a polyphyletic distribution, supporting a mosaic evolutionary history shaped by multiple independent acquisitions, diversification, and gene loss. Collectively, our findings show that, unlike motile bacteria, members of Actinomycetota rely predominantly on TCS-driven regulatory networks, with CSS retained only in select lineages where ecological demands require enhanced environmental sensing. This work provides a phylum-wide evolutionary framework for the emergence, diversification, and functional specialization of CSS in non-motile bacteria.

microbiology↗

Seasonal H1N1 influenza A virus preferentially infects a pre-existing ciliogenesis-primed secretory cell state

Influenza A viruses (IAV) infect secretory and ciliated cells of the human airway epithelium , but whether all cells within one cell type are equally susceptible to infection remains unresolved. Here, single-cell RNA sequencing analysis of primary human bronchial epithelial cultures from three donors identified preferential infection of a transcriptionally distinct subpopulation of secretory cells by seasonal H1N1 IAV A/Hawaii/70/2019 . Genes upregulated in this subpopulation showed enrichment for cilium-related gene ontology terms. In an ex post facto approach, this enrichment persisted after excluding genes differentially expressed between infected and mock-treated samples, including those identified in secretory cell-specific comparisons. Single-cell analysis further revealed no significant increase in ciliogenesis scores in infected secretory cells compared to mock infected cells at 6 hours post-infection , arguing against infection-induced activation of the canonical ciliogenesis programme during the initial viral replication cycle . Collectively, these results support preferential infection of ciliogenesis-primed secretory cells and refine IAV tropism beyond cell type to encompass epithelial differentiation state.

microbiology↗