scholarly journals Wolbachia pipientis occurs in Aedes aegypti populations in New Mexico and Florida, USA

2018 ◽  
Author(s):  
Aditi Kulkarni ◽  
Wanqin Yu ◽  
Jinjin Jiang ◽  
Concepcion Sanchez ◽  
Ajit K. Karna ◽  
...  
Keyword(s):  
New Mexico ◽  
Aedes Aegypti ◽  
Control Strategies ◽  
Vector Competence ◽  
Virus Transmission ◽  
Lamp Assay ◽  
Harris County ◽  
Pcr Assay ◽  
Wolbachia Pipientis ◽  
Pcr Products

ABSTRACTThe mosquitoes Aedes aegypti (L.) and Ae. albopictus Skuse are the major vectors of dengue, Zika, yellow fever and chikungunya viruses worldwide. Wolbachia, an endosymbiotic bacterium present in many insects, is being utilized in novel vector control strategies to manipulate mosquito life history and vector competence to curb virus transmission. Earlier studies have found that Wolbachia is commonly detected in Ae. albopictus but rarely detected in Ae. aegypti. In this study, we used a two-step PCR assay to detect Wolbachia in wild-collected samples of Ae. aegypti. The PCR products were sequenced to validate amplicons and identify Wolbachia strains. A loop-mediated isothermal amplification (LAMP) assay was developed and used for detecting Wolbachia in selected mosquito specimens as well. We found Wolbachia in 85/148 (57.4%) wild Ae. aegypti specimens from various cities in New Mexico and in 2/46 (4.3%) from St. Augustine, Florida. We did not detect Wolbachia in 94 samples of Ae. aegypti from Deer Park, Harris County, Texas. Wolbachia detected in Ae. aegypti from both New Mexico and Florida was the wAlbB strain of Wolbachia pipientis. A Wolbachia positive colony of Ae. aegypti was established from pupae collected in Las Cruces, New Mexico in 2018. The infected females of this strain transmitted Wolbachia to their progeny when crossed with males of Rockefeller strain of Ae. aegypti, which does not carry Wolbachia. In contrast, none of the progeny of progeny of Las Cruces males mated to Rockefeller females were infected with Wolbachia.

scholarly journals Recent outbreaks of chikungunya virus (CHIKV) in Africa and Asia are driven by a variant carrying mutations associated with increased fitness for Aedes aegypti

2018 ◽  
Author(s):  
Irina Maljkovic Berry ◽  
Fredrick Eyase ◽  
Simon Pollett ◽  
Samson Limbaso Konongoi ◽  
Katherine Figueroa ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Chikungunya Virus ◽  
Control Strategies ◽  
Vector Competence ◽  
Virus Transmission ◽  
New Delhi ◽  
African Countries ◽  
Global Spread ◽  
Large Outbreak ◽  
The Impact

AbstractBackgroundIn 2016, a chikungunya virus (CHIKV) outbreak was reported in Mandera, Kenya. This was the first major CHIKV outbreak in the country since the global re-emergence of this virus, which arose as an initial outbreak in Kenya in 2004. Therefore, we collected samples and sequenced viral genomes from the 2016 Mandera outbreak.Methodology/Principal FindingsAll Kenyan genomes contained two mutations, E1:K211E and E2:V264A, recently reported to have an association with increased infectivity, dissemination and transmission in the Aedes aegypti (Ae. aegypti) vector. Phylogeographic inference of temporal and spatial virus relationships using Bayesian approaches showed that this Ae. aegypti adapted strain emerged within the East, Central, and South African (ECSA) lineage of CHIKV between 2005 and 2008, most probably in India. It was also in India where the first large outbreak caused by this strain appeared, in New Delhi, 2010. More importantly, our results also showed that this strain is no longer contained to India, and that it has more recently caused several major outbreaks of CHIKV, including the 2016 outbreaks in India, Pakistan and Kenya, and the 2017 outbreak in Bangladesh. In addition to its capability to cause large outbreaks in different regions of the world, this CHIKV strain has the capacity to replace less adapted wild type strains in Ae. aegypti-rich regions. Indeed, all the latest full CHIKV genomes of the ECSA Indian Ocean Lineage (IOL), from the regions of high Ae. aegypti prevalence, carry these two mutations, including samples collected in Japan, Australia, and China.Conclusions/SignificanceOur results point to the importance of continued genomic-based surveillance of this strain’s global spread, and they prompt urgent vector competence studies in Asian and African countries, in order to assess the level of vector receptiveness, virus transmission, and the impact this might have on this strain’s ability to cause major outbreaks.Author summaryChikungunya virus (CHIKV) causes a debilitating infection with high fever, intense muscle and bone pain, rash, nausea, vomiting and headaches, and persistent and/or recurrent joint pains for months or years after contracting the virus. CHIKV is spread by two mosquito vectors, Aedes albopictus and Aedes aegypti, with increased presence around the globe. In this study, we report global spread of a CHIKV strain that carries two mutations that have been suggested to increase this virus’ ability to infect the Aedes aegypti mosquito, as well as to increase CHIKV’s ability to be transmitted by this vector. We show that this strain appeared sometime between 2005 and 2008, most probably in India, and has now spread to Africa, Asia, and Australia. We show that this strain is capable of driving large outbreaks of CHIKV in the human population, causing recent major outbreaks in Kenya, Pakistan, India and Bangladesh. Thus, our results stress the importance of monitoring this strain’s global spread, as well as the need of improved vector control strategies in the areas of Aedes aegypti prevalence.

scholarly journals Sequential Infection of Aedes aegypti Mosquitoes with Chikungunya Virus and Zika Virus Enhances Early Zika Virus Transmission

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 177 ◽  
Author(s):  
Tereza Magalhaes ◽  
Alexis Robison ◽  
Michael Young ◽  
William Black ◽  
Brian Foy ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Blood Meal ◽  
Zika Virus ◽  
Chikungunya Virus ◽  
Vector Competence ◽  
Virus Transmission ◽  
Mosquito Vector ◽  
Molecular Aspects ◽  
Virus Interactions ◽  
Sequential Infection

In urban settings, chikungunya, Zika, and dengue viruses are transmitted by Aedes aegypti mosquitoes. Since these viruses co-circulate in several regions, coinfection in humans and vectors may occur, and human coinfections have been frequently reported. Yet, little is known about the molecular aspects of virus interactions within hosts and how they contribute to arbovirus transmission dynamics. We have previously shown that Aedes aegypti exposed to chikungunya and Zika viruses in the same blood meal can become coinfected and transmit both viruses simultaneously. However, mosquitoes may also become coinfected by multiple, sequential feeds on single infected hosts. Therefore, we tested whether sequential infection with chikungunya and Zika viruses impacts mosquito vector competence. We exposed Ae. aegypti mosquitoes first to one virus and 7 days later to the other virus and compared infection, dissemination, and transmission rates between sequentially and single infected groups. We found that coinfection rates were high after sequential exposure and that mosquitoes were able to co-transmit both viruses. Surprisingly, chikungunya virus coinfection enhanced Zika virus transmission 7 days after the second blood meal. Our data demonstrate heterologous arbovirus synergism within mosquitoes, by unknown mechanisms, leading to enhancement of transmission under certain conditions.

Selection of Aedes aegypti (Diptera: Culicidae) strains that are susceptible or refractory to Dengue-2 virus

2013 ◽  
Vol 145 (3) ◽  
pp. 273-282 ◽  
Author(s):  
Paola A. Caicedo ◽  
Olga L. Barón ◽  
Mauricio Pérez ◽  
Neal Alexander ◽  
Carl Lowenberger ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Molecular Mechanisms ◽  
Selection Process ◽  
Control Strategies ◽  
Vector Competence ◽  
Survival Rates ◽  
Kaplan Meier ◽  
Genetic And Environmental Factors ◽  
Seven Generations ◽  
Selection Of

AbstractThe vector competence (VC) of Aedes aegypti (Linnaeus) (Diptera: Culicidae) varies geographically and is affected by both genetic and environmental factors. Understanding the molecular mechanisms that influence VC may help develop novel control strategies. The selection of susceptible and refractory strains is the first step in this process. We collected immature A. aegypti in the field and established strains that were susceptible and refractory to Dengue-2 virus by isofamily selection through several generations. Infection was detected by immunofluorescence of head or midgut tissues to determine infection barriers and the % of VC by tissue. We selected three strains: Susceptible (Cali-S) (96.4% susceptible at F19), Refractory with a midgut escape barrier (Cali-MEB) (44.1% refractory at F15), and Refractory with a midgut infection barrier (Cali-MIB) (40% refractory at F16). The effects of the infection were measured using Kaplan–Meier survival rates over the first seven generations. All selected strains showed a similar decrease in survival and in the number of eggs laid/female through the seven generations, suggesting that changes were a result of the selection process rather than the virus infection. The results of this study suggest that VC is associated with multiple genes, which have additive effects on susceptibility.

scholarly journals Wolbachia pipientis occurs in Aedes aegypti populations in New Mexico and Florida, USA

2019 ◽  
Vol 9 (10) ◽  
pp. 6148-6156 ◽  
Author(s):  
Aditi Kulkarni ◽  
Wanqin Yu ◽  
Jinjin Jiang ◽  
Concepcion Sanchez ◽  
Ajit K. Karna ◽  
...  
Keyword(s):  
New Mexico ◽  
Aedes Aegypti ◽  
Wolbachia Pipientis

scholarly journals Vector competence of Aedes aegypti and Culex quinquefasciatus from the metropolitan area of Guadalajara, Jalisco, Mexico for Zika virus

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Darwin Elizondo-Quiroga ◽  
Miriam Ramírez-Medina ◽  
Abel Gutiérrez-Ortega ◽  
Armando Elizondo-Quiroga ◽  
José Esteban Muñoz-Medina ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Zika Virus ◽  
Vector Competence ◽  
Virus Transmission ◽  
Blood Feeding ◽  
Surveillance Program ◽  
Virus Spread ◽  
Zikv Infection ◽  
Almost All

AbstractZika virus (ZIKV) is a mosquito-borne pathogen discovered in the late 40’s in Uganda during a surveillance program for yellow fever. By 2014 the virus reached Eastern Island in the Americas, and two years later, the virus spread to almost all countries and territories of the Americas. The mosquito Aedes aegypti has been identified as the main vector of the disease, and several researchers have also studied the vector competence of Culex quinquefasciatus in virus transmission. The aim of the present study was to evaluate the vector competence of Ae. aegypti and Cx. quinquefasciatus in order to understand their roles in the transmission of ZIKV in Guadalajara, Jalisco, Mexico. In blood feeding laboratry experiments, we found that Ae. aegypti mosquitoes showed to be a competent vector able to transmit ZIKV in this area. On the other hand, we found that F0 Cx. quinquefasciatus mosquitoes are refractory to ZIKV infection, dissemination and transmission.

scholarly journals Aedes aegypti Infection With Trypanosomatid Strigomonas culicis Alters Midgut Redox Metabolism and Reduces Mosquito Reproductive Fitness

2021 ◽  
Vol 11 ◽  
Author(s):  
Ana Cristina S. Bombaça ◽  
Ana Caroline P. Gandara ◽  
Vitor Ennes-Vidal ◽  
Vanessa Bottino-Rojas ◽  
Felipe A. Dias ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Aedes Aegypti ◽  
Antioxidant System ◽  
Control Strategies ◽  
Vector Competence ◽  
Health Impact ◽  
Reproductive Fitness ◽  
Insect Immunity ◽  
Transcriptional Modulation ◽  
Immune Related Genes

Aedes aegypti mosquitoes transmit arboviruses of important global health impact, and their intestinal microbiota can influence vector competence by stimulating the innate immune system. Midgut epithelial cells also produce toxic reactive oxygen species (ROS) by dual oxidases (DUOXs) that are essential players in insect immunity. Strigomonas culicis is a monoxenous trypanosomatid that naturally inhabits mosquitoes; it hosts an endosymbiotic bacterium that completes essential biosynthetic pathways of the parasite and influences its oxidative metabolism. Our group previously showed that S. culicis hydrogen peroxide (H2O2)-resistant (WTR) strain is more infectious to A. aegypti mosquitoes than the wild-type (WT) strain. Here, we investigated the influence of both strains on the midgut oxidative environment and the effect of infection on mosquito fitness and immunity. WT stimulated the production of superoxide by mitochondrial metabolism of midgut epithelial cells after 4 days post-infection, while WTR exacerbated H2O2 production mediated by increased DUOX activity and impairment of antioxidant system. The infection with both strains also disrupted the fecundity and fertility of the females, with a greater impact on reproductive fitness of WTR-infected mosquitoes. The presence of these parasites induced specific transcriptional modulation of immune-related genes, such as attacin and defensin A during WTR infection (11.8- and 6.4-fold, respectively) and defensin C in WT infection (7.1-fold). Thus, we propose that A. aegypti oxidative response starts in early infection time and does not affect the survival of the H2O2-resistant strain, which has a more efficient antioxidant system. Our data provide new biological aspects of A. aegypti–S. culicis relationship that can be used later in alternative vector control strategies.

scholarly journals Engineered resistance to Zika virus in transgenic Aedes aegypti expressing a polycistronic cluster of synthetic small RNAs

2019 ◽  
Vol 116 (9) ◽  
pp. 3656-3661 ◽  
Author(s):  
Anna Buchman ◽  
Stephanie Gamez ◽  
Ming Li ◽  
Igor Antoshechkin ◽  
Hsing-Han Li ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Zika Virus ◽  
Small Rnas ◽  
Sterile Insect Technique ◽  
Control Strategies ◽  
Vector Competence ◽  
Gene Drive ◽  
Artificial Infection ◽  
Transmission Rates ◽  
Arboviral Transmission

Recent Zika virus (ZIKV) outbreaks have highlighted the necessity for development of novel vector control strategies to combat arboviral transmission, including genetic versions of the sterile insect technique, artificial infection with Wolbachia to reduce population size and/or vectoring competency, and gene drive-based methods. Here, we describe the development of mosquitoes synthetically engineered to impede vector competence to ZIKV. We demonstrate that a polycistronic cluster of engineered synthetic small RNAs targeting ZIKV is expressed and fully processed in Aedes aegypti, ensuring the formation of mature synthetic small RNAs in the midgut where ZIKV resides in the early stages of infection. Critically, we demonstrate that engineered Ae. aegypti mosquitoes harboring the anti-ZIKV transgene have significantly reduced viral infection, dissemination, and transmission rates of ZIKV. Taken together, these compelling results provide a promising path forward for development of effective genetic-based ZIKV control strategies, which could potentially be extended to curtail other arboviruses.

scholarly journals Wolbachia strain w AlbB maintains high density and dengue inhibition following introduction into a field population of Aedes aegypti

2020 ◽  
Vol 376 (1818) ◽  
pp. 20190809 ◽  
Author(s):  
Noor Afizah Ahmad ◽  
Maria-Vittoria Mancini ◽  
Thomas H. Ant ◽  
Julien Martinez ◽  
Ghazali M. R. Kamarul ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Control Strategies ◽  
Scale Up ◽  
Virus Transmission ◽  
Kuala Lumpur ◽  
Virus Dissemination ◽  
Laboratory Colony ◽  
Dengue Control ◽  
Additional Support

Aedes aegypti mosquitoes carrying the w AlbB Wolbachia strain show a reduced capacity to transmit dengue virus. w AlbB has been introduced into wild Ae. aegypti populations in several field sites in Kuala Lumpur, Malaysia, where it has persisted at high frequency for more than 2 years and significantly reduced dengue incidence. Although these encouraging results indicate that w AlbB releases can be an effective dengue control strategy, the long-term success depends on w AlbB maintaining high population frequencies and virus transmission inhibition, and both could be compromised by Wolbachia– host coevolution in the field. Here, w AlbB-carrying Ae. aegypti collected from the field 20 months after the cessation of releases showed no reduction in Wolbachia density or tissue distribution changes compared to a w AlbB laboratory colony. The w AlbB strain continued to induce complete unidirectional cytoplasmic incompatibility, showed perfect maternal transmission under laboratory conditions, and retained its capacity to inhibit dengue. Additionally, a field-collected w AlbB line was challenged with Malaysian dengue patient blood, and showed significant blocking of virus dissemination to the salivary glands. These results indicate that w AlbB continues to inhibit currently circulating strains of dengue in field populations of Ae. aegypti , and provides additional support for the continued scale-up of Wolbachia wAlbB releases for dengue control. This article is part of the theme issue ‘Novel control strategies for mosquito-borne diseases’.

scholarly journals Permethrin Resistance in Aedes aegypti Affects Aspects of Vectorial Capacity

Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Tse-Yu Chen ◽  
Chelsea T. Smartt ◽  
Dongyoung Shin
Keyword(s):  
Aedes Aegypti ◽  
Sodium Channel ◽  
Mosquito Control ◽  
Vector Competence ◽  
Vectorial Capacity ◽  
Parental Population ◽  
Control Programs ◽  
Channel Gene ◽  
Sodium Channel Gene ◽  
Specific Pcr

Aedes aegypti, as one of the vectors transmitting several arboviruses, is the main target in mosquito control programs. Permethrin is used to control mosquitoes and Aedes aegypti get exposed due to its overuse and are now resistant. The increasing percentage of permethrin resistant Aedes aegypti has become an important issue around the world and the potential influence on vectorial capacity needs to be studied. Here we selected a permethrin resistant (p-s) Aedes aegypti population from a wild Florida population and confirmed the resistance ratio to its parental population. We used allele-specific PCR genotyping of the V1016I and F1534C sites in the sodium channel gene to map mutations responsible for the resistance. Two important factors, survival rate and vector competence, that impact vectorial capacity were checked. Results indicated the p-s population had 20 times more resistance to permethrin based on LD50 compared to the parental population. In the genotyping study, the p-s population had more homozygous mutations in both mutant sites of the sodium channel gene. The p-s adults survived longer and had a higher dissemination rate for dengue virus than the parental population. These results suggest that highly permethrin resistant Aedes aegypti populations might affect the vectorial capacity, moreover, resistance increased the survival time and vector competence, which should be of concern in areas where permethrin is applied.

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