New Esterases Amplification Involved in Organophosphate Resistance in Culex Pipiens Mosquitoes from Tunisia

2016 ◽  
Vol 2 (12) ◽  
pp. 1-2
Author(s):  
Ahmed Tabbabi ◽  
Jaber Daaboub ◽  
Ali Laamari
Keyword(s):  
Culex Pipiens ◽  
Organophosphate Resistance

Carbamate and organophosphate resistance in Culex pipiens L. (Diptera: Culicidae) in southern France and the significance of Est-3A

1984 ◽  
Vol 74 (4) ◽  
pp. 677-687 ◽  
Author(s):  
R. J. Wood ◽  
N. Pasteur ◽  
G. Sinégre
Keyword(s):  
Culex Pipiens ◽  
Larval Instar ◽  
Piperonyl Butoxide ◽  
Southern France ◽  
Organophosphate Resistance ◽  
Metabolic Component ◽  
Carbamate Insecticides ◽  
Fourth Larval Instar ◽  
Resistant Strains ◽  
Tributyl Phosphorotrithioate

AbstractThree French strains of Culex pipiens L. were compared at the fourth larval instar for tolerance to organophosphate and carbamate insecticides, with and without the addition of synergists (the oxidase inhibitors piperonyl butoxide and CGA 84708) (a propynyl compound) and the carboxylesterase inhibitors triphenyl phosphate (TPP) and S,S,S-tributyl phosphorotrithioate (TBPT). The S54 strain was resistant to all the organophosphates tested (chlorpyrifos, malathion, monocrotophos and profenofos) compared to the susceptible LA VIS strain but only slightly tolerant to the two carbamates (carbaryl and naphthyl phenylcarbamate). The MAURIN strain was resistant to all the insecticides, including the carbamates, at a higher level. The action of chlorpyrifos and malathion on S54 was very strongly synergised by TBPT, less strongly by TPP and not at all by piperonyl butoxide. In fact, resistance was enhanced by piperonyl butoxide, as was resistance to monocrotophos and profenofos by CGA 84708. No synergist had much effect on the MAURIN strain, although TPP slightly increased the toxicity of malathion, and piperonyl butoxide and CGA 84708 slightly increased the toxicity of carbaryl. The toxic effect of carbaryl was also increased by the addition of extra acetone. Electrophoretic studies showed that the carboxylesterase enzyme coded by gene Est-20.64 (which is in linkage disequilibrium withEst-3A and acts as a marker for it) was absent from LA VIS but present in the resistant strains; but, whereas S54 was monomorphic for the gene, MAURIN was polymorphic (frequency 0·5). It is concluded that organophosphate resistance in S54 was due to detoxification by carboxylesterase wherease organophosphate and carbamate resistance in MAURIN had a strong non-metabolic component, possibly an insensitive acetylcholinesterase.

Biochemical characterization of the esterases A1 and B1 associated with organophosphate resistance in the Culex pipiens L. Complex

1987 ◽  
Vol 27 (2) ◽  
pp. 211-217 ◽  
Author(s):  
Didier Fournier ◽  
Jean-Marc Bride ◽  
Claude Mouches ◽  
Michel Raymond ◽  
Michel Magnin ◽  
...  
Keyword(s):  
Culex Pipiens ◽  
Biochemical Characterization ◽  
Organophosphate Resistance

Inheritance and activity of some esterases associated with organophosphate resistance in mosquitoes of the complex of Culex pipiens L. (Diptera: Cnlicidae)

1983 ◽  
Vol 73 (1) ◽  
pp. 153-170 ◽  
Author(s):  
F. Villani ◽  
G. B. White ◽  
C. F. Curtis ◽  
S. J. Miles
Keyword(s):  
Sri Lanka ◽  
High Intensity ◽  
Culex Pipiens ◽  
Resistance Mechanisms ◽  
Enzyme Assays ◽  
Resistance Level ◽  
Organophosphate Resistance ◽  
Esterase Pattern ◽  
Resistant Strains ◽  
Low Activity

AbstractEighteen strains of the complex of Culex pipiens L. from Africa, Asia and Europe were bioassayed for resistance to chlorpyrifos and electro-phoresed and stained for esterases. Susceptible strains showed only low activity esterase bands. The resistant strains of C. quinquefasciatus Say from hot countries (Liberia, Nigeria, Sri Lanka, Tanzania, Thailand) all showed the same two high intensity esterase bands (Rm 0·60 + 0·82). Different patterns of high esterase were found in resistant C. pipiens strains from cooler localities in Nairobi, Kenya (Rm 100), and Mont-pellier, France (Rm 0–50). Selection experiments on strains originally polymorphic for resistance and esterase pattern showed, without exception, that high esterase remained associated with resistance, and it is concluded that the association is almost certainly causal and not merely due to genetic linkage. The high intensity esterase bands were probably due to alleles of the loci Est-l, Est-2 and Est-3, separated by crossover distances of approximately 2·4 and 5·5 units, respectively. Strains monomorphic for what appeared to be the same high esterase pattern varied markedly in resistance level. Enzyme assays showed a direct relationship between levels of enzyme activity and resistance. Bioassays with fenthion and chlorpyrifos revealed differences in the relative resistance of C. quinquefasciatus from Colombo (Sri Lanka) and Dar-es-Salaam (Tanzania). Despite these differential degrees of cross-effectiveness, it is concluded that high intensity esterases are reliable indicators of organophosphate resistance in mosquitoes of the C. pipiens complex, although the possibility of other resistance mechanisms means that the lack of abnormally active esterases does not necessarily indicate the absence of resistance.

Est-2 and Est-3 polymorphisms in Culex pipiens L. from southern France in relation to organophosphate resistance

1981 ◽  
Vol 19 (5-6) ◽  
pp. 499-508 ◽  
Author(s):  
Nicole Pasteur ◽  
Gilbert Sin�gre ◽  
Andr� Gabinaud
Keyword(s):  
Culex Pipiens ◽  
Southern France ◽  
Organophosphate Resistance

Organophosphate resistance in vector Populations of the complex of Culex Pipiens L. (Diptera: Culicidae)

1981 ◽  
Vol 71 (1) ◽  
pp. 153-161 ◽  
Author(s):  
C. F. Curtis ◽  
N. Pasteur
Keyword(s):  
Sri Lanka ◽  
High Activity ◽  
Culex Quinquefasciatus ◽  
Urban Areas ◽  
Culex Pipiens ◽  
Single Gene ◽  
Field Studies ◽  
Susceptible Strain ◽  
Organophosphate Resistance ◽  
Closely Linked Group

AbstractResistance to chlorpyrifos and other commonly used organophosphate larvicides was found in Culex quinquefasciatus Say from several urban areas in Tanzania. Lower levels of resistance were found in laboratory strains of the complex of C. pipiens L. collected in Sri Lanka, Egypt, Liberia and Brazil. Crosses of the Tanzanian strains to a more susceptible strain gave results consistent with causation of the resistance by a single gene or closely linked group of genes. Electrophoresis of one of the Tanzanian stocks indicated two esterase bands of high activity. The resistance in Tanzania did not prevent larval killing by freshly sprayed chlorpyrifos, but it is suggested that a spraying would probably no longer remain effective for three months as reported in earlier field studies.

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