Culex pipiens and Culex restuans egg rafts harbor diverse bacterial communities compared to their midgut tissues

Authors: JUMA, ELIJAH - University Of Illinois; KIM, CHANG-HYUN - University Of Illinois; Dunlap, Christopher; ALLAN, BRIAN - University Of Illinois; STONE, CHRISTOPHER - University Of Illinois

Submitted to: Parasites & Vectors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2020
Publication Date: 10/27/2020
Citation: Juma, E.O., Kim, C., Dunlap, C.A., Allan, B.F., Stone, C. 2020. Culex pipiens and Culex restuans egg rafts harbor diverse bacterial communities compared to their midgut tissues. Parasites & Vectors. 13. Article 532. https://doi.org/10.1186/s13071-020-04408-4.
DOI: https://doi.org/10.1186/s13071-020-04408-4

Interpretive Summary: An ARS researcher from Peoria, IL collaborated with scientists from University Illinois to characterize the microbes colonizing the eggs of important mosquito species in the Midwest region of the United States. Mosquito egg microbial communities play a critical role in mosquito ecology and have been shown to mediate egg hatch. This manuscript reports on egg microbial communities of two important mosquito species in the Midwest region of the United States. The results provide a basis for understanding the role of mosquito egg-associated microbial communities in mosquito biology and mosquito-borne disease control. This research benefits mosquito researchers and citizens of the Midwest impacted by mosquito vectored diseases.

Technical Abstract: Background The bacterial communities associated with mosquito eggs are an essential component of the mosquito microbiota, yet there are few studies characterizing and comparing the microbiota of mosquito eggs to other host tissues. Methods We sampled gravid female Culex pipiens L. and Culex restuans Theobald from the field, allowed them to oviposit in the laboratory, and characterized the bacterial communities associated with their egg rafts and midguts for comparison through MiSeq sequencing of the 16S rRNA gene. Results Bacterial richness was higher in egg rafts than in midguts for both species, and higher in Cx pipiens than Cx. restuans. The midgut samples of Cx. pipiens and Cx. restuans were dominated by Providencia. Culex pipiens and Cx. restuans egg rafts samples were dominated by Ralstonia and Novosphingobium, respectively. NMDS ordination based on Bray-Curtis distance matrix revealed that egg-raft samples, or midgut tissues harbored similar bacterial communities regardless of the mosquito species. Within each mosquito species, there was a distinct clustering of bacterial communities between egg raft and midgut tissues. Conclusion These findings expand the list of described bacterial communities associated with Cx. pipiens and Cx. restuans and the additional characterization of the egg raft bacterial communities facilitates comparative analysis of mosquito host tissues, providing a basis for future studies seeking to understand any functional role of the bacterial communities in mosquito biology.