Intrinsic studies of Euphorbia antiquorum L . latex extracts against human bacterial pathogens and mosquito vector Aedes aegypti , Culex quinquefasciatus (Diptera: Culicidae)

2017 ◽  
Vol 10 ◽  
pp. 75-82 ◽  
Author(s):  
Rajkuberan Chandrasekaran ◽  
Sathishkumar Gnanasekar ◽  
Prabukumar Seetharaman ◽  
Muthukumar Krishnan ◽  
Sivaramakrishnan Sivaperumal
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Bacterial Pathogens ◽  
Mosquito Vector

scholarly journals Molecular analysis of targeted insecticide resistance gene mutations in field Aedes aegypti and Culex quinquefasciatus mosquito vectors of arboviruses from Saudi Arabia

2020 ◽  
Author(s):  
Yuan Fang ◽  
Tambo Ernest ◽  
Jing-Bo Xue ◽  
Yi Zhang ◽  
Xiao-Nong Zhou ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Aedes Aegypti ◽  
Insecticide Resistance ◽  
Resistance Gene ◽  
Culex Quinquefasciatus ◽  
Direct Sequencing ◽  
Mosquito Species ◽  
Gene Mutations ◽  
Mosquito Vector ◽  
The Status

Abstract Background: Gene mutations on target sites can be a valuable reference to the status of insecticide resistance. Jeddah, a global commercial and major port-of-entry city, is bearing the most (>70%) dengue disease burden and the population of the dengue vector Aedes aegypti (Linnaeus, 1762) in Saudi Arabia. Culex quinquefasciatus Say, 1823 is a second example as one of the major arboviral vectors in the region. However, the status of insecticide resistance and targeted site mutations on the responsible genes are not fully characterized.Methods: We randomly sampled both mosquito species, Ae. aegypti (25 individuals) and Cx. quinquefasciatus (24 individuals) across Jeddah by daily mosquito surveillance in 2016 to detect the resistance-associated target site mutations on the voltage gated sodium channel (VGSC) and acetylcholinesterase 1 (ace-1) genes by PCR amplification and direct sequencing. Results: Our findings showed that Ae. aegypti resistance-associated VGSC gene mutations revealed polymorphic mutations on the 989, 1016, and 1534 sites. Additionally, we documented two types of introns between exons 20 and 21, however, the I1011M point mutation was undetected. Linkage disequilibrium associations were shown between V1016G with S989P, V1016G with F1534, and V1016G with type A intron. Furthermore, no mutation on ace-1 was identified in Ae. aegypti. In Cx. quinquefasciatus, homozygous L1014F/L1014F (95.23%) on the VGSC and heterozygous G119/G119S (100%) on ace-1 were widely distributed in the samples studied. Analysis of intron sequences obtained in our study and homologous sequences retrieved from GenBank showed that the intron type was significantly associated with 1016 (P = 0.000) allele type, and may reflect the history of insecticide treatment in different continents.Conclusions: To the best of our knowledge, this is the first record of the intron types between exons 20 and 21 on VGSC of Ae. aegypti populations. It can serve as a reference marker to evaluate the local insecticide resistance status. In addition, the first report of insecticide resistance gene mutation being present in field caught Cx. quinquefasciatus in Saudi Arabia. High prevalence of insecticide resistance gene mutations in local primary mosquito vector species alert the urgent need to carry out a comprehensive insecticide resistance surveillance.

scholarly journals Molecular analysis of targeted insecticide resistance gene mutations in field Aedes aegypti and Culex quinquefasciatus mosquito vectors of arboviruses from Saudi Arabia

2020 ◽  
Author(s):  
Yuan Fang ◽  
Tambo Ernest ◽  
Jing-Bo Xue ◽  
Yi Zhang ◽  
Hany A. Kamal ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Aedes Aegypti ◽  
Insecticide Resistance ◽  
Resistance Gene ◽  
Gene Mutation ◽  
Culex Quinquefasciatus ◽  
Mosquito Species ◽  
Gene Mutations ◽  
Mosquito Vector ◽  
The Status

Abstract Background: Gene mutations on target sites can be a valuable reference to the status of insecticide resistance. Jeddah, a global commercial and major port-of-entry city, is bearing the most (>70%) dengue disease burden and the population of the dengue vector Aedes aegypti in Saudi Arabia. Culex quinquefasciatus is a second example as one of the major arboviral vectors in the region. However, the status of insecticide resistance and targeted site mutations on the responsible genes are not fully characterized.Methods: We randomly sampled both mosquito species, Ae. aegypti and Cx. quinquefasciatus across Jeddah by daily mosquito surveillance in 2016 to detect the resistance-associated target site mutations on the voltage gated sodium channel (VGSC) and acetylcholinesterase 1 (ace-1) genes. Results: Our findings showed that Ae. aegypti resistance-associated VGSC gene mutations revealed polymorphic mutations on the 989, 1016, and 1534 sites. Additionally, we documented two types of introns between exons 20 and 21, however, the I1011M point mutation was undetected. Linkage disequilibrium associations were shown between V1016G with S989P, V1016G with F1534, and V1016G with type A intron. Furthermore, no mutation on ace-1 was identified in Ae. aegypti. In Cx. quinquefasciatus, homozygous L1014F/L1014F (95.23%) on the VGSC and heterozygous G119/G119S (100%) on ace-1 were widely distributed in the samples studied. Analysis of intron sequences obtained in our study and homologous sequences retrieved from GenBank showed that the intron type was significantly associated with 1016 (P = 0.000) allele type, and may reflect the history of insecticide treatment in different continents.Conclusions: To the best of our knowledge, this is the first record of the intron types between exons 20 and 21 on VGSC of Ae. aegypti populations, and the first report of insecticide resistance gene mutation being present in field caught Cx. quinquefasciatus in Jeddah, Saudi Arabia. High prevalence of insecticide resistance gene mutations in local primary mosquito vector species alert the urgent need to carry out a comprehensive insecticide resistance gene mutation surveillance and monitoring to guide sustained and effective integrated vector management planning and innovative guidelines in local predominate mosquito populations and mosquito-borne disease control and elimination in Saudi Arabia.

scholarly journals La trampa entomológica Gravid-Aedes Trap, como una alternativa para el monitoreo del mosquito Aedes aegypti, vector del dengue, en las islas Galápagos

Esferas ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 20
Author(s):  
Renato Leon ◽  
Andres Ricardo Carrazco Montalvo ◽  
Ivis Alexi Llerena Martillo ◽  
Agustín Hinojosa Gavilanes
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Mosquito Vector ◽  
Santa Cruz ◽  
Aedes Taeniorhynchus

El mosquito Aedes aegypti es un insecto díptero de importancia médica y es vector de varios arbovirus, entre ellos el dengue, el chikungunya y el Zika. Esta especie es diurna y está adaptada a vivir cerca del ser humano en ambientes urbanos. En 1988 ocurrió el primer brote epidémico de dengue en Ecuador. Desde entonces, es endémico y ocasiona picos de transmisión cada cuatro o cinco años. En las islas Galápagos, el dengue fue introducido en 2002, cuando se reportaron los primeros casos en la isla Santa Cruz. Luego, un brote epidémico de magnitud ocurrió en 2010 en la isla San Cristóbal y, desde entonces, se reportan casos esporádicos cada año. Pocos casos de chikungunya y de Zika también han sido reportados. En el archipiélago, las medidas para controlar a la población de mosquitos se restringen al control vectorial mediante abatización que elimina las larvas, y fumigación con el insecticida Deltametrina para matar a los adultos. Actualmente, no hay un sistema de monitoreo rutinario de las poblaciones de mosquitos, que se considera crucial para evaluar los métodos de control más adecuados y adoptar las medidas más convenientes para combatir al mosquito vector y disminuir la transmisión de enfermedades. Se presenta la trampa Gravid-Aedes Trap (GAT) como una herramienta de monitoreo pasivo y fácil de usar. Su precio es asequible y no requiere de una fuente de electricidad para funcionar. Estudios de evaluación en Brasil muestran la utilidad de esta trampa para el monitoreo y también para el control vectorial. Se reporta un estudio piloto con 10 trampas GAT que se colocaron en Puerto Baquerizo Moreno, en la isla San Cristóbal, y en Puerto Ayora, en Santa Cruz, para monitorear mosquitos. Los resultados preliminares sugieren que esta metodología puede ser efectiva para colectar Aedes aegypti y, por tanto, de potencial utilidad para complementar las estrategias de control vectorial que se llevan a cabo rutinariamente en las islas Galápagos. Otras especies de mosquitos colectadas fueron Culex quinquefasciatus y Aedes taeniorhynchus. Son necesarios estudios a mayor escala para seguir evaluando la utilidad de esta nueva trampa.

A Simple PCR Assay for Discrimination of Dengue Vectors from Nsukka LGA, Nigeria

2020 ◽  
Vol 10 (1) ◽  
pp. 67-77
Author(s):  
Amos Watentena ◽  
Ikem Chris Okoye ◽  
Ikechukwu Eugene Onah ◽  
Onwude Cosmas Ogbonnaya ◽  
Emmanuel Ogudu
Keyword(s):  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Mosquito Species ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Mosquito Vector ◽  
Aedes Mosquitoes ◽  
Allele Specific ◽  
Arboviral Diseases ◽  
Dengue Vectors

Mosquitoes of Aedes species are vectors of several arboviral diseases which continue to be a major public health problem in Nigeria. This study among other things, morphologically identified Aedes mosquitoes collected from Nsukka LGA and used an allele specific PCR amplification for discrimination of dengue vectors. Larval sampling, BG-sentinel traps and modified human landing catches were used for mosquito sampling in two selected autonomous communities of Nsukka LGA (Nsukka and Obimo). A total of 124 Aedes mosquitoes consisting of five (5) different species were collected from April to June, 2019 in a cross-sectional study that covered 126 households, under 76 distinct geographical coordinates. Larvae was mainly collected from plastic containers 73% (n=224), metallic containers 14% (n=43), earthen pots 9% (n=29) and used car tyres 3% (n=9), reared to adult stage 69.35% (n=86), and all mosquitoes were identified using standard morphological keys. Five (5) Aedes mosquito species were captured; Aedes aegypti 83(66.94%), Aedes albopictus 33(26.61%), Aedes simpsoni (4.48%), Aedes luteocephalus (≤1%) and Aedes vittatus (≤1%). Nsukka autonomous community had higher species diversity than Obimo. Allele specific amplification confirmed dengue vectors, Aedes aegypti and Aedes albopictus species on a 2% agarose gel. Since the most recent re-emergence of arboviral diseases is closely associated with Aedes species, findings of this study, therefore, give further evidence about the presence of potential arboviral vectors in Nigeria and describe the role of a simple PCR in discriminating some. Further entomological studies should integrate PCR assays in mosquito vector surveillance.

scholarly journals Temporal and Spatial Blood Feeding Patterns of Urban Mosquitoes in the San Juan Metropolitan Area, Puerto Rico

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 129
Author(s):  
Matthew W. Hopken ◽  
Limarie J. Reyes-Torres ◽  
Nicole Scavo ◽  
Antoinette J. Piaggio ◽  
Zaid Abdo ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Aedes Aegypti ◽  
Metropolitan Area ◽  
Culex Quinquefasciatus ◽  
Urban Ecosystems ◽  
Life Cycles ◽  
Pathogen Transmission ◽  
San Juan ◽  
Vertebrate Species ◽  
Blood Meals

Urban ecosystems are a patchwork of habitats that host a broad diversity of animal species. Insects comprise a large portion of urban biodiversity which includes many pest species, including those that transmit pathogens. Mosquitoes (Diptera: Culicidae) inhabit urban environments and rely on sympatric vertebrate species to complete their life cycles, and in this process transmit pathogens to animals and humans. Given that mosquitoes feed upon vertebrates, they can also act as efficient samplers that facilitate detection of vertebrate species that utilize urban ecosystems. In this study, we analyzed DNA extracted from mosquito blood meals collected temporally in multiple neighborhoods of the San Juan Metropolitan Area, Puerto Rico to evaluate the presence of vertebrate fauna. DNA was collected from 604 individual mosquitoes that represented two common urban species, Culex quinquefasciatus (n = 586) and Aedes aegypti (n = 18). Culex quinquefasciatus fed on 17 avian taxa (81.2% of blood meals), seven mammalian taxa (17.9%), and one reptilian taxon (0.85%). Domestic chickens dominated these blood meals both temporally and spatially, and no statistically significant shift from birds to mammals was detected. Aedes aegypti blood meals were from a less diverse group, with two avian taxa (11.1%) and three mammalian taxa (88.9%) identified. The blood meals we identified provided a snapshot of the vertebrate community in the San Juan Metropolitan Area and have potential implications for vector-borne pathogen transmission.

scholarly journals Ligusticum sinense Nanoemulsion Gel as Potential Repellent against Aedes aegypti, Anopheles minimus, and Culex quinquefasciatus (Diptera: Culicidae)

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 596
Author(s):  
Anuluck Junkum ◽  
Wanchai Maleewong ◽  
Atiporn Saeung ◽  
Danita Champakaew ◽  
Arpaporn Chansang ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Disease Transmission ◽  
Skin Irritation ◽  
Mosquito Vectors ◽  
Plant Family ◽  
Anopheles Minimus ◽  
Human Volunteers ◽  
Nanoemulsion Gel ◽  
Fresh Preparation

Ligusticum sinense Oliv. cv. is a species of Umbelliferae (Apiaceae), a large plant family in the order Apiales. In this study, L. sinense hexane extract nanoemulsion gel (LHE-NEG) was investigated for mosquito repellency and compared to the standard chemical, N,N-diethyl-3-methylbenzamide (DEET), with the goal of developing a natural alternative to synthetic repellents in protecting against mosquito vectors. The results demonstrated that LHE-NEG afforded remarkable repellency against Aedes aegypti, Anopheles minimus, and Culex quinquefasciatus, with median protection times (MPTs) of 5.5 (4.5–6.0), 11.5 (8.5–12.5), and 11.25 (8.5–12.5) h, respectively, which was comparable to those of DEET-nanoemulsion gel (DEET-NEG: 8.5 (7.0–9.0), 12.0 (10.0–12.5), and 12.5 (10.0–13.5) h, respectively). Evaluation of skin irritation in 30 human volunteers revealed no potential irritant from LHE-NEG. The physical and biological stability of LHE-NEG were determined after being kept under heating/cooling cycle conditions. The stored samples of LHE-NEG exhibited some changes in appearance and differing degrees of repellency between those kept for 3 and 6 heating/cooling cycles, thus providing slightly shorter MPTs of 4.25 (4.0–4.5) and 3.25 (2.5–3.5) h, respectively, when compared to those of 5.0 (4.5–6.0) h in fresh preparation. These findings encourage commercially developed LHE-based products as an alternative to conventional synthetic repellents in preventing mosquito bites and helping to interrupt mosquito-borne disease transmission.

scholarly journals Behavioural response of mosquito vectors Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus to synthetic pyrethroid and organophosphorus-based slow-release insecticidal paint

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Sunil Dhiman ◽  
Kavita Yadav ◽  
B. N. Acharya ◽  
Raj Kumar Ahirwar ◽  
D. Sukumaran
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Anopheles Stephensi ◽  
Slow Release ◽  
Disease Risk ◽  
Mosquito Species ◽  
Escape Time ◽  
Behavioural Avoidance ◽  
Vector Mosquito ◽  
Contact Exposure

Abstract Background The direct toxicological impact of insecticides on vector mosquitoes has been well emphasized; however, behavioural responses such as excito-repellency and physical avoidance as a result of insecticide exposure have not been much studied. We have demonstrated the excito-repellency and behavioural avoidance in certain vector mosquito species on exposure to a slow-release insecticidal paint (SRIP) formulation in addition to direct toxicity. Methods A SRIP formulation developed by the Defence Research and Development Establishment, Gwalior, contains chlorpyriphos, deltamethrin and pyriproxyfen as active insecticides. Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti mosquitoes were used to study the excito-repellency response of the formulation. The experiments were performed in a specially designed dual-choice exposure and escape chamber made of transparent polymethyl methacrylate. For the experiments, the SRIP formulation was applied undiluted at a rate of 8 m2 per kg on 15 cm2 metallic surfaces. Mosquitoes were introduced into the exposure chamber, and observations of the movement of mosquitoes into the escape chamber through the exit portal were taken at 1-min intervals for up to 30 min. Results The evaluated formulation displayed strong excito-repellency against all three tested vector mosquito species. Results showed that the ET50 (escape time 50%) for Ae. aegypti, An. stephensi and Cx. quinquefasciatus was 20.9 min, 14.5 min and 17.9 min for contact exposure (CE) respectively. Altogether in CE, the escape rates were stronger in An. stephensi mosquitoes at different time intervals compared to Ae. aegypti and Cx. quinquefasciatus mosquitoes. The probit analysis revealed that the determined ET did not deviate from linearity for both non-contact exposure (NCE) and placebo exposure (PE) (χ2 ≤ 7.9; p = 1.0) for Ae. aegypti mosquitoes and for NCE (χ2 = 8.3; p = 1.0) and PE (χ2 = 1.7; p = 1.0) treatments in Cx. quinquefasciatus. Mortality (24 h) was found to be statistically higher (F = 6.4; p = 0.02) in An. stephensi for CE but did not vary for NCE (p ≥ 0.3) and PE (p = 0.6) treatments among the tested mosquito species. Survival probability response suggested that all the three tested species displayed similar survival responses for similar exposures (χ2 ≤ 2.3; p ≥ 0.1). Conclusion The study demonstrates the toxicity and strong behavioural avoidance in known vector mosquito species on exposure to an insecticide-based paint formulation. The combination of insecticides in the present formulation will broaden the overall impact spectrum for protecting users from mosquito bites. The efficacy data generated in the study provide crucial information on the effectiveness of the tested formulation and could be useful in reducing the transmission intensity and disease risk in endemic countries.

Sign in / Sign up

Export Citation Format

Share Document