scholarly journals Knockdown Resistance (kdr) Mutations I1532T and F1534S Were Identified in Aedes albopictus Field Populations in Zhejiang Province, Central China

2021 ◽  
Vol 11 ◽  
Author(s):  
Yuyan Wu ◽  
Qinmei Liu ◽  
Yunpeng Qi ◽  
Yinping Wu ◽  
Qinxiang Ni ◽  
...  
Keyword(s):  
Aedes Albopictus ◽  
Mutant Allele ◽  
Pyrethroid Resistance ◽  
Southern China ◽  
Zhejiang Province ◽  
Central China ◽  
Knockdown Resistance ◽  
Resistance Mutations ◽  
Deltamethrin Resistance ◽  
Domain Iii

Aedes albopictus is the only vector that can transmit the dengue virus in Zhejiang Province, central China, and it can develop insecticide resistance due to long-term exposure to pyrethroids. The presence of knockdown resistance (kdr) mutations is one of the mechanisms responsible for pyrethroid resistance, and has been reported in some Ae. albopictus populations in southern China. However, little is known about the DNA diversity of the voltage-gated sodium channel (VGSC) gene in Ae. albopictus populations in central China. Four Ae. albopictus field populations were collected, in Yiwu (YW), Quzhou (QZ), Wenzhou (WZ), and Jiaxing (JX) from Zhejiang Province, central China. The susceptibility of Ae. albopictus adults to three pyrethroids (beta-cypermethrin, deltamethrin, and permethrin) was tested using the WHO tube assay, and Kdr mutations were identified via PCR and sequencing. The relationship between kdr mutations and pyrethroid phenotypes was also analyzed. Of the four populations, none was sensitive to any pyrethroid tested, and the YW population showed the strongest pyrethroid resistance. Non-synonymous kdr mutations were detected in codons 1532 and 1534, domain III. At codon 1534, one mutant allele, TCC(S), was detected in the four populations with a frequency of 42.08%, while at codon 1532, one mutant allele, ACC(T), was detected in the JX and QZ populations, with frequencies of 4.22 and 3.03%, respectively. The F1534S mutant allele was positively correlated with both beta-cypermethrin and deltamethrin resistance phenotypes (OR > 1, P < 0.05), whereas the I1532T mutant allele was possibly negatively correlated with beta-cypermethrin, deltamethrin, and permethrin resistance phenotypes (OR < 1, P > 0.05). In conclusion, resistance and resistance mutations regarding to three pyrethroids are already present in the Ae. Albopictus populations from Zhejiang, central China, which prompts the need to use non-insecticide-based methods of insect control.

scholarly journals The Pattern of Knockdown Resistance Mutations Correlated to the Annual Average Temperature in Field Populations of Aedes Albopictus (Diptera: Culicidae) in China

2021 ◽  
Author(s):  
Hanming Chen ◽  
Qiuming Zhou ◽  
Haowei Dong ◽  
Hao Yuan ◽  
Jie Bai ◽  
...  
Keyword(s):  
Dengue Fever ◽  
Mutation Rate ◽  
Aedes Albopictus ◽  
Mutant Allele ◽  
Pearson Correlation ◽  
Point Mutations ◽  
National Database ◽  
Knockdown Resistance ◽  
Resistance Mutations ◽  
Annual Average

Abstract Background: Aedes albopictus is the main vector of dengue fever in China, distributed from north to south in China. Insecticides are an important method to control the mosquitoes, especially in the outbreak of dengue fever, but insecticide resistance raises the risk of failure to control vector-borne diseases. Knockdown resistance (kdr) caused by point mutations in the VGSC gene is a key mechanism that confers resistance to pyrethroids. To explore the characteristics and possible evolution trend of kdr mutation in Ae. albopictus, we analyzed the kdr mutations of field populations in China in this study.Methods: A total of 1 549 Ae. albopictus were collected from 18 sites in China from 2017 to 2019, as well as 50 individuals from three sites in the 1990s. A fragment of approximately 350 bp from part of S6 segment in the VGSC gene domain III was amplified and sequenced. The haplotypes of VGSC gene were recorded and the parsimony network was constructed using TCS 1.21. The data of annual average temperatures (AAT) of collection sites was acquired from national database. The correlation between AAT of the collection site and the kdr mutation rate was analyzed by Pearson Correlation using SPSS 21.0. Results: The overall frequency of mutant allele F1534 is 45.62%. Nine mutant alleles were detected at codon 1534 in fifteen field populations, namely TCC/TCG (S) (38.86%), TTG/CTG/CTC/TTA (L) (3.71%), TGC (C) (2.68%), CGC (R) (0.27%) and TGG (W) (0.10%). Only one mutant allele ACC (T) was found at codon 1532 with frequency of 6.39% in ten field populations. Moreover, multiple mutations at I1532 and F1534 in a sample appeared in five populations. The 1534 mutation rate was significantly positive related to AAT (Coefficient=0.624, p=0.0056), while the 1532 mutation rate was significantly negative related to AAT (Coefficient=-0.645, p=0.0038). Thirteen haplotypes were inferred, in which six mutant haplotypes were formed by one step, and the other six haplotypes were formed by one more mutations. In the samples from 1990s, no mutant allele was detected at codon 1532 of VGSC gene. However, F1534S/TCC was found in HNHK94 with an unexpected frequency of 100%.ConclusionsKdr mutations are widespread in the field populations of Ae. albopictus in China. Two novel mutant alleles F1534W/TGG and F1534R/CGC were the detected. The 1534 kdr mutation appeared in the population of Ae. albopictus no later than 1990s. F1534 mutation rate is positive correlated to AAT, while I1532 mutation rate is negative correlated to AAT. Insecticide using should be carefully managed to slow down the spread of high-resistance Ae. albopictus populations.

scholarly journals Comparison of the knockdown resistance locus (kdr) in Anopheles stephensi, An. arabiensis, and Culex pipiens s.l. suggests differing mechanisms of pyrethroid resistance in east Ethiopia

2020 ◽  
Author(s):  
Tamar E. Carter ◽  
Araya Gebresilassie ◽  
Shantoy Hansel ◽  
Lambodhar Damodaran ◽  
Callum Montgomery ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Pyrethroid Resistance ◽  
Resistance Mechanism ◽  
Target Site ◽  
Resistance Locus ◽  
Knockdown Resistance ◽  
Resistance Mutations ◽  
Vector Species

AbstractThe malaria vector, Anopheles stephensi, which is typically restricted to South Asia and the Middle East, was recently detected in the Horn of Africa. Controlling the spread of this vector could involve integrated vector control that considers the status of insecticide resistance of multiple vector species in the region. Previous reports indicate that the knockdown resistance mutations (kdr) in the voltage-gated sodium channel (vgsc) are absent in both pyrethroid resistant and sensitive variants of An. stephensi in east Ethiopia but similar information on other vector species in the same areas is limited. In this study, kdr and the neighboring intron was analyzed in An. stephensi, An. arabiensis, and Culex pipiens s. l. collected in east Ethiopia between 2016 and 2017. Sequence analysis revealed that all of Cx. pipiens s.l. (n = 42) and 71.6% of the An. arabiensis (n=67) carried kdr L1014F known to confer target-site pyrethroid resistance. Intronic variation was only observed in An. stephensi (segregating sites = 6, haplotypes = 3) previously shown to have no kdr mutations. In addition, no evidence of non-neutral evolutionary processes was detected at the An. stephensi kdr intron which further supports target-site mechanism not being a major resistance mechanism in this An. stephensi population. Overall, these results suggest differences in evolved mechanisms of pyrethroid/DDT resistance in populations of vector species from the same region. Variation in insecticide resistance mechanisms in East Ethiopian mosquito vectors highlight possible species or population specific biological factors and distinct environmental exposures that shape their evolution.

scholarly journals Analysis of the Knockdown Resistance Locus (kdr) in Anopheles stephensi, An. arabiensis, and Culex pipiens s.l. for Insight Into the Evolution of Target-site Pyrethroid Resistance in Eastern Ethiopia

2022 ◽  
Author(s):  
Tamar E. Carter ◽  
Araya Gebresilassie ◽  
Shantoy Hansel ◽  
Lambodhar Damodaran ◽  
Callum Montgomery ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Anopheles Stephensi ◽  
Pyrethroid Resistance ◽  
Resistance Mechanism ◽  
Target Site ◽  
Knockdown Resistance ◽  
Resistance Mutations ◽  
Vector Species ◽  
Eastern Ethiopia ◽  
Integrated Vector Control

The malaria vector, Anopheles stephensi, which is typically restricted to South Asia and the Middle East, was recently detected in the Horn of Africa. Addressing the spread of this vector could involve integrated vector control that considers the status of insecticide resistance of multiple vector species in the region. Previous reports indicate that the knockdown resistance mutations (kdr) in the voltage-gated sodium channel (vgsc) are absent in both pyrethroid-resistant and pyrethroid-sensitive An. stephensi in eastern Ethiopia; however, similar information about other vector species in the same areas is limited. In this study, kdr and the neighboring intron were analyzed in An. stephensi, An. arabiensis, and Culex pipiens s.l. collected between 2016 and 2017 to determine the evolutionary history of kdr in eastern Ethiopia. A sequence analysis revealed that all of Cx. pipiens s.l. (N = 42) and 71.6% of the An. arabiensis (N = 67) carried kdr L1014F, which is known to confer target-site pyrethroid resistance. Intronic variation was only observed in An. stephensi (six segregating sites, three haplotypes), which was previously shown to have no kdr mutations. In addition, no evidence of non-neutral evolutionary processes was detected at the An. stephensi kdr intron, thereby further supporting the target-site mechanism not being a major resistance mechanism in this An. stephensi population. Overall, these results show key differences in the evolution of target-site pyrethroid/dichlorodiphenyltrichloroethane resistance mutations in populations of vector species from the same region. Variations in insecticide resistance mechanism profiles between eastern Ethiopian mosquito vectors may lead to different responses to insecticides used in integrated vector control.

scholarly journals Phenotypic and molecular analysis of insecticide resistance in Aedes albopictus populations from Greece

2020 ◽  
Author(s):  
Sofia Balaska ◽  
Emmanouil Alexandros Fotakis ◽  
Ilias Kioulos ◽  
Linda Grigoraki ◽  
Spyridoula Mpellou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Molecular Analysis ◽  
Aedes Albopictus ◽  
Pyrethroid Resistance ◽  
Disease Outbreaks ◽  
Control Methods ◽  
Resistance Mutations ◽  
Control Programs ◽  
Southern European Countries

Abstract Background: Aedes albopictus has a well-established presence in southern European countries, associated with recent disease outbreaks (e.g. Chikungunya). Development of insecticide resistance in the vector is a major concern as it’s control mainly relies on the use of biocides. Data on the specie’s resistance status is essential for efficient and sustainable control. Methods: We investigated the insecticide resistance status of several Ae. albopictus populations from Greece. Bioassays were performed against diflubenzuron (DFB), B. thuringiensis var. israelensis (Bti), deltamethrin and malathion. Molecular analysis of known insecticide resistance loci was performed, i.e. voltage-gated sodium channel (VGSC) mutations associated with pyrethroid resistance; presence and frequency of carboxylesterases 3 (CCEae3a) and 6 (CCEae6a) gene amplification associated with organophosphate (OP) resistance and; chitin synthase-1 (CHS-1) for the possible presence of DFB resistance mutations. Results: Bioassays showed full susceptibility to DFB, Bti and deltamethrin, but resistance against the OP malathion. VGSC analysis revealed a widespread distribution of mutations F1534C (in all populations, with allelic frequencies between 6.6% - 68.3%), and I1532T (in 6 populations), but absence of V1016G. CCE gene amplifications were recorded in 8 out of 11 populations. Co-presence of mutation F1534C and CCEae3a amplification was reported in a subgroup of samples. No mutations at the CHS locus I1043 were detected. Conclusions: The results indicate: (i) the suitability of larvicides DFB and Bti for Ae. albopictus control in Greece, (ii) a possible incipient pyrethroid resistance due to the presence of kdr mutations and (iii) a possible reduced efficacy of OPs, in a scenario of re-introducing them for vector control. The study highlights the need for systematic resistance monitoring for developing and implementing appropriate evidence-based control programs. Key words: diagnostic, arbovirus, mosquito tiger, insecticide resistance, vector control, Europe

scholarly journals Bioassay and molecular monitoring of insecticide resistance status in Aedes albopictus populations from Greece, to support evidence-based vector control

2020 ◽  
Author(s):  
Sofia Balaska ◽  
Emmanouil Alexandros Fotakis ◽  
Ilias Kioulos ◽  
Linda Grigoraki ◽  
Spyridoula Mpellou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Aedes Albopictus ◽  
Pyrethroid Resistance ◽  
Disease Outbreaks ◽  
Evidence Based ◽  
Resistance Mutations ◽  
Molecular Monitoring ◽  
Allelic Frequencies ◽  
Control Programs

Abstract Background: Aedes albopictus has a well-established presence in southern European countries, associated with recent disease outbreaks (e.g. Chikungunya). Development of insecticide resistance in the vector is a major concern as its control mainly relies on the use of biocides. Data on the species’ resistance status is essential for efficient and sustainable control. To date the insecticide resistance status of Ae. albopictus populations from Greece against major insecticides used in vector control remains largely unknown. Methods: We investigated the insecticide resistance status of nineteen Ae. albopictus populations from 11 regions of Greece. Bioassays were performed against diflubenzuron (DFB), B. thuringiensis var. israelensis (Bti), deltamethrin and malathion. Known insecticide resistance loci were molecularly analysed, i.e. voltage-gated sodium channel (VGSC) mutations associated with pyrethroid resistance; presence and frequency of carboxylesterases 3 (CCEae3a) and 6 (CCEae6a) gene amplification associated with organophosphate (OP) resistance and; chitin synthase-1 (CHS-1) for the possible presence of DFB resistance mutations. Results: Bioassays showed full susceptibility to DFB, Bti and deltamethrin, but resistance against the OP malathion (range of mortality: 55.30-91.40%). VGSC analysis revealed a widespread distribution of mutations F1534C (in all populations, with allelic frequencies between 6.6% - 68.3%), and I1532T (in 6 populations; allelic frequencies below 22.70%), but absence of V1016G. CCE gene amplifications were recorded in 8 out of 11 populations (overall frequency: 33%). Co-presence of mutation F1534C and CCEae3a amplification was reported in 39 of the 156 samples commonly analysed. No mutations at the CHS-1 locus I1043 were detected. Conclusions: The results indicate: (i) the suitability of larvicides DFB and Bti for Ae. albopictus control in Greece, (ii) possible incipient pyrethroid resistance due to the presence of kdr mutations and (iii) possible reduced efficacy of OPs, in a scenario of re-introducing them for vector control. The study highlights the need for systematic resistance monitoring for developing and implementing appropriate evidence-based control programs.

scholarly journals Knockdown resistance mutations contributing to pyrethroid resistance in Aedes aegypti population, Saudi Arabia

2019 ◽  
Vol 25 (12) ◽  
pp. 905-913 ◽  
Author(s):  
Ommer Dafalla ◽  
Adel Alsheikh ◽  
Waheed Mohammed ◽  
Khalid Shrwani ◽  
Feras Alsheikh ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Aedes Aegypti ◽  
Pyrethroid Resistance ◽  
Knockdown Resistance ◽  
Resistance Mutations ◽  
Aegypti Population

Comparison of Aedes albopictus Monitoring Methods and Dengue Risk Assessment in Central China

2020 ◽  
Vol 12 (4) ◽  
pp. 446-454
Author(s):  
Chuanwei Chen ◽  
Huaiqing Zhang ◽  
Qiyong Liu ◽  
Yu Li ◽  
Jiqi Liu ◽  
...  
Keyword(s):  
Dengue Fever ◽  
Aedes Albopictus ◽  
Rural Areas ◽  
Urban Areas ◽  
Southern China ◽  
Control Strategies ◽  
Distribution Patterns ◽  
Wide Distribution ◽  
Central China ◽  
Monitoring Methods

Dengue fever has been attracting more attention in recent years. Dengue fever is mainly transmitted to humans by the Aedes albopictus mosquito and disease patterns are influenced by its wide distribution and high density during the summer season in China. Dengue epidemics in central China previously occurred exclusively in rural areas, while these recent outbreaks mostly occurred in urban areas in southern China. Until now, the presence of Aedes Albopictus in central China has been scarcely acknowledged. This study is a survey of Aedes and attempts to clarify this new distribution pattern using the Breteau Index (BI) method and a polylactic-glycolic acid (PLGA) copolymer mosquito trap simultaneously in urban and rural areas. The BI can provide a direct value on Aedes density compared to CI. Rural areas are at a higher risk for dengue compared to urban areas in central China. Our findings provide a basis for the prevention and control of dengue vectors, as well as providing information for control strategies for other infectious diseases transmitted by Aedes mosquitoes. Vector control strategy related to the management of diseases transmitted by Aedes should be based on the distribution patterns of different vector species, particularly in the rural environments in central China.

scholarly journals Bioassay and molecular monitoring of insecticide resistance status in Aedes albopictus populations from Greece, to support evidence-based vector control

2020 ◽  
Author(s):  
Sofia Balaska ◽  
Emmanouil Alexandros Fotakis ◽  
Ilias Kioulos ◽  
Linda Grigoraki ◽  
Spyridoula Mpellou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Vector Control ◽  
Aedes Albopictus ◽  
Pyrethroid Resistance ◽  
Disease Outbreaks ◽  
Evidence Based ◽  
Resistance Mutations ◽  
Molecular Monitoring ◽  
Allelic Frequencies ◽  
Control Programmes

Abstract Background: Aedes albopictus has a well-established presence in southern European countries, associated with recent disease outbreaks (e.g. chikungunya). Development of insecticide resistance in the vector is a major concern as its control mainly relies on the use of biocides. Data on the species’ resistance status are essential for efficient and sustainable control. To date the insecticide resistance status of Ae. albopictus populations from Greece against major insecticides used in vector control remains largely unknown. Methods: We investigated the insecticide resistance status of 19 Ae. albopictus populations from 11 regions of Greece. Bioassays were performed against diflubenzuron (DFB), Bacillus thuringiensis var. israelensis (Bti), deltamethrin and malathion. Known insecticide resistance loci were molecularly analysed, i.e. voltage-gated sodium channel (VGSC) mutations associated with pyrethroid resistance; presence and frequency of carboxylesterases 3 (CCEae3a) and 6 (CCEae6a) gene amplification associated with organophosphate (OP) resistance and; chitin synthase-1 (CHS-1) for the possible presence of DFB resistance mutations. Results: Bioassays showed full susceptibility to DFB, Bti and deltamethrin, but resistance against the OP malathion (range of mortality: 55.30–91.40%). VGSC analysis revealed a widespread distribution of the mutations F1534C (in all populations, with allelic frequencies between 6.6–68.3%), and I1532T (in 6 populations; allelic frequencies below 22.70%), but absence of V1016G. CCE gene amplifications were recorded in 8 out of 11 populations (overall frequency: 33%). Co-presence of the F1534C mutation and CCEae3a amplification was reported in 39 of the 156 samples analysed by both assays. No mutations at the CHS-1 I1043 locus were detected. Conclusions: The results indicate: (i) the suitability of larvicides DFB and Bti for Ae. albopictus control in Greece; (ii) possible incipient pyrethroid resistance due to the presence of kdr mutations; and (iii) possible reduced efficacy of OPs, in a scenario of re-introducing them for vector control. The study highlights the need for systematic resistance monitoring for developing and implementing appropriate evidence-based control programmes.

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