scholarly journals The genome trilogy of Anopheles stephensi, an urban malaria vector, reveals structure of a locus associated with adaptation to environmental heterogeneity

2021 ◽  
Author(s):  
Aditi Thakare ◽  
Chaitali Ghosh ◽  
Tejashwini Alalamath ◽  
Naveen Kumar ◽  
Himani Narang ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Environmental Heterogeneity ◽  
Developmental Stages ◽  
Direct Consequence ◽  
Malaria Vectors ◽  
Laboratory Populations ◽  
Exonic Snps ◽  
Water Tanks ◽  
Survival Of The Fittest

Background: Anopheles stephensi is the most menacing malaria vector to watch for in newly urbanizing parts of the world. The fitness is reported to be a direct consequence of the vector adapting to laying eggs in over-head water tanks with street-side water puddles polluted by oil and sewage. Large frequent inversions of malaria vectors are implicated in adaptation. Results: We report the assembly of a strain of An. stephensi of the type-form, collected from a construction site from Chennai (IndCh) in 2016. The genome completes the trilogy with respect to a 16 Mbp inversion (2Rb) in An. stephensi associated with adaptation to environmental heterogeneity. Comparative genome analysis revealed breakpoint structure and allowed extraction of 22,650 segregating SNPs for typing this inversion. Using whole genome sequencing of 82 individual mosquitoes, we conclude that one third of both wild and laboratory populations maintain heterozygous genotype of 2Rb. The large number of SNPs are tailored to assign inversion genotype directly from 1740 exonic SNPs 80% of which are expressed in various developmental stages. Conclusions: The genome trilogy approach accelerates study of fine structure and typing of important inversions in malaria vectors putting the genome resources for the much understudied An. stephensi, on par with the extensively studied malaria vector, Anopheles gambiae. We argue that the IndCh genome is relevant for field translation work compared to those reported earlier by showing that individuals from diverse populations cluster with IndCh pointing to significant commerce between cities, perhaps, allowing for survival of the fittest strain.

scholarly journals Molecular Characterization of the Carboxypeptidase B1 of Anopheles stephensi and Its Evaluation as a Target for Transmission-Blocking Vaccines

2013 ◽  
Vol 81 (6) ◽  
pp. 2206-2216 ◽  
Author(s):  
Abbasali Raz ◽  
Navid Dinparast Djadid ◽  
Sedigheh Zakeri
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Polyclonal Antibodies ◽  
Test Group ◽  
Malaria Vectors ◽  
Parasite Development ◽  
Control Group ◽  
Transmission Blocking ◽  
Content Type ◽  
Transmission Blocking Vaccines

ABSTRACTMalaria is one of the most important infectious diseases in the world, and it has many economic and social impacts on populations, especially in poor countries. Transmission-blocking vaccines (TBVs) are valuable tools for malaria eradication. A study onAnopheles gambiaerevealed that polyclonal antibodies to carboxypeptidase B1 ofA. gambiaecan block sexual parasite development in the mosquito midgut. Hence, it was introduced as a TBV target in regions whereA. gambiaeis the main malaria vector. However, in Iran and neighboring countries as far as China, the main malaria vector isAnopheles stephensi. Also, the genome of this organism has not been sequenced yet. Therefore, in this study, carboxypeptidase B1 ofA. stephensiwas characterized by genomic and proteomic approaches. Furthermore, its expression pattern after ingestion ofPlasmodium falciparumgametocytes and the effect of anti-CPBAs1 antibodies on sexual parasite development were evaluated. Our results revealed that thecpbAs1expression level was increased after ingestion of the mature gametocytes ofP. falciparumand that anti-CPBAs1 directed antibodies could significantly reduce the mosquito infection rate in the test group compared with the control group. Therefore, according to our findings and with respect to the high similarity of carboxypeptidase enzymes between the two main malaria vectors in Africa (A. gambiae) and Asia (A. stephensi) and the presence of other sympatric vectors, CPBAs1 could be introduced as a TBV candidate in regions whereA. stephensiis the main malaria vector, and this will broaden the scope for the potential wider application of CPBAs1 antigen homologs/orthologs.

scholarly journals Anopheles stephensi as an emerging malaria vector in the Horn of Africa with high susceptibility to Ethiopian Plasmodium vivax and Plasmodium falciparum isolates

2020 ◽  
Author(s):  
Temesgen Ashine ◽  
Hiwot Teka ◽  
Endashaw Esayas ◽  
Louisa A. Messenger ◽  
Wakweya Chali ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Urban Areas ◽  
Anopheles Stephensi ◽  
Developmental Stages ◽  
Infection Status ◽  
Horn Of Africa ◽  
High Susceptibility ◽  
Blood Meal Source ◽  
Membrane Feeding ◽  
Genetic Complexity

AbstractAnopheles stephensi, an efficient Asian malaria vector, recently spread into the Horn of Africa and may increase malaria receptivity in African urban areas. We assessed occurrence, genetic complexity, blood meal source and infection status of An. stephensi in Awash Sebat Kilo town, Ethiopia. We used membrane feeding assays to assess competence of local An. stephensi to P. vivax and P. falciparum isolates from clinical patients. 75.3% of the examined waterbodies were infested with An. stephensi developmental stages that were genetically closely related to isolates from Djibouti and Pakistan. Both P. vivax and P. falciparum were detected in wild-caught adult An. stephensi. Local An. stephensi was more receptive to P. vivax compared to a colony of An. arabiensis. We conclude that An. stephensi is an established vector in this part of Ethiopia, highly permissive for local P. vivax and P. falciparum isolates and presents an important new challenge for malaria control.Summary of the articleAn. stephensi, a metropolitan malaria vector that recently expanded to the Horn of African, was highly susceptible to local P. falciparum and P. vivax isolates from Ethiopia and may increase malariogenic potential of rapidly expanding urban settings in Africa.

scholarly journals Efficacy of Extractions of Iranian Native Plants against Main Malaria Vector, Anopheles stephensi in Iran for Making Appropriate Formulation for Disease ControlBackground: Malaria is the main vector–borne disease worldwide. There are several reports of in

2020 ◽  
Author(s):  
Hassan Vatandoost ◽  
Fatemeh Nikpour ◽  
Ahmad Ali Hanafi-Bojd ◽  
Mohammadd Reza Abai ◽  
Mahnaz Khanavi ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Eucalyptus Camaldulensis ◽  
Malaria Vectors ◽  
Thymus Vulgaris ◽  
Native Plant ◽  
Mentha Spicata ◽  
Vector Borne Disease ◽  
Vector Borne ◽  
Lc50 And Lc90

Background: Malaria is the main vector–borne disease worldwide. There are several reports of insecticide resistant in malaria vectors worldwide due to using different insecticides. The aim of this study was to evaluate different native plant extortions against main malaria vector, Anopheles stephensi in Iran for choosing the appropriate plant for formula­tion and use for vector control. Methods: The larvae of An. stephensi were reared in insectary, extraction of plants were carried out at department of Pharmacology. The standard WHO method for biological tests was used for calculation of LC50 and LC90. Probit regra­tion lines were plotted for calculation of LC50 and LC90. Results: In this study several plants including: Mentha spicata, Cymbopogon olivieri, Azadirachta indica, Melia azeda­rach, Lagetes minuta, Calotropis procera, Eucalyptus camaldulensis, Cupressus arizonica, Thymus vulgaris, Lawsonia inermis, Cedrus deodara, Cionura erecta, Bunium persicum, Carum carvi, Artemisia dracunculus, Rosmarinus offici­nalis were used. Results showed that Mentha spicata and Eucalyptus camaldulensis, had the lowest and highest LC50 respectively. Conclusion: Results indicated that Mentha spicata and Eucalyptus camaldulensis, had the lowest and highest LC50 re­spectively. Several other plant extract also showed significant mortality. The formulation of these plants should be pre­pared and evaluate at the field condition against malaria vectors.  

scholarly journals Malaria vector species composition and entomological indices following indoor residual spraying in regions bordering Lake Victoria, Tanzania

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Charles Kakilla ◽  
Alphaxard Manjurano ◽  
Karen Nelwin ◽  
Jackline Martin ◽  
Fabian Mashauri ◽  
...  
Keyword(s):  
Species Composition ◽  
Vector Control ◽  
Malaria Vector ◽  
Lake Victoria ◽  
Indoor Residual Spraying ◽  
Transmission Risk ◽  
Malaria Vectors ◽  
Vector Species ◽  
Sporozoite Rate ◽  
Pirimiphos Methyl

Abstract Background Vector control through long-lasting insecticidal nets (LLINs) and focal indoor residual spraying (IRS) is a major component of the Tanzania national malaria control strategy. In mainland Tanzania, IRS has been conducted annually around Lake Victoria basin since 2007. Due to pyrethroid resistance in malaria vectors, use of pyrethroids for IRS was phased out and from 2014 to 2017 pirimiphos-methyl (Actellic® 300CS) was sprayed in regions of Kagera, Geita, Mwanza, and Mara. Entomological surveillance was conducted in 10 sprayed and 4 unsprayed sites to determine the impact of IRS on entomological indices related to malaria transmission risk. Methods WHO cone bioassays were conducted monthly on interior house walls to determine residual efficacy of pirimiphos-methyl CS. Indoor CDC light traps with or without bottle rotator were hung next to protected sleepers indoors and also set outdoors (unbaited) as a proxy measure for indoor and outdoor biting rate and time of biting. Prokopack aspirators were used indoors to capture resting malaria vectors. A sub-sample of Anopheles was tested by PCR to determine species identity and ELISA for sporozoite rate. Results Annual IRS with Actellic® 300CS from 2015 to 2017 was effective on sprayed walls for a mean of 7 months in cone bioassay. PCR of 2016 and 2017 samples showed vector populations were predominantly Anopheles arabiensis (58.1%, n = 4,403 IRS sites, 58%, n = 2,441 unsprayed sites). There was a greater proportion of Anopheles funestus sensu stricto in unsprayed sites (20.4%, n = 858) than in sprayed sites (7.9%, n = 595) and fewer Anopheles parensis (2%, n = 85 unsprayed, 7.8%, n = 591 sprayed). Biting peaks of Anopheles gambiae sensu lato (s.l.) followed periods of rainfall occurring between October and April, but were generally lower in sprayed sites than unsprayed. In most sprayed sites, An. gambiae s.l. indoor densities increased between January and February, i.e., 10–12 months after IRS. The predominant species An. arabiensis had a sporozoite rate in 2017 of 2.0% (95% CI 1.4–2.9) in unsprayed sites compared to 0.8% (95% CI 0.5–1.3) in sprayed sites (p = 0.003). Sporozoite rates were also lower for An. funestus collected in sprayed sites. Conclusion This study contributes to the understanding of malaria vector species composition, behaviour and transmission risk following IRS around Lake Victoria and can be used to guide malaria vector control strategies in Tanzania.

scholarly journals Reduced susceptibility to selected synthetic pyrethroids in urban malaria vector Anopheles stephensi: a case study in Mangalore city, South India

2010 ◽  
Vol 9 (1) ◽  
pp. 179 ◽  
Author(s):  
Satyanarayan Tiwari ◽  
Susanta K Ghosh ◽  
Vijay P Ojha ◽  
Aditya P Dash ◽  
Kamaraju Raghavendra
Keyword(s):  
Malaria Vector ◽  
South India ◽  
Anopheles Stephensi ◽  
Synthetic Pyrethroids ◽  
Urban Malaria

scholarly journals Astrodaucus persicus as a new source of bioinsectisides against malaria vector, Anopheles stephensi

2017 ◽  
Vol 10 (9) ◽  
pp. 896-899 ◽  
Author(s):  
Saied Goodarzi ◽  
Hassan Vatandoost ◽  
Mohammad Reza Abai ◽  
Saeed Tavakoli ◽  
Amir Hatamian ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi

Does the roof type of a house influence the presence of adult Anopheles stephensi, urban malaria vector? – evidence from a few slum settings in Chennai, India

2021 ◽  
Author(s):  
Sangamithra Ravishankaran ◽  
Aswin Asokan ◽  
N. A. Johnson Amala Justin ◽  
Shalu Thomas ◽  
Vasna Joshua ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Anopheles Stephensi ◽  
Urban Malaria

scholarly journals Insecticide resistance in Anopheles stephensi in Somali Region, eastern Ethiopia

2020 ◽  
Author(s):  
Solomon Yared ◽  
Araya Gebressielasie ◽  
Lambodhar Damodaran ◽  
Victoria Bonnell ◽  
Karen Lopez ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Anopheles Stephensi ◽  
Mortality Rates ◽  
Resistance Mechanisms ◽  
World Health ◽  
Malaria Vectors ◽  
Resistance Locus ◽  
Eastern Ethiopia ◽  
Pyrethroid Insecticides ◽  
Pirimiphos Methyl

Abstract Background The movement of malaria vectors into new areas is a growing concern in the efforts to control malaria. The recent report of Anopheles stephensi in eastern Ethiopia has raised the necessity to understand the insecticide resistance status of the vector in the region to better inform vector-based interventions. The aim of this study was to evaluate insecticide resistance in An. stephensi in eastern Ethiopia using two approaches: 1) World Health Organization (WHO) bioassay tests in An. stephensi; and 2) genetic analysis of insecticide resistance genes in An. stephensi in eastern Ethiopia. Methods Mosquito larvae and pupae were collected from Kebri Dehar. Insecticide susceptibility of An. stephensi was tested withmalathion 5%, bendiocarb 0.1%, propoxur 0.1%, deltamethrin 0.05%, permethrin 0.75%, Pirimiphos-methyl 0.25% and DDT 4%, according to WHO standard protocols. In this study, the knockdown resistance locus (kdr) in the voltage gated sodium channel (vgsc) and ace1R locus in the acetylcholinesterase gene (ace-1) were analysed in An. stephensi. Results All An. stephensi samples were resistant to carbamates, with mortality rates of 23% and 21% for bendiocarb and propoxur, respectively. Adult An. stephensi was also resistant to pyrethroid insecticides with mortality rates 67% for deltamethrin and 53% for permethrin. Resistance to DDT and malathion was detected in An. stephensi with mortality rates of 32% as well as An. stephensi was resistance to pirimiphos-methyl with mortality rates 14%. Analysis of the insecticide resistance loci revealed the absence of kdr L1014F and L1014S mutations and the ace1R G119S mutation. Conclusion Overall, these findings support that An. stephensi is resistant to several classes of insecticides, most notably pyrethroids. However, the absence of the kdr L1014 gene may suggest non-target site resistance mechanisms. Continuous insecticide resistance monitoring should be carried out in the region to confirm the documented resistance and exploring mechanisms conferring resistance in An. stephensi in Ethiopia.

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