Assessment of insecticide resistance in Culex quinquefasciatus Say with first report on the presence of L1014F mutation from northern districts of West Bengal, India

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.

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Studies on seasonal fluctuation of different indices related to filarial vector, Culex quinquefasciatus around foothills of Susunia of West Bengal, India

Asian Pacific Journal of Tropical Medicine ◽

10.1016/s1995-7645(10)60174-5 ◽

2010 ◽

Vol 3 (9) ◽

pp. 727-730 ◽

Cited By ~ 5

Author(s):

Manas Paramanik ◽

Goutam Chandra

Keyword(s):

Culex Quinquefasciatus ◽

West Bengal ◽

Seasonal Fluctuation ◽

Filarial Vector

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Organophosphorus insecticide resistance in a new strain of Culex quinquefasciatus (Diptera: Culicidae) from Tanga, Tanzania

Bulletin of Entomological Research ◽

10.1017/s0007485300041791 ◽

1993 ◽

Vol 83 (1) ◽

pp. 67-74 ◽

Cited By ~ 3

Author(s):

A. Khayrandish ◽

R.J. Wood

Keyword(s):

Insecticide Resistance ◽

Culex Quinquefasciatus ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Laboratory Culture ◽

Fourth Instar ◽

Resistance Allele ◽

Susceptible Control ◽

The Mean

AbstractFourth instar larvae of a new strain of Culex quinquefasciatus Say from Tanzania (TANGA) were tested for insecticide resistance. Initially, the resistance ratio (RR) to chlorpyrifos was 41.8, to temephos 30.8, to propoxur 3.7. After 2–3 years of laboratory culture, resistance to chlorpyrifos and propoxur had declined (chlorpyrifos 5.7, 3.8; propoxur 1.9, permethrin 1.9). Significant synergism was found between s, s, s-tributyl trithiophosphate (DEF) and chlorphyrifos, reducing the RR from 8.0 to 2.5. Synergism between piperonyl butoxide and permethrin was less than in a susceptible control strain. Twelve esterase isozymes of different relative mobilities (Rm) on polyacrylamide gel electrophoresis were identified, ten of which remained when the strain was reinvestigated two years (approximately 32 generations) later. Null activity for all but one of these bands was observed in some larvae. Four esterase bands (Rm 0.25, 0.27, 0.31, 0.34, designated A2, A3, B2, B3) showed polymorphism in activity, with very intense bands in some larvae. The mean frequency of bands with activity greater than standard, declined as organophosphorus (OP) resistance declined, but resistance was unconnected with the frequency of nulls at these positions. In mass larval assays of in vitro sensitivity of acetylcholinesterase (AChE) to propoxur, the I50 exceeded 10x10−4M, compared with 0.1x10−4M in a reverted resistant strain (RANGOON). Single larvel assays revealed heterogeneity, which was interpreted on the basis of an AChE resistance allele (AceR) with a frequency of 0.23.

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Occurrence of L1014F and L1014S mutations in insecticide resistant Culex quinquefasciatus from filariasis endemic districts of West Bengal, India

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0010000 ◽

2022 ◽

Vol 16 (1) ◽

pp. e0010000

Author(s):

Priyanka Rai ◽

Dhiraj Saha

Keyword(s):

Culex Quinquefasciatus ◽

West Bengal ◽

Economic Status ◽

Minor Role ◽

Resistance Development ◽

Vector Population ◽

A Minor ◽

First Time

Introduction Lymphatic filariasis causes long term morbidity and hampers the socio-economic status. Apart from the available treatments and medication, control of vector population Culex quinquefasciatus Say through the use of chemical insecticides is a widely applied strategy. However, the unrestrained application of these insecticides over many decades has led to resistance development in the vectors. Methods In order to determine the insecticide susceptibility/resistance status of Cx. quinquefasciatus from two filariasis endemic districts of West Bengal, India, wild mosquito populations were collected and assayed against six different insecticides and presence of L1014F; L1014S kdr mutations in the voltage-gated sodium channel gene was also screened along with the use of synergists to evaluate the role of major detoxifying enzymes in resistance development. Results The collected mosquito populations showed severe resistance to insecticides and the two synergists used–PBO (piperonyl butoxide) and TPP (triphenyl phosphate), were unable to restore the susceptibility status of the vector thereupon pointing towards a minor role of metabolic enzymes. kdr mutations were present in the studied populations in varying percent with higher L1014F frequency indicating its association with the observed resistance to pyrethroids and DDT. This study reports L1014S mutation in Cx. quinquefasciatus for the first time.

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Insecticide resistance genes affect Culex quinquefasciatus vector competence for West Nile virus

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2018.2273 ◽

2019 ◽

Vol 286 (1894) ◽

pp. 20182273 ◽

Cited By ~ 3

Author(s):

Célestine M. Atyame ◽

Haoues Alout ◽

Laurence Mousson ◽

Marie Vazeille ◽

Mawlouth Diallo ◽

...

Keyword(s):

West Nile Virus ◽

Insecticide Resistance ◽

Culex Quinquefasciatus ◽

Rift Valley Fever Virus ◽

Vector Competence ◽

Resistance Mechanisms ◽

Transmission Efficiency ◽

West Nile ◽

Valley Fever ◽

Resistant Lines

Insecticide resistance has been reported to impact the interactions between mosquitoes and the pathogens they transmit. However, the effect on vector competence for arboviruses still remained to be investigated. We examined the influence of two insecticide resistance mechanisms on vector competence of the mosquito Culex quinquefasciatus for two arboviruses, Rift Valley Fever virus (RVFV) and West Nile virus (WNV). Three Cx. quinquefasciatus lines sharing a common genetic background were used: two insecticide-resistant lines, one homozygous for amplification of the Ester 2 locus (SA2), the other homozygous for the acetylcholinesterase ace-1 G119S mutation (SR) and the insecticide-susceptible reference line Slab. Statistical analyses revealed no significant effect of insecticide-resistant mechanisms on vector competence for RVFV. However, both insecticide resistance mechanisms significantly influenced the outcome of WNV infections by increasing the dissemination of WNV in the mosquito body, therefore leading to an increase in transmission efficiency by resistant mosquitoes. These results showed that insecticide resistance mechanisms enhanced vector competence for WNV and may have a significant impact on transmission dynamics of arboviruses. Our findings highlight the importance of understanding the impacts of insecticide resistance on the vectorial capacity parameters to assess the overall consequence on transmission.

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