scholarly journals Reduced competence to arboviruses following the sustainable invasion of Wolbachia into native Aedes aegypti from Southeastern Brazil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
João Silveira Moledo Gesto ◽  
Gabriel Sylvestre Ribeiro ◽  
Marcele Neves Rocha ◽  
Fernando Braga Stehling Dias ◽  
Julia Peixoto ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Oral Feeding ◽  
Southeastern Brazil ◽  
Proof Of Concept ◽  
Small Community ◽  
High Infection ◽  
Promising Solution ◽  
Virus Blocking

AbstractField release of Wolbachia-infected Aedes aegypti has emerged as a promising solution to manage the transmission of dengue, Zika and chikungunya in endemic areas across the globe. Through an efficient self-dispersing mechanism, and the ability to induce virus-blocking properties, Wolbachia offers an unmatched potential to gradually modify wild Ae. aegypti populations turning them unsuitable disease vectors. Here we describe a proof-of-concept field trial carried out in a small community of Niterói, greater Rio de Janeiro, Brazil. Following the release of Wolbachia-infected eggs, we report here a successful invasion and long-term establishment of the bacterium across the territory, as denoted by stable high-infection indexes (> 80%). We have also demonstrated that refractoriness to dengue and Zika viruses, either thorough oral-feeding or intra-thoracic saliva challenging assays, was maintained over the adaptation to the natural environment of Southeastern Brazil. These findings further support Wolbachia’s ability to invade local Ae. aegypti populations and impair disease transmission, and will pave the way for future epidemiological and economic impact assessments.

scholarly journals Reduced competence to arboviruses following the sustainable invasion of Wolbachia into native Aedes aegypti from Niterói, Southeastern Brazil

2020 ◽  
Author(s):  
João Silveira Moledo Gesto ◽  
Gabriel Sylvestre Ribeiro ◽  
Marcele Neves Rocha ◽  
Fernando Braga Stehling Dias ◽  
Julia Peixoto ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Oral Feeding ◽  
Southeastern Brazil ◽  
Proof Of Concept ◽  
Small Community ◽  
High Infection ◽  
Promising Solution ◽  
Virus Blocking

AbstractField release of Wolbachia-infected Aedes aegypti has emerged as a promising solution to manage the transmission of dengue, Zika and chikungunya in endemic areas across the globe. Through an efficient self-dispersing mechanism, and the ability to induce virus-blocking properties, Wolbachia offers an unmatched potential to gradually modify wild Ae. aegypti populations turning them unsuitable disease vectors. Here in this work, a proof-of-concept field trial was carried out in a small community of Niterói, greater Rio de Janeiro. Following the release of Wolbachia-infected eggs, we reported a successful invasion and long-term establishment of the bacterium across the territory, as denoted by stable high-infection indexes (>80%). We have also demonstrated that refractoriness to dengue and Zika viruses, either thorough oral-feeding or intra-thoracic saliva challenging assays, were maintained over the adaptation to the natural environment of Southeastern Brazil. These findings further support Wolbachia’s ability to invade local Ae. aegypti populations and impair disease transmission, and shall pave the way for future epidemiological and economic impact assessments.

scholarly journals Large-Scale Deployment and Establishment of Wolbachia Into the Aedes aegypti Population in Rio de Janeiro, Brazil

2021 ◽  
Vol 12 ◽  
Author(s):  
João Silveira Moledo Gesto ◽  
Sofia B. Pinto ◽  
Fernando Braga Stehling Dias ◽  
Julia Peixoto ◽  
Guilherme Costa ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Vector Control ◽  
Disease Transmission ◽  
Rio De Janeiro ◽  
Large Scale ◽  
Southeastern Brazil ◽  
Infection Rates ◽  
Residential Areas ◽  
Dispersing Agent ◽  
Vector Control Intervention

Traditional methods of vector control have proven insufficient to reduce the alarming incidence of dengue, Zika, and chikungunya in endemic countries. The bacterium symbiont Wolbachia has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of Aedes aegypti populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale Wolbachia intervention in Ilha do Governador, Rio de Janeiro, Brazil. wMel-infected adults were released across residential areas between August 2017 and March 2020. Over 131 weeks, including release and post-release phases, we monitored the wMel prevalence in field specimens and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that wMel successfully invaded both areas, reaching overall infection rates of 50–70% in RJ1 and 30–60% in RJ2 by the end of the monitoring period. At the neighborhood-level, wMel introgression was heterogeneous in both RJ1 and RJ2, with some profiles sustaining a consistent increase in infection rates and others failing to elicit the same. Correlation analysis revealed a weak overall association between RJ1 and RJ2 (r = 0.2849, p = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (r = 0.4676, p < 0.0001) or RJ2 (r = 0.6263, p < 0.0001). The frequency knockdown resistance (kdr) alleles in wMel-infected specimens from both areas were consistently high over this study. Altogether, these findings corroborate that wMel can be successfully deployed at large-scale as part of vector control intervention strategies and provide the basis for imminent disease impact studies in Southeastern Brazil.

scholarly journals Genetic stability of Aedes aegypti populations following invasion by wMel Wolbachia

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Meng-Jia Lau ◽  
Thomas L. Schmidt ◽  
Qiong Yang ◽  
Jessica Chung ◽  
Lucien Sankey ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Geographic Location ◽  
Infection Status ◽  
Population Differences ◽  
Outlier Analysis ◽  
Genetic Changes ◽  
Genome Wide ◽  
And Behavior

Abstract Background Wolbachia wMel is the most commonly used strain in rear and release strategies for Aedes aegypti mosquitoes that aim to inhibit the transmission of arboviruses such as dengue, Zika, Chikungunya and yellow fever. However, the long-term establishment of wMel in natural Ae. aegypti populations raises concerns that interactions between Wolbachia wMel and Ae. aegypti may lead to changes in the host genome, which could affect useful attributes of Wolbachia that allow it to invade and suppress disease transmission. Results We applied an evolve-and-resequence approach to study genome-wide genetic changes in Ae. aegypti from the Cairns region, Australia, where Wolbachia wMel was first introduced more than 10 years ago. Mosquito samples were collected at three different time points in Gordonvale, Australia, covering the phase before (2010) and after (2013 and 2018) Wolbachia releases. An additional three locations where Wolbachia replacement happened at different times across the last decade were also sampled in 2018. We found that the genomes of mosquito populations mostly remained stable after Wolbachia release, with population differences tending to reflect the geographic location of the populations rather than Wolbachia infection status. However, outlier analysis suggests that Wolbachia may have had an influence on some genes related to immune response, development, recognition and behavior. Conclusions Ae. aegypti populations remained geographically distinct after Wolbachia wMel releases in North Australia despite their Wolbachia infection status. At some specific genomic loci, we found signs of selection associated with Wolbachia, suggesting potential evolutionary impacts can happen in the future and further monitoring is warranted.

scholarly journals Large-scale deployment and establishment of Wolbachia into the Aedes aegypti population in Rio de Janeiro, Brazil.

2021 ◽  
Author(s):  
Joao Silveira Moledo Gesto ◽  
Sofia Pinto ◽  
Fernando Braga Stehling Dias ◽  
Julia Peixoto ◽  
Guilherme Costa ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Vector Control ◽  
Disease Transmission ◽  
Rio De Janeiro ◽  
Large Scale ◽  
Southeastern Brazil ◽  
Infection Rates ◽  
Residential Areas ◽  
Dispersing Agent ◽  
Vector Control Intervention

Traditional methods of vector control have proven insufficient to reduce the alarming incidence of Dengue, Zika and chikungunya in endemic countries. The bacterium symbiont Wolbachia has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of Aedes aegypti populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale Wolbachia intervention in Ilha do Governador, Rio de Janeiro, Brazil. wMel-infected adults were released across residential areas between August 2017 and March 2020. Over 131 weeks, including release and post-release phases, we monitored the wMel prevalence in field specimens, and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that wMel successfully invaded both areas, reaching overall infection rates of 50-70% in RJ1, and 30-60% in RJ2 by the end of the monitoring period. At the neighborhood-level, wMel introgression was heterogeneous in both RJ1 and RJ2, with some profiles sustaining a consistent increase in infection rates and others failing to elicit the same. Correlation analysis revealed a weak overall association between RJ1 and RJ2 (r = 0.2849, P = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (r = 0.4676, P < 0.0001) or RJ2 (r = 0.6263, P < 0.0001). The frequency knockdown resistance (kdr) alleles in wMel-infected specimens from both areas was consistently high over this study. Altogether, these findings corroborate that wMel can be successfully deployed at large-scale as part of vector control intervention strategies, and provide the basis for imminent disease impact studies in Southeastern Brazil.

scholarly journals Persistent deleterious effects of an unstable deleterious Wolbachia infection

2019 ◽  
Author(s):  
Perran A. Ross ◽  
Jason K. Axford ◽  
Ashley G. Callahan ◽  
Kelly M. Richardson ◽  
Ary A. Hoffmann
Keyword(s):  
Aedes Aegypti ◽  
Natural Populations ◽  
Wolbachia Infection ◽  
Phenotypic Analysis ◽  
Fitness Effects ◽  
Dengue Transmission ◽  
Evolutionary Changes ◽  
Laboratory Colonies ◽  
Virus Blocking

AbstractWolbachia are being used to reduce dengue transmission by Aedes aegypti mosquitoes around the world. To date releases have mostly involved Wolbachia strains with limited fitness effects but strains with larger fitness costs could be used to suppress mosquito populations. However, such infections are expected to evolve towards decreased deleterious effects. Here we investigate potential evolutionary changes in the wMelPop infection transferred from Drosophila melanogaster to Aedes aegypti more than ten years (~120 generations) ago. We show that most deleterious effects of this infection have persisted despite strong selection to ameliorate them. The wMelPop infection is difficult to maintain in laboratory colonies, likely due to the persistent deleterious effects coupled with occasional maternal transmission leakage. Furthermore, female mosquitoes can be scored incorrectly as infected due to transmission of Wolbachia through mating. Infection loss in colonies was not associated with evolutionary changes in the nuclear background. These findings suggest that Wolbachia transinfections with deleterious effects may have stable phenotypes which could ensure their long-term effectiveness if released in natural populations to reduce population size.Author summaryMosquitoes infected with Wolbachia bacteria are being deployed into the field where they can suppress mosquito populations and reduce dengue transmission. These programs rely on the use of Wolbachia strains that have desirable phenotypes, which can include deleterious fitness effects, reproductive manipulation and virus blocking. However, theory predicts that Wolbachia will evolve to become less costly to their hosts, reducing the effectiveness of these programs. We investigate the potential for evolutionary changes by performing a comprehensive phenotypic analysis of a deleterious Wolbachia strain, wMelPop, that was introduced to Aedes aegypti mosquitoes from Drosophila over ten years ago. In contrast to theoretical expectations and research from Drosophila, our results suggest that Wolbachia strains with deleterious effects may have stable phenotypes, ensuring their long-term effectiveness if released into natural populations.

scholarly journals Genetic Stability of Aedes aegypti Populations following Invasion by wMel Wolbachia

2021 ◽  
Author(s):  
Meng-Jia Lau ◽  
Tom Schmidt ◽  
Qiong Yang ◽  
Jessica Chung ◽  
Lucien Sankey ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Natural Populations ◽  
Geographic Location ◽  
Infection Status ◽  
Outlier Analysis ◽  
Genetic Changes ◽  
Genome Wide ◽  
And Behavior

Abstract BackgroundWolbachia wMel is the most used strain in mosquito rear and release strategies that aim to inhibit the transmission of arboviruses such as dengue, Zika, Chikungunya and yellow fever. However, the long-term establishment of wMel in natural populations of the dengue mosquito Aedes aegypti raises concerns that interactions between Wolbachia wMel and Ae. aegypti may lead to changes in the host genome, which could affect useful attributes of Wolbachia that allow it to invade and suppress disease transmission. ResultsWe applied an evolve-and-resequence approach to study genome-wide genetic changes in Ae. aegypti from the Cairns region, Australia, where Wolbachia wMel was first introduced more than 10 years ago. Mosquito samples were collected at three different time points in Gordonvale, Australia, covering the phase before (2010) and after (2013 and 2018) Wolbachia releases. An additional three locations where Wolbachia replacement happened at different times across the last decade were also sampled in 2018. We found that the genomes of mosquito populations mostly remained stable after Wolbachia release, with population differences tending to reflect the geographic location of the populations rather than Wolbachia infection status. However, outlier analysis suggests that Wolbachia may have had an influence on some genes related to immune response, development, recognition and behavior. ConclusionsAe. aegypti populations remained geographically distinct after Wolbachia wMel releases in North Australia despite their Wolbachia infection status. At some specific genomic loci, we found signs of selection associated with Wolbachia, suggesting potential evolutionary impacts can happen in the future and further monitoring is warranted.

scholarly journals Genetic stability of Aedes aegypti populations following invasion by wMel Wolbachia

2021 ◽  
Author(s):  
Meng-Jia Lau ◽  
Tom Schmidt ◽  
Qiong Yang ◽  
Jessica Chung ◽  
Ary A. Hoffmann
Keyword(s):  
Aedes Aegypti ◽  
Disease Transmission ◽  
Natural Populations ◽  
Geographic Location ◽  
Infection Status ◽  
Population Differences ◽  
Outlier Analysis ◽  
Genetic Changes ◽  
Genome Wide

Background: Wolbachia wMel play a major role in mosquito rear and release strategies that aim to inhibit the transmission of arboviruses such as dengue, Zika, Chikungunya and yellow fever. However, the long-term establishment of wMel in natural populations of the dengue mosquito Aedes aegypti raises concerns that interactions between Wolbachia wMel and Ae. aegypti may lead to changes in the host genome, which could affect useful attributes of Wolbachia that allow it to invade and suppress disease transmission. Results: We applied an evolve-and-resequence approach to study genome-wide genetic changes in Ae. aegypti from the Cairns region, Australia, where Wolbachia wMel was first introduced more than 10 years ago. Mosquito samples were collected at three different time points in Gordonvale, Australia, covering the phase before (2010) and after (2013 and 2018) Wolbachia releases; an additional three locations where Wolbachia replacement happened at different times across the last decade were also sampled in 2018. We found that in general, the genome of mosquito populations mostly remained stable after Wolbachia release, with any population differences tending to reflect the geographic location of the populations rather than Wolbachia infection status. Whereas on the other hand, outlier analysis suggested that Wolbachia may have had an influence on some genes related to immune response, development, recognition and behaviour. Conclusions: In general, Ae. aegypti populations remained geographically distinct after Wolbachia releases in North Australia despite their Wolbachia infection status. Whereas at some specific genomic loci, we found signs of selection associated with Wolbachia, suggesting potential evolutionary impacts can happen in the future and further monitoring is warranted.

Periodic monitoring of vampire bats and rabies: a new framework for animal restoration projects in the Neotropics

2020 ◽  
Author(s):  
Fernando Gonçalves ◽  
Daniel G. Streicker ◽  
Mauro Galetti
Keyword(s):  
Disease Transmission ◽  
Lessons Learned ◽  
Multidisciplinary Teams ◽  
Risk Area ◽  
Food Web Structure ◽  
Land Bridge ◽  
High Risk Area ◽  
Restoration Project ◽  
Vampire Bats

Nowadays, restoration project might lead to increased public engagement and enthusiasm for biodiversity and is receiving increased media attention in major newspapers, TED talks and the scientific literature. However, empirical research on restoration project is rare, fragmented, and geographically biased and long-term studies that monitor indirect and unexpected effects are needed to support future management decisions especially in the Neotropical area. Changes in animal population dynamics and community composition following species (re)introduction may have unanticipated consequences for a variety of downstream ecosystem processes, including food web structure, predator-prey systems and infectious disease transmission. Recently, an unprecedented study in Brazil showed changes in vampire bat feeding following a rewilding project and further transformed the land-bridge island into a high-risk area for rabies transmission. Due the lessons learned from ongoing project, we present a novel approach on how to anticipate, monitor, and mitigate the vampire bats and rabies in rewilding projects. We pinpoint a series of precautions and the need for long-term monitoring of vampire bats and rabies responses to rewilding projects and highlighted the importance of multidisciplinary teams of scientist and managers focusing on prevention educational program of rabies risk transmitted by bats. In addition, monitoring the relative abundance of vampire bats, considering reproductive control by sterilization and oral vaccines that autonomously transfer among bats would reduce the probability, size and duration of rabies outbreaks. The rewilding assessment framework presented here responds to calls to better integrate the science and practice of rewilding and also could be used for long-term studying of bat-transmitted pathogen in the Neotropical area as the region is considered a geographic hotspots of “missing bat zoonoses”.

scholarly journals Proceedings of the First Curing Coma Campaign NIH Symposium: Challenging the Future of Research for Coma and Disorders of Consciousness

2021 ◽  
Vol 35 (S1) ◽  
pp. 4-23
Author(s):  
Jan Claassen ◽  
Yama Akbari ◽  
Sheila Alexander ◽  
Mary Kay Bader ◽  
Kathleen Bell ◽  
...  
Keyword(s):  
Neurocritical Care ◽  
Panel Discussion ◽  
Large Datasets ◽  
Disorders Of Consciousness ◽  
National Institutes Of Health ◽  
Proof Of Concept ◽  
Research Gaps ◽  
Main Research ◽  
The World

AbstractComa and disorders of consciousness (DoC) are highly prevalent and constitute a burden for patients, families, and society worldwide. As part of the Curing Coma Campaign, the Neurocritical Care Society partnered with the National Institutes of Health to organize a symposium bringing together experts from all over the world to develop research targets for DoC. The conference was structured along six domains: (1) defining endotype/phenotypes, (2) biomarkers, (3) proof-of-concept clinical trials, (4) neuroprognostication, (5) long-term recovery, and (6) large datasets. This proceedings paper presents actionable research targets based on the presentations and discussions that occurred at the conference. We summarize the background, main research gaps, overall goals, the panel discussion of the approach, limitations and challenges, and deliverables that were identified.

scholarly journals Parenteral Nutrition and Oxidant Load in Neonates

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2631
Author(s):  
Kandeepan Karthigesu ◽  
Robert F. Bertolo ◽  
Robert J. Brown
Keyword(s):  
Parenteral Nutrition ◽  
Storage Temperature ◽  
Oral Feeding ◽  
Published Data ◽  
Short Term ◽  
Antioxidant Defences ◽  
Term Survival ◽  
Nutrient Sources ◽  
Short Term Survival

Neonates with preterm, gastrointestinal dysfunction and very low birth weights are often intolerant to oral feeding. In such infants, the provision of nutrients via parenteral nutrition (PN) becomes necessary for short-term survival, as well as long-term health. However, the elemental nutrients in PN can be a major source of oxidants due to interactions between nutrients, imbalances of anti- and pro-oxidants, and environmental conditions. Moreover, neonates fed PN are at greater risk of oxidative stress, not only from dietary sources, but also because of immature antioxidant defences. Various interventions can lower the oxidant load in PN, including the supplementation of PN with antioxidant vitamins, glutathione, additional arginine and additional cysteine; reduced levels of pro-oxidant nutrients such as iron; protection from light and oxygen; and proper storage temperature. This narrative review of published data provides insight to oxidant molecules generated in PN, nutrient sources of oxidants, and measures to minimize oxidant levels.

Sign in / Sign up

Export Citation Format

Share Document