SREL Reprint #3592

Laboratory colonization by Dirofilaria immitis alters the microbiome of female Aedes aegypti mosquitoes

Abdulsalam Adegoke1, Erik Nef2,3, Amie Geary1, Montana Ciara Husser1, Kevin Wilson1,
Shawn Michael Norris1, Guha Dharmarajan2, and Shahid Karim1

1Center for Molecular and Cellular Biosciences, School of Biological, Environmental, and Earth Sciences,
The University of Southern Mississippi, Hattiesburg, MS 39406, USA
2Savannah River Ecology Laboratory, University of Georgia, P.O. Drawer E, Aiken, SC 29802, USA
3Warnell School of Forestry and Natural Resources, University of Georgia, Athens, GA 30602, USA

Abstract:
Background: The ability of blood-feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered with, or enhanced by, the arthropod’s native microbiome. Mosquitoes transmit viruses, protozoan and flarial nematodes, the majority of which contribute to the 17% of infectious disease cases worldwide. Diroflaria immitis, a mosquito-transmitted flarial nematodes of dogs and cats, is vectored by several mosquito species including Aedes aegypti.
Methods: In this study, we investigated the impact of D. immitis colonization on the microbiome of laboratory reared female Ae. aegypti. Metagenomic analysis of the V3–V4 variable region of the microbial 16S RNA gene was used for identifcation of the microbial diferences down to species level.
Results: We generated a total of 1068 OTUs representing 16 phyla, 181 genera and 271 bacterial species. Overall, in order of abundance, Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes were the most represented phylum with D. immitis-infected mosquitoes having more of Proteobacteria (71%) than uninfected mosquitoes (56.9%). An interesting fnding in this study is the detection of Klebsiella oxytoca in relatively similar abundance in infected and uninfected mosquitoes, suggesting a possible endosymbiotic relationship, and has been previously shown to indirectly compete for nutrients with fungi on domestic housefy eggs and larvae. While D. immitis colonization has no efect on the overall species richness, we identifed signifcant diferences in the composition of selected bacterial genera and phyla between the two groups. We also reported distinct compositional and phylogenetic diferences in the individual bacterial species when commonly identifed bacteria were compared.
Conclusions: To the best of our knowledge, this is the frst study to understand the impact of a flarial infection on the microbiome of its mosquito vector. Further studies are required to identify bacteria species that could play an important role in the mosquito biology. While the microbiome composition of Ae. aegypti mosquito have been previously reported, our study shows that in an efort to establish itself, a flarial nematode modifes and alters the overall microbial diversity within its mosquito host.

Keywords: Mosquitoes, Aedes aegypti, Microbiome, Metagenome, Diroflaria immitis, Dog heartworm

SREL Reprint #3592

Adegoke, A., E. Neff, A. Geary, M. C. Husser, K. Wilson, S. M. Norris, G. Dharmarajan, and S. Karim. 2020. Laboratory colonization by Dirofilaria immitis alters the microbiome of female Aedes aegypti mosquitoes. Parasites and Vectors 13(349): 1-13.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).