The Composition of Midgut Bacteria in<i>Aedes aegypti</i>(Diptera: Culicidae) That Are Naturally Susceptible or Refractory to Dengue Viruses

et al. 2020

Preprint

Background: The ability of blood feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered or enhanced by the arthropod’s native microbiome. Mosquitoes transmit bacteria, viruses, protozoan and filarial nematodes, majority of which contributes to the 17% of infectious disease cases worldwide. Dirofilaria immitis, a mosquito transmitted filarial 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 A. aegypti. Metagenomic analysis of the V3-V4 variable region of the microbial 16SRNA was used for identification of the microbial differences 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 finding in this study is the detection of Klebsiella oxytoca in relatively similar abundance in infected and uninfected mosquitoes. It has been previously shown to indirectly compete for nutrients with fungi on the domestic housefly eggs and larva. While not statistically significant, D. immitis infection alters bacterial diversity by reducing the bacterial species richness and abundance.Conclusions: In conclusion, this is the first study to the best of our knowledge to understand the impact of a filarial infection on the microbiome of its mosquito vector. While the microbiome composition of A. aegypti mosquito have been previously reported, our study shows that in an effort to establish itself, a filarial nematode modifies and alters the overall microbial diversity within its mosquito host.

Section: Discussionsupporting

confidence: 83%

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

et al. 2020

Preprint

“…This technique offers the advantage of detecting both culturable and unculturable pathogenic and non-pathogenic microbes from a given DNA or RNA sample. As previously reported from previous metagenome studies on mosquitoes and similar arthropods or insects [37,38,39], Figure 1A shows that the phylum Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes was detected from the mosquito groups tested. Similar studies have also identi ed the phylum Proteobacteria as one of the dominant phyla in the microbiome of A. aegypti mosquitoes [23,40].…”

Section: Discussionsupporting

confidence: 83%

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

et al. 2020

Preprint

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 filarial nematodes, the majority of which contribute to the 17% of infectious disease cases worldwide. Dirofilaria immitis, a mosquito transmitted by filarial 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 A. aegypti. Metagenomic analysis of the V3-V4 variable region of the microbial 16SRNA was used for identification of the microbial differences 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 finding 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 housefly eggs and larva. While D. immitis colonization has no effect on the overall species richness, we identified significant differences in the composition of selected bacteria genus and phylum between the two groups. We also reported distinct compositional and phylogenetic differences in the individual bacteria species when commonly identified bacteria were compared. Conclusions In conclusion, this is the first study to the best of our knowledge to understand the impact of a filarial 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 A. aegypti mosquito have been previously reported, our study shows that in an effort to establish itself, a filarial nematode modifies and alters the overall microbial diversity within its mosquito host.

“…This technique offers the advantage of detecting both culturable and unculturable pathogenic and non-pathogenic microbes from a given DNA or RNA. As previously reported from previous metagenome studies on mosquitoes and similar arthropods or insects (Mancini et al, 2018;Coon et al, 2014;Coatsworth et al, 2018), Figure 1A shows that the phylum Proteobacteria, Bacteroidetes, Actinobacteria and Firmicutes was detected from the mosquito groups tested. Similar studies have also identi ed the phylum Proteobacteria as one of the dominant phylum in the microbiome of A. aegypti mosquitoes (Ramirez et al, 2012;Audsley et al, 2017).…”

Section: Discussionsupporting

confidence: 83%

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

et al. 2020

Preprint

Background: The ability of blood feeding arthropods to successfully acquire and transmit pathogens of medical and veterinary importance has been shown to be interfered or enhanced by the arthropod’s native microbiome. Mosquitoes transmit bacteria, viruses, protozoan and filarial nematodes, majority of which contributes to the 17% of infectious disease cases worldwide. Dirofilaria immitis, a mosquito transmitted filarial 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 A. aegypti. Metagenomic analysis of the V3-V4 variable region of the microbial 16SRNA was used for identification of the microbial differences 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 finding in this study is the detection of Klebsiella oxytoca in relatively similar abundance in infected and uninfected mosquitoes, suggesting a possible endosymbiotic relationship. It has been previously shown to indirectly compete for nutrients with fungi on the domestic housefly eggs and larva. While D. immitis colonization has no effect on the overall species richness, we identified significant differences in the composition of selected bacteria genus and phylum between the two groups. We also reported distinct compositional and phylogenetic differences in the individual bacteria species when commonly identified bacteria were compared.Conclusions: In conclusion, this is the first study to the best of our knowledge to understand the impact of a filarial infection on the microbiome of its mosquito vector. Further studies is required to identify bacteria species that could play an important role in the mosquito biology. While the microbiome composition of A. aegypti mosquito have been previously reported, our study shows that in an effort to establish itself, a filarial nematode modifies and alters the overall microbial diversity within its mosquito host.