Wolbachia strain w AlbA blocks Zika virus transmission in Aedes aegypti

International audienceTransinfections of the maternally transmitted endosymbiont Wolbachia pip-ientis can reduce RNA virus replication and prevent transmission by Aedes aegypti, and also have the capacity to invade wild-type populations, potentially reaching and maintaining high infection frequencies. Levels of virus transmission blocking are positively correlated with Wolbachia intracellular density. Despite reaching high densities in Ae. aegypti, transinfections of wAlbA, a strain native to Aedes albopictus, showed no blocking of Semliki Forest Virus in previous intrathoracic injection challenges. To further characterize wAlbA blocking in Ae. aegypti, adult females were intrathoraci-cally challenged with Zika (ZIKV) and dengue viruses, and then fed a ZIKV-containing bloodmeal. No blocking was observed with either virus when challenged by intrathoracic injection. However, when ZIKV was delivered orally, wAlbA-infected females showed a significant reduction in viral replication and dissemination compared with uninfected controls, as well as a complete absence of virus in saliva. Although other Wolbachia strains have been shown to cause more robust viral blocking in Ae. aegypti, these findings demonstrate that, in principle, wAlbA could be used to reduce virus transmission in this species. Moreover, the results highlight the potential for underestimation of the strength of virus-blocking when based on intrathoracic injection compared with more natural oral challenges

The impact of the age of first blood meal and Zika virus infection on Aedes aegypti egg production and longevity

Submitted by Sandra Infurna ([email protected]) on 2019-02-13T12:13:10Z No. of bitstreams: 1 rafaelm_freitas_etal_IOC_2018.pdf: 3358923 bytes, checksum: 5137946e57a3481695a57867265452f4 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-02-13T12:26:40Z (GMT) No. of bitstreams: 1 rafaelm_freitas_etal_IOC_2018.pdf: 3358923 bytes, checksum: 5137946e57a3481695a57867265452f4 (MD5)Made available in DSpace on 2019-02-13T12:26:40Z (GMT). No. of bitstreams: 1 rafaelm_freitas_etal_IOC_2018.pdf: 3358923 bytes, checksum: 5137946e57a3481695a57867265452f4 (MD5) Previous issue date: 2018Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil / Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunologia Viral. Rio de Janeiro, RJ, Brasil.University of Antwerp. Laboratory for Microbiology, Parasitology and Hygiene. Antwerp, Belgium.University of Antwerp. Laboratory for Microbiology, Parasitology and Hygiene. Antwerp, Belgium.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Transmissores de Hematozoários. Rio de Janeiro, RJ, Brasil.The impact of senescence and pathogen infection on Aedes aegypti life-history traits remains poorly understood. This laboratory study focused on the impact of Zika virus (ZIKV) infection and the age of first blood intake on blood meal and clutch sizes, and more importantly on the egg production ratio per μL of blood. Three groups of ZIKV-infected and uninfected Ae. aegypti females that received their first blood meal at 7 (young feeders), 14 (mature feeders) and 21 days old (old feeders) were monitored daily for survival and received a blood meal free of ZIKV once a week. The number of eggs laid per female were registered 3-4 days after blood feeding. Infection by ZIKV and age of feeding produced a strong negative impact on survival and oviposition success (e.g. likelihood of laying at least one egg per gonotrophic cycle). Interestingly, clutch size presented a dramatic reduction on uninfected mosquitoes, but raised from 36.5 in clutch1 to 55.1 eggs in clutch 3. Blood meal size remained stable in uninfected females, while a slight increase was observed for the infected counterparts. In uninfected Ae. aegypti, egg production was strongly affected by the age of feeding with younger females laying three times more eggs than when older. On the other hand, ZIKV-infected mosquitoes had a constant but low egg production. Overall, mosquito senescence and ZIKV infection had an impact on mosquito egg production by causing a sharp decrease in the number of eggs along the clutches for uninfected mosquitoes and a slight increase for infected mosquitoes. Despite some study limitations, our results contribute to a better understanding of the effects of mosquito aging and pathogen infection on the vectorial capacity of Ae. aegypti

Rapid, noninvasive detection of Zika virus in Aedes aegypti mosquitoes by near-infrared spectroscopy

Submitted by Sandra Infurna ([email protected]) on 2018-08-02T11:05:58Z No. of bitstreams: 1 Lilha_santos_etal_IOC_2018.pdf: 554151 bytes, checksum: 91c0c589349f5e2126364e72724881df (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-08-02T11:18:06Z (GMT) No. of bitstreams: 1 Lilha_santos_etal_IOC_2018.pdf: 554151 bytes, checksum: 91c0c589349f5e2126364e72724881df (MD5)Made available in DSpace on 2018-08-02T11:18:06Z (GMT). No. of bitstreams: 1 Lilha_santos_etal_IOC_2018.pdf: 554151 bytes, checksum: 91c0c589349f5e2126364e72724881df (MD5) Previous issue date: 2018University of Queensland. Queensland Alliance for Agriculture and Food Innovation. St. Lucia, Queensland, Australia.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil.University of Miami Miller School of Medicine. Department of Public Health Services. Miami, FL, USA.U.S. Department of Agriculture. Agricultural Research Service. Center for Grain and Animal Health Research. Manhatta, USA / University of Miami Miller School of Medicine. Department of Publica Health. Miami, FL, USA.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Mosquitos Transmissores de Hematozoários. Rio de Janeiro, RJ. Brasil / Universidade Federal do Rio de Janeiro. Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular. Rio de Janeiro, RJ, Brasil.University of Queensland. Queensland Alliance for Agriculture and Food Innovation. St. Lucia, Queensland, Australia.The accelerating global spread of arboviruses, such as Zika virus (ZIKV), highlights the need for more proactive mosquito surveillance. However, amajor challenge during arbovirus outbreaks has been the lack of rapid and affordable tests for pathogen detection inmosquitoes. We show for the first time that near-infrared spectroscopy (NIRS) is a rapid, reagent-free, and cost-effective tool that can be used to noninvasively detect ZIKV in heads and thoraces of intact Aedes aegypti mosquitoes with prediction accuracies of 94.2 to 99.3% relative to quantitative reverse transcription polymerase chain reaction (RT-qPCR). NIRS involves simply shining a beam of light on a mosquito to collect a diagnostic spectrum. We estimated in this study that NIRS is 18 times faster and 110 times cheaper than RT-qPCR. We anticipate that NIRS will be expanded upon for identifying potential arbovirus hotspots to guide the spatial prioritization of vector control

Rapid, noninvasive detection of Zika virus in mosquitoes by near-infrared spectroscopy

The accelerating global spread of arboviruses, such as Zika virus (ZIKV), highlights the need for more proactive mosquito surveillance. However, a major challenge during arbovirus outbreaks has been the lack of rapid and affordable tests for pathogen detection in mosquitoes. We show for the first time that near-infrared spectroscopy (NIRS) is a rapid, reagent-free, and cost-effective tool that can be used to noninvasively detect ZIKV in heads and thoraces of intact mosquitoes with prediction accuracies of 94.2 to 99.3% relative to quantitative reverse transcription polymerase chain reaction (RT-qPCR). NIRS involves simply shining a beam of light on a mosquito to collect a diagnostic spectrum. We estimated in this study that NIRS is 18 times faster and 110 times cheaper than RT-qPCR. We anticipate that NIRS will be expanded upon for identifying potential arbovirus hotspots to guide the spatial prioritization of vector control