Mechanisms of Insecticide Resistance in a Strain of Cat Fleas (Siphonaptera: Pulicidae)

Possible mechanisms of insecticide resistance were investigated in a known-resistant strain of cat fleas, Ctenocephalides felis Bouché. In the acetylcholinesterase study, ability of two insecticides, propoxur and chlorpyrifosoxon, to inhibit the activity of the enzyme was investigated using the Ellman method. In both cases, at least twice the amount of insecticide was required for 50% enzyme inhibition in the resistant fleas vs the susceptible fleas. Additionally, there was a significant difference in levels of glutathione transferase in the resistant strain of fleas compared with the susceptible strain. These results indicate that both insensitive acetylcholinesterase and detoxification via glutathione transferase conjugation may be involved in the insecticide resistance mechanisms of this strain of fleas.

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Genetic linkage between malathion and dieldrin resistance in Anopheles arabiensis

Canadian Journal of Genetics and Cytology ◽

10.1139/g84-102 ◽

1984 ◽

Vol 26 (6) ◽

pp. 646-650 ◽

Cited By ~ 3

Author(s):

J. D. Lines ◽

C. F. Curtis

Keyword(s):

Linkage Disequilibrium ◽

Insecticide Resistance ◽

Resistance Genes ◽

Recombination Rate ◽

Genetic Linkage ◽

Anopheles Arabiensis ◽

Backcross Progeny ◽

Resistance Mechanisms ◽

Susceptible Strain ◽

Insecticide Exposure

A strain of Anopheles arabiensis resistant to both malathion and dieldrin was crossed and backcrossed to a susceptible strain. The progeny were tested on each insecticide in turn. Less than 50% mortality in the second insecticide exposure among the backcross progeny indicated linkage between the resistance genes. In a backcross of A. gambiae × A. arabiensis hybrids a recombination rate of 7.5% was observed. A Y-translocation strain of A. arabiensis showed less than 2.8% recombination between the resistance genes. It is impossible to confirm the genotype of apparent recombinants using existing stocks, but the two resistance mechanisms are biochemically distinguishable. If the two genes are very closely linked, linkage disequilibrium could influence the consequences of switching to malathion spraying after dieldrin resistance has evolved.Key words: Anopheles, linkage, insecticide resistance, translocation.

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First Report of Biochemical Mechanisms of Insecticide Resistance in the Field Population of Culex pipiens (Diptera: Culicidae) From Sari, Mazandaran, North of Iran

Journal of Arthropod-Borne Diseases ◽

10.18502/jad.v13i4.2234 ◽

2020 ◽

Author(s):

Seyed Hassan Nikookar ◽

Mahmoud Fazeli-Dinan ◽

Seyyed Payman Ziapour ◽

Fatemeh Ghorbani ◽

Yaser Salim-Abadi ◽

...

Keyword(s):

Insecticide Resistance ◽

Culex Pipiens ◽

Pyrethroid Resistance ◽

Cytochrome P450s ◽

Field Population ◽

Susceptible Strain ◽

Laboratory Population ◽

Significant Difference ◽

North Of Iran ◽

The Mean

Background: Culex pipiens play an important role in transmission of infectious diseases. Vector control by chemical pesticides, leads inevitably to resistance development. Understanding the underlying resistance mechanisms can help improve the control programmes and insecticide resistance management. Methods: The total contents of cytochrome p450s and the activities of glutathione S-transferases, alpha- and beta-esterases and inhibition rates of acetylcholine esterase (by propoxur) were measured in the field population of Cx. pipiens collected from Sari County, North of Iran, in 2016 and the results were compared with those of the laboratory susceptible strain according to the biochemical assay methods of WHO for adult mosquitoes. Independent sample t-test was used to compare the mean values of enzyme activities/contents between filed and laboratory susceptible popula-tions. Results: The enzyme ratio of cytochrome p450s, alpha- and beta-esterases in the field population was 2.07, 3.72 and 1.36 respectively when compared with the results of the laboratory population. Although not statistically significant, the mean GSTs activities in the field population was marginally less than the laboratory population (ER=0.92). Ace-tylcholinesterase was insensitive to propoxur in 62.82% of the individuals of the tested field population. There was a significant difference (P< 0.05) between all values of the activities/contents of the enzyme in the field population except for GSTs compared with the laboratory susceptible strain. The highest enzyme activity was related to alpha esterase. Conclusion: The present study showed a range of metabolic mechanisms, comprising p450s and esterases combined with target site insensitivity of AChE, contributing to organophosphate, carbamate and pyrethroid resistance in the field population of Cx. pipiens.

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Biochemical and molecular resistance mechanisms to DDT and some pyrethroid insecticides in vector of West Nile virus, Culex pipiens

10.21203/rs.3.rs-17900/v1 ◽

2020 ◽

Author(s):

Yaser Salim-Abadi ◽

Hassan Vatandoost ◽

Mohammad Ali Oshaghi ◽

Mohamad Reza Abai ◽

Ahmad Ali Enayati ◽

...

Keyword(s):

West Nile Virus ◽

Insecticide Resistance ◽

Sodium Channel ◽

Resistant Strain ◽

Culex Pipiens ◽

Molecular Study ◽

Resistance Mechanisms ◽

West Nile ◽

Pyrethroid Insecticides ◽

Channel Gene

Abstract Objectives : Culex pipiens complex act as an important vector of several vector-borne diseases such as filariasis, West Nile virus, Japanese encephalitis and bird malaria. This study was designed in order to clarify the molecular and biochemical resistance mechanisms in Cx. pipiens to DDT and some pyrethroid insecticides from Tehran, capital of Iran.Materials and methods Profile activities of α- and ß-esterases, Mixed Function Oxidase (MFO), Glutathione-S Transferase (GST), were tested for Cx .pipiens strain with resistance ratio of 85.75 to Lambdacyhalothrin and also about DDT resistant strain in comparison with Lab strain. In the present research a molecular study also performed on both lambdacyhalothrin and DDT. Resistant strains for detection of the mutation in the sodium channel gene which is associated with kdr insecticide resistance to pyrethroid and DDT were used . For comparison of average between two groups T test were used.Results Our finding showed that there are significant different (p<0.05) between the mean activity of α-, ß-esterases and (MFO), in both lambacyhalothrin and DDT resistant strain in comparison with Lab-Strain, but there are no significant difference (p>0.05) about (GST) in the both strain in comparison with Lab-Strain. Molecular study for detection of L1014F or L1014S mutation in sodium channel gene showed lack of the mutation responsible for insecticide resistance to pyrethroid and DDT.Discussion This study showed that the resistance to pyrethroids and DDT in the Cx pipiens is enzymatic, but not targets site insensitivity of sodium channel gene.Conclusion Findings of this research could provide a clue for logical operations of future chemical control program.

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Efficacy of Novel Rifamycin Derivatives against Rifamycin-Sensitive and -Resistant Staphylococcus aureus Isolates in Murine Models of Infection

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01087-05 ◽

2006 ◽

Vol 50 (11) ◽

pp. 3658-3664 ◽

Cited By ~ 12

Author(s):

David M. Rothstein ◽

Ronald S. Farquhar ◽

Klari Sirokman ◽

Karen L. Sondergaard ◽

Charles Hazlett ◽

...

Keyword(s):

Staphylococcus Aureus ◽

Resistant Strain ◽

Susceptible Strain ◽

Model Systems ◽

Infection Model ◽

Bacterial Titer ◽

Significant Difference ◽

New Chemical Entities ◽

Systemic Infections

ABSTRACT Novel rifamycins (new chemical entities [NCEs]) having MICs of 0.002 to 0.03 μg/ml against Staphylococcus aureus and retaining some activity against rifampin-resistant mutants were tested for in vivo efficacy against susceptible and rifampin-resistant strains of S. aureus. Rifalazil and rifampin had a 50% effective dose (ED50) of 0.06 mg/kg of body weight when administered as a single intravenous (i.v.) dose in a murine septicemia model against a susceptible strain of S. aureus. The majority of NCEs showed efficacy at a lower i.v. dose (0.003 to 0.06 mg/kg). In addition, half of the NCEs tested for oral efficacy had ED50s in the range of 0.015 to 0.13 mg/kg, i.e., lower or equivalent to the oral ED50s of rifampin and rifalazil. NCEs were also tested in the septicemia model against a rifampin-resistant strain of S. aureus. Twenty-four of 169 NCEs were efficacious when administered as a single oral dose of 80 mg/kg. These NCEs were examined in the murine thigh infection model against a susceptible strain of S. aureus. Several NCEs dosed by intraperitoneal injection at 0.06 mg/kg caused a significant difference in bacterial titer compared with placebo-treated animals. No NCEs showed efficacy in the thigh model against a highly rifampin-resistant strain. However, several NCEs showed an effect when tested against a partially rifampin-resistant strain. The NCEs having a 25-hydroxyl moiety were more effective as a group than their 25-O-acetyl counterparts. These model systems defined candidate NCEs as components of potential combination therapies to treat systemic infections or as monotherapeutic agents for topical applications.

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Insecticide resistance status of malaria vectors Anopheles gambiae (s.l.) of southwest Burkina Faso and residual efficacy of indoor residual spraying with microencapsulated pirimiphos-methyl insecticide

Parasites & Vectors ◽

10.1186/s13071-020-04563-8 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Dieudonné Diloma Soma ◽

Barnabas Zogo ◽

Domonbabele François de Sales Hien ◽

Aristide Sawdetuo Hien ◽

Didier Alexandre Kaboré ◽

...

Keyword(s):

Insecticide Resistance ◽

Burkina Faso ◽

Anopheles Gambiae ◽

Local Population ◽

Residual Activity ◽

Indoor Residual Spraying ◽

Susceptible Strain ◽

Malaria Vectors ◽

Pirimiphos Methyl ◽

Residual Efficacy

Abstract Background The rapid spread of insecticide resistance in malaria vectors and the rebound in malaria cases observed recently in some endemic areas underscore the urgent need to evaluate and deploy new effective control interventions. A randomized control trial (RCT) was conducted with the aim to investigate the benefit of deploying complementary strategies, including indoor residual spraying (IRS) with pirimiphos-methyl in addition to long-lasting insecticidal nets (LLINs) in Diébougou, southwest Burkina Faso. Methods We measured the susceptibility of the Anopheles gambiae (s.l.) population from Diébougou to conventional insecticides. We further monitored the efficacy and residual activity of pirimiphos-methyl on both cement and mud walls using a laboratory susceptible strain (Kisumu) and the local An. gambiae (s.l.) population. Results An. gambiae (s.l.) from Diébougou was resistant to DDT, pyrethroids (deltamethrin, permethrin and alphacypermethrin) and bendiocarb but showed susceptibility to organophosphates (pirimiphos-methyl and chlorpyrimiphos-methyl). A mixed-effect generalized linear model predicted that pirimiphos-methyl applied on cement or mud walls was effective for 210 days against the laboratory susceptible strain and 247 days against the local population. The residual efficacy of pirimiphos-methyl against the local population on walls made of mud was similar to that of cement (OR = 0.792, [0.55–1.12], Tukey’s test p-value = 0.19). Conclusions If data on malaria transmission and malaria cases (as measured trough the RCT) are consistent with data on residual activity of pirimiphos-methyl regardless of the type of wall, one round of IRS with pirimiphos-methyl would have the potential to control malaria in a context of multi-resistant An. gambiae (s.l.) for at least 7 months.

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Polygenic and single gene responses to selection for resistance to diazinon in Lucilia cuprina.

Genetics ◽

10.1093/genetics/130.3.613 ◽

1992 ◽

Vol 130 (3) ◽

pp. 613-620 ◽

Cited By ~ 6

Author(s):

J A McKenzie ◽

A G Parker ◽

J L Yen

Keyword(s):

Resistant Strain ◽

Single Gene ◽

Natural Populations ◽

Susceptible Strain ◽

Selection Line ◽

Base Population ◽

Gene Response ◽

Biochemical Profiles ◽

Resistant Strains ◽

Selection For

Abstract Following mutagenesis with ethyl methanesulfonate, selection in a susceptible strain with a concentration of the insecticide diazinon (0.0004%, w/v) above that required to kill 100% of the susceptible strain, the LC100 of that strain, resulted in a single gene response. The resultant four mutant resistant strains have equivalent physiological, genetical and biochemical profiles to a diazinon-resistant strain derived from a natural population and homozygous for the Rop-1 allele. Modification of the microsomal esterase E3 is responsible for resistance in each case. The Rop-1 locus maps approximately 4.4 map units proximal to bu on chromosome IV. Selection within the susceptible distribution, at a concentration of diazinon [0.0001% (w/v)] less than the LC100, resulted in a similar phenotypic response irrespective of whether the base population had been mutagenized. The responses were polygenically based, unique to each selection line and independent of Rop-1. The relevance of the results to selection for insecticide resistance in laboratory and natural populations is discussed.

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Multiple insecticide resistance mechanisms involving metabolic changes and insensitive target sites selected in anopheline vectors of malaria in Sri Lanka

Malaria Journal ◽

10.1186/1475-2875-7-168 ◽

2008 ◽

Vol 7 (1) ◽

pp. 168 ◽

Cited By ~ 50

Author(s):

M Devika B Perera ◽

Janet Hemingway ◽

SHP Parakrama Karunaratne

Keyword(s):

Sri Lanka ◽

Insecticide Resistance ◽

Resistance Mechanisms ◽

Metabolic Changes ◽

Target Sites

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THE DIFFERENTIAL RESPONSE OF STRAINS OF WILD CARROT TO 2,4-D AND RELATED HERBICIDES

Canadian Journal of Plant Science ◽

10.4141/cjps63-052 ◽

1963 ◽

Vol 43 (3) ◽

pp. 255-262 ◽

Cited By ~ 41

Author(s):

C. W. Whitehead ◽

C. M. Switzer

Keyword(s):

Resistant Strain ◽

Differential Response ◽

Susceptible Strain ◽

Severe Injury ◽

Radicle Growth ◽

Cotyledon Stage ◽

Wild Carrot

Studies were conducted on the effect of 2,4-D and some related herbicides on a susceptible and a resistant strain of wild carrot (Daucus corota L.). When treated with 2,4-D, 4-(2,4-DB) or 4-(MCPB), plants of the susceptible strain died within a few weeks while those of die resistant strain recovered after showing severe injury symptoms. Treatment with 2,4,5-T or silvex killed both the susceptible and resistant strains.Seeds of the two strains, placed in various concentrations of 2,4-D, showed no differences in germination or radicle growth after 7 days. However, sprays of 2,4-D on seedlings just after emergence produced the differential response. Resistance appeared to develop between germination and the cotyledon stage of growth.There were no differences in the effect of 2,4-D on the respiration of whole tissue of the susceptible and resistant wild carrots.

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