Susceptibility to Pyrethroids and the First Report of L1014F kdr Mutation in Culex quinquefasciatus (Diptera: Culicidae) in Colombia

Abstract The use of insecticides for the control of Aedes aegypti (L.) (Diptera: Culicidae) in Colombia has indirectly influenced the susceptibility status of Culex quinquefasciatus Say populations. We evaluated pyrethroid susceptibility in two populations of Cx. quinquefasciatus in the Atlantico Department of Colombia and its possible resistance mechanism (kdr mutation). Bottle bioassays were performed for permethrin, deltamethrin, and λ-cyhalothrin in female mosquitoes of Cx. quinquefasciatus. The resistance ratios (RRs) for KC50 and LC50 for each insecticide in the field populations examined were determined, using the Cartagena strain as the susceptible control. The L1014F kdr mutation was identified in the para gene of the voltage-gated sodium channel (vgsc), along with its allelic and genotypic frequency. Low knockdown resistance (RRKC50) to deltamethrin was found in Puerto Colombia and Soledad populations as well as low resistance to λ-cyalothrin in this latter population. Moderate knockdown resistance to permethrin was found in both populations. At 24 h post-exposure on the other hand, there was low resistance (RRLC50) to permethrin in Puerto Colombia and moderate resistance in Soledad. Moderate resistance to deltamethrin was found in Puerto Colombia and low resistance in Soledad. Low resistance to λ-cyhalothrin was seen in Puerto Colombia and moderate resistance in Soledad. Variability was found in the susceptibility to the pyrethroids in the populations of Cx. quinquefasciatus evaluated, and the L1014F kdr mutation is reported for the first time as a possible pyrethroid resistance mechanism in this species in Colombia.

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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

10.1101/2020.05.13.093898 ◽

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.

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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

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.20-1357 ◽

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.

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Surveillance of a kdr Resistance Mutation in Culex pipiens (Diptera: Culicidae) and Culex quinquefasciatus in California

Journal of Medical Entomology ◽

10.1093/jme/tjz208 ◽

2019 ◽

Vol 57 (2) ◽

pp. 645-648 ◽

Cited By ~ 2

Author(s):

Melissa Hardstone Yoshimizu ◽

Kerry Padgett ◽

Vicki Kramer

Keyword(s):

Allele Frequency ◽

Culex Quinquefasciatus ◽

Disease Transmission ◽

Culex Pipiens ◽

Pyrethroid Resistance ◽

Resistance Mutation ◽

Resistance Allele ◽

Resistant Allele ◽

L1014f Kdr ◽

Control Adult

Abstract Culex pipiens Linnaeus and Culex quinquefasciatus Say are the primary vectors of West Nile and St. Louis encephalitis viruses in California. Pyrethrins and pyrethroids (synthetic pyrethrins) are the most widely used insecticides to control adult stage mosquitoes to prevent disease transmission. The most abundant and widespread mutation associated with pyrethroid resistance is the L1014F mutation of the voltage-sensitive sodium channel gene. Statewide, based on the testing of almost 2,000 mosquitoes from 14 counties, the resistant allele frequency was 71%. Although the L1014F mutation was found in all counties assessed, the resistance allele profiles differed between regions of California. The highest resistant allele frequency occurred in the Central region and lowest frequencies were from the Northern and Southern regions. Resistance allele frequencies observed in 2014–2016 are nearly 1.5 times higher than those from pre-2012, indicating that resistance profiles can change over time. Regular monitoring of the L1014F kdr mutation will help aid in operational decisions.

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First report of L1014F kdr mutation in Culex quinquefasciatus in Mexico

Insect Science ◽

10.1111/1744-7917.12218 ◽

2015 ◽

Vol 23 (6) ◽

pp. 829-834 ◽

Cited By ~ 6

Author(s):

Gustavo Ponce ◽

Iram P. Sanchez ◽

Selene M. García ◽

Jose M. Torrado ◽

Saúl Lozano-Fuentes ◽

...

Keyword(s):

Culex Quinquefasciatus ◽

Kdr Mutation ◽

First Report ◽

L1014f Kdr

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High-throughput approach to detection of knockdown resistance (kdr) mutation in mosquitoes, Culex quinquefasciatus, based on real-time PCR using single-labelled hybridisation probe/melting curve analysis

Pest Management Science ◽

10.1002/ps.2044 ◽

2010 ◽

Vol 67 (2) ◽

pp. 156-161 ◽

Cited By ~ 10

Author(s):

Manas Sarkar ◽

Indra Baruah ◽

Ravi B Srivastava ◽

Aparajita Borkotoki ◽

Indra Kumar Bhattacharyya

Keyword(s):

Real Time ◽

High Throughput ◽

Culex Quinquefasciatus ◽

Real Time Pcr ◽

Melting Curve ◽

Curve Analysis ◽

Melting Curve Analysis ◽

Kdr Mutation ◽

Knockdown Resistance ◽

Hybridisation Probe

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First Comprehensive Report of Conventional Insecticide Resistance Status of the Mosquito Culex quinquefasciatus Say (Diptera: Culicidae) in Saudi Arabia

10.21203/rs.3.rs-907877/v1 ◽

2021 ◽

Author(s):

Abdulwahab M. Hafez

Keyword(s):

Saudi Arabia ◽

Culex Quinquefasciatus ◽

Disease Transmission ◽

Integrated Vector Management ◽

West Nile Fever ◽

Pyrethroid Insecticides ◽

Low Resistance ◽

Vector Management ◽

Pirimiphos Methyl ◽

Moderate Resistance

Abstract Background The mosquito Culex quinquefasciatus Say is a vector of various fatal diseases including West Nile fever, filariasis, and Japanese encephalitis. The major approach in controlling Cx. quinquefasciatus to prevent associated disease transmission has focused on insecticides. However, because of overreliance on such measures, Cx. quinquefasciatus has developed resistance to these insecticides including organophosphates and pyrethroids. Methods We evaluated 10 commonly used conventional insecticides (five OPs and five pyrethroids) for toxicity/resistance in Cx. quinquefasciatus in adults and larvae in eight populations collected from the environs around Riyadh, Saudi Arabia. Results The LC50 values for the tested insecticides in adults did not differ significantly from those of a susceptible strain, except for bifenthrin, deltamethrin, cypermethrin, cyfluthrin, and fenitrothion against populations from Al-Nakhil, Al-Suwaidi, Al-Ghanemiya, Al-Masfa, and Al-Masanie regions. All Cx. quinquefasciatus adult populations exhibited susceptibility/low resistance to the tested organophosphates with resistance ratios of 0.23–0.80 for chlorpyrifos, 0.44–1.97 for malathion, 0.09–3.62 for fenitrothion, 0.05–2.10 for pirimiphos-methyl, and 0.11–0.93 for diazinon. The Cx. quinquefasciatus adult populations exhibited susceptibility/moderate resistance to the tested pyrethroids with resistance ratios of 0.59–2.56 for alpha-cypermethrin, 0.59–2.19 for bifenthrin, 0.60–7.07 for deltamethrin, 0.60–2.66 for cypermethrin, and 0.58–2.39 for cyfluthrin. In Cx. quinquefasciatus larva populations, susceptibility/low resistance to the tested organophosphates was observed with resistance ratios of 0.03–1.75 for chlorpyrifos, 0.19–3.42 for malathion, 0.11–2.78 for fenitrothion, and 0.08–1.15 for pirimiphos-methyl. Conclusions The susceptibility/low resistance of Cx. quinquefasciatus adults to OP and pyrethroid insecticides suggests that they still have good potency against the adults of this species in Riyadh, Saudi Arabia. These results provide a baseline for decision-making in integrated vector management programs for Cx. quinquefasciatus.

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Factors affecting resistance to insecticides in house-flies, Musca domestica L. (Diptera: Muscidae). II. Close linkage on autosome 2 between an esterase and resistance to trichlorphon and pyrethroids

Bulletin of Entomological Research ◽

10.1017/s0007485300011342 ◽

1984 ◽

Vol 74 (2) ◽

pp. 197-206 ◽

Cited By ~ 21

Author(s):

R. M. Sawicki ◽

A. L. Devonshire ◽

A. W. Farnham ◽

Kate E. O'Dell ◽

G. D. Moores ◽

...

Keyword(s):

Musca Domestica ◽

Pyrethroid Resistance ◽

Resistance Mechanism ◽

Mechanisms Of Resistance ◽

Pyrethroid Insecticides ◽

Factors Affecting ◽

House Flies ◽

Resistant Strains ◽

Moderate Resistance ◽

Weak Resistance

AbstractWidespread slight pyrethroid-resistance in Musca domestica L. on animal farms in southern England was correlated with strong resistance to trichlorphon and to malathion, and with the presence of an esterase, E0·39, detected by electrophoresis. In the laboratory, the frequency of E0·39 increased in response to selection with either pyrethroids or trichlorphon. Genetic analysis confirmed that this esterase, controlled by a gene on autosome 2, was closely linked with moderate resistance to trichlorphon and malathion and weak resistance to pyrethroids. When autosome 2 with the gene for E0·39 was introduced into a strain homozygous for the resistance mechanism super-kdr, resistance to pyrethroids increased by a factor equivalent to the weak resistance conferred by autosome 2 with E0·39 alone. Homozygosity for both mechanisms of resistance, and E0·39, was obtained by selecting the progeny of this cross with permethrin alone, permethrin and trichlorphon, or DDT and trichlorphon, demonstrating that very strong pyrethroid resistance can be achieved through the use of non-pyrethroid insecticides. E0·39 was absent from insecticide-resistant strains of M. domestica from Denmark but was present in several multi-resistant strains from other European countries.

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Novel CONCOMITANT mutations L932F and I936V in the Voltage-Gated Sodium Channel and Its Association With Pyrethroid Resistance in Culex quinquefasciatus (Diptera: Culicidae)

Journal of Medical Entomology ◽

10.1093/jme/tjaa238 ◽

2020 ◽

Author(s):

Masaaki Sugiura ◽

Fumiko Kimoto ◽

Kentaro Itokawa ◽

Shinji Kasai

Keyword(s):

Cytochrome P450 ◽

Sodium Channel ◽

Culex Quinquefasciatus ◽

Pyrethroid Resistance ◽

Cross Resistance ◽

Kdr Mutation ◽

Voltage Gated Sodium Channel ◽

Important Species ◽

Voltage Gated ◽

Brazilian Strain

Abstract Highly residual pyrethroids such as permethrin have been used for controlling mosquitoes that transmit infectious diseases. However, the selective pressure from such insecticides may result in cross-resistance against other pyrethroids used for household insecticides. In this study, we investigated the susceptibility of Culex quinquefasciatus Say collected from Brazil and Myanmar to permethrin in addition to four types of household pyrethroids. Both strains exhibited high resistance against all pyrethroids tested, indicating cross-resistance. Furthermore, we detected the knockdown resistance (kdr) mutations L932F+I936V in the voltage-gated sodium channel gene (VGSC) in the Brazilian strain. Notably, the L932F+I936V haplotype has previously been observed in in silico data, but it should be detected not directly from living insects. In comparison, a common kdr mutation, L1014F, was detected from the Myanmar strain. Although L1014F was also detected from the Brazilian strain, the allele frequency was too low to affect resistance. Both strains harbored the resistance-associated haplotypes of the cytochrome P450 gene, CYP9M10. The Brazilian strain demonstrated comparable resistance against pyrethroids as that of the Myanmar strain even when a cytochrome P450 inhibitor, piperonyl butoxide was added to the bioassay. Our results suggested that the L932F+I936V mutations confer the Brazilian strain of Cx. Quiquefasciatus with resistance at a comparable level to that conferred by the well-recognized kdr mutation L1014F in the Myanmar strain. The identification of unexplored mutations may improve the diagnosis and understanding of resistance of this medically important species.

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