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. 2020 Aug 18;9(8):668.
doi: 10.3390/pathogens9080668.

Effect of Serotype and Strain Diversity on Dengue Virus Replication in Australian Mosquito Vectors

O'mezie Ekwudu  1   2   3 , Louise Marquart  4   5 , Lachlan Webb  4 , Kym S Lowry  1 , Gregor J Devine  2 , Leon E Hugo  2 , Francesca D Frentiu  1
Affiliations

Effect of Serotype and Strain Diversity on Dengue Virus Replication in Australian Mosquito Vectors

O'mezie Ekwudu et al. Pathogens. .

Abstract

Dengue virus (DENV) is the most important mosquito-borne viral pathogen of humans, comprising four serotypes (DENV-1 to -4) with a myriad of genotypes and strains. The kinetics of DENV replication within the mosquito following ingestion of a blood meal influence the pathogen's ability to reach the salivary glands and thus the transmission potential. The influence of DENV serotype and strain diversity on virus kinetics in the two main vector species, Aedes aegypti and Ae. albopictus, has been poorly characterized. We tested whether DENV replication kinetics vary systematically among serotypes and strains, using Australian strains of the two vectors. Mosquitoes were blood fed with two strains per serotype, and sampled at 3, 6, 10 and 14-days post-exposure. Virus infection in mosquito bodies, and dissemination of virus to legs and wings, was detected using qRT-PCR. For both vectors, we found significant differences among serotypes in proportions of mosquitoes infected, with higher numbers for DENV-1 and -2 versus other serotypes. Consistent with this, we observed that DENV-1 and -2 generally replicated to higher RNA levels than other serotypes, particularly at earlier time points. There were no significant differences in either speed of infection or dissemination between the mosquito species. Our results suggest that DENV diversity may have important epidemiological consequences by influencing virus kinetics in mosquito vectors.

Keywords: Aedes aegypti; Aedes albopictus; arbovirus; dengue viruses (DENV); flavivirus; genetic diversity; vector competence; virus kinetics.

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Conflict of interest statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results

Figures

Figure 1
Figure 1
Growth kinetics of dengue virus strains from all four serotypes within Ae. aegypti mosquitoes. Virus loads in (a) bodies and (b) legs and wings. Points show the number of virus copies in individual samples. Lines indicate means. nt, not tested (mosquitoes infected with DENV-1 ET-243 did not survive to 14 dpe). LOD, limit of detection.
Figure 2
Figure 2
Growth kinetics of dengue virus strains from all four serotypes within Ae. albopictus mosquitoes. Virus loads in (a). bodies and (b). legs and wings. Points show the number of virus copies in individual samples. Lines indicate means. LOD, limit of detection.
Figure 3
Figure 3
Magnitude of differences from Tukey’s pairwise difference test for each pair of dengue strain and pair of days post DENV exposure (Days). Direction of difference in reference to Y axis (vertical) minus X axis (horizontal). (A) Pairwise comparisons among Dengue strains in Bodies, (B) Pairwise comparisons among Days in Bodies, (C) Pairwise comparisons among Dengue strains in Legs/Wings, (D) Pairwise comparisons among Days in Legs/Wings. *, p < 0.05. **, p < 0.01. ***, p < 0.001.
See this image and copyright information in PMC

References

    1. Gubler D.J. Dengue, urbanization and globalization: The unholy trinity of the 21(st) century. Trop. Med. Health. 2011;39(Suppl. 4):3–11. doi: 10.2149/tmh.2011-S05. - DOI - PMC - PubMed
    1. Hare F.E. The 1897 epidemic of dengue in north Queensland. Aust. Med. Gaz. 1898;17:98–107.
    1. Hanna J.N., Ritchie S.A. An apparent recent decline in importations of dengue from Papua New Guinea into north Queensland. Commun. Dis. Intell. Q. Rep. 2009;33:34–35. - PubMed
    1. Warrilow D., Northill J.A., Pyke A.T. Sources of dengue viruses imported into Queensland, Australia, 2002–2010. Emerg. Infect. Dis. 2012;18:1850–1857. doi: 10.3201/eid1811.120014. - DOI - PMC - PubMed
    1. Viennet E., Ritchie S.A., Faddy H.M., Williams C.R., Harley D. Epidemiology of dengue in a high-income country: A case study in Queensland, Australia. Parasites Vectors. 2014;7:379. doi: 10.1186/1756-3305-7-379. - DOI - PMC - PubMed

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