Dataset Information

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

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.

SUBMITTER: Ekwudu O

PROVIDER: S-EPMC7460537 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

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

Ekwudu O'mezie O Marquart Louise L Webb Lachlan L Lowry Kym S KS Devine Gregor J GJ Hugo Leon E LE Frentiu Francesca D FD

Pathogens (Basel, Switzerland) 20200818 8

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, <i>Aedes aegypti</i> and <i>Ae. albopictus</i> ...[more]

PMID: 32824792

Similar Datasets

Project description:Intrahost genetic diversity is thought to facilitate arbovirus adaptation to changing environments and hosts, and it might also be linked to viral pathogenesis. Dengue virus serotype 2 (DENV-2) has circulated in Brazil since 1990 and is associated with severe disease and explosive outbreaks. Intending to shed light on the viral determinants for severe dengue pathogenesis, we sought to analyze the DENV-2 intrahost genetic diversity in 68 patient cases clinically classified as dengue fever (n = 31), dengue with warning signs (n = 19), and severe dengue (n = 18). Unlike previous DENV intrahost diversity studies whose approaches employed PCR, here we performed viral whole-genome deep sequencing from clinical samples with an amplicon-free approach, representing the real intrahost diversity scenario. Striking differences were detected in the viral population structure between the three clinical categories, which appear to be driven mainly by different infection times and selection pressures, rather than being linked with the clinical outcome itself. Diversity in the NS2B gene, however, showed to be constrained, irrespective of clinical outcome and infection time. Finally, 385 non-synonymous intrahost single-nucleotide variants located along the viral polyprotein, plus variants located in the untranslated regions, were consistently identified among the samples. Of them, 124 were exclusively or highly detected among cases with warning signs and among severe cases. However, there was no variant that by itself appeared to characterize the cases of greater severity, either due to its low intrahost frequency or the conservative effect on amino acid substitution. Although further studies are necessary to determine their real effect on viral proteins, this heightens the possibility of epistatic interactions. The present analysis represents an initial effort to correlate DENV-2 genetic diversity to its pathogenic potential and thus contribute to understanding the virus's dynamics within its human host.

Project description:IntroductionThe first outbreak of dengue in American Samoa was reported in 1911. Sporadic outbreaks have been reported since, as were outbreaks of other pathogens transmitted by Aedes species mosquitoes including Ross River, chikungunya, and Zika viruses. During an outbreak of dengue virus-type 2 (DENV-2) in 2016-2018, we conducted household-based cluster investigations to identify population-specific risk factors associated with infection and performed entomologic surveillance to determine the relative abundance of Ae. aegypti and Ae. polynesiensis.Methods and findingsWe contacted dengue patients who had tested positive for DENV infection and offered them as well as their household members participation in household-based cluster investigations. For those that accepted participation, we also offered participation to residents of households within a 50-meter radius of each case-patient's home. Questionnaires were administered and serum specimens collected for testing by RT-PCR and anti-DENV IgM ELISA. Adult female mosquitoes were aspirated from inside and outside participating households and tested by RT-PCR. We analyzed characteristics associated with DENV infection in bivariate analyses. A total of 226 participants was enrolled from 91 households in 20 clusters. Median age of participants was 34 years (range: <1-94), and 56.2% were female. In total, 7 (3.2%) participants had evidence of DENV infection by IgM ELISA (n = 5) or RT-PCR (n = 2). Factors significantly associated with DENV infection were reporting a febrile illness in the past three months (prevalence ratio: 7.5 [95% confidence interval: 1.9-29.8]) and having a household septic tank (Fisher's Exact Test, p = 0.004). Of 93 Ae. aegypti and 90 Ae. polynesiensis females collected, 90% of Ae. aegypti were collected inside homes whereas 83% of Ae. polynesiensis were collected outside homes. DENV nucleic acid was not detected in any mosquito pools. Sequencing of the DENV-2 from patient specimens identified the Cosmopolitan genotype of DENV-2 and was most closely related to virus detected in the Solomon Islands during 2016.ConclusionsThis investigation demonstrated that dengue is a continuing risk in American Samoa. Increased frequency of infection among residents with a septic tank suggests a need to investigate whether septic tanks serve as larval habitats for mosquito vectors of DENV in American Samoa. Future efforts should also evaluate the role of Ae. polynesiensis in DENV transmission in the wild.

Dataset Information

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

Publications

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

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets