scholarly journals Studies on organophosphate-resistance and esterase activity in the mosquitoes of the Culex pipiens group. I.

1970 ◽  
Vol 21 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Kazuo Yasutomi
Keyword(s):  
Esterase Activity ◽  
Culex Pipiens ◽  
Organophosphate Resistance ◽  
Group I

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.

Comparative study of resistance to organophosphate and carbamate insecticides in four strains of the Culex pipiens L. complex (Diptera: Culicidae)

1986 ◽  
Vol 76 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Z. H. Tang ◽  
R. J. Wood
Keyword(s):  
Esterase Activity ◽  
Culex Pipiens ◽  
Larval Instar ◽  
Piperonyl Butoxide ◽  
Lower Sensitivity ◽  
Pyrethroid Insecticides ◽  
Carbamate Insecticides ◽  
High Production ◽  
Resistant Strains ◽  
General Esterase

AbstractFive strains of Culex pipiens L. (four resistant and one susceptible) were compared at the fourth larval instar for tolerance to organophosphate, carbamate and pyrethroid insecticides, with and without the addition of three synergists (piperonyl butoxide, triphenyl phosphate (TPP) and S, S, S-tributyl phosphorotrithiote (TBPT)). The DAR/D strain from Tanzania showed the highest levels and broadest range of resistance (temephos 37 ×, malathion 579×, propoxur 3032× and permethrin 100×). A strain from Rangoon and two from France (S54, BLEUET) showed lower resistance, restricted to organophosphates. Temephos and malathion resistance in the RANGOON strain was strongly inhibited by TBPT but not by TPP or piperonyl butoxide. Temephos and permethrin resistance in the DAR/D strain was slightly inhibited by TBPT and permethrin resistance by piperonyl butoxide. The DAR/D, RANGOON and CfCA (susceptible) strains were also compared for general esterase activity and phosphatase activity, both of which were higher in the resistant strains. It is concluded that resistance in RANGOON is associated with high production of an esterase sensitive to inhibition by TBPT but with little or no sensitivity to TPP, resembling but not identical in properties with the enzyme in strain S54 investigated earlier. Resistance in DAR/D was also associated with some increase in esterase activity, but the basis of resistance was different from that in S54 and RANGOON, having a much lower sensitivity to inhibition by TBPT.

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

THE ACTIVATION AND INHIBITION OF TRYPSIN BY QUATERNARY AMMONIUM COMPOUNDS

1961 ◽  
Vol 39 (7) ◽  
pp. 1193-1204 ◽  
Author(s):  
Brian C. W. Hummel
Keyword(s):  
Quaternary Ammonium ◽  
Substrate Concentration ◽  
Esterase Activity ◽  
Quaternary Ammonium Compounds ◽  
High Concentration ◽  
Group I ◽  
Group Ii ◽  
Fold Activation ◽  
Ammonium Compounds

The effect of a variety of quaternary ammonium compounds upon the esterase activity of trypsin was investigated. Both activation and inhibition were observed; some compounds activated at low, but inhibited at higher, concentrations (group I), while others activated at high concentration (group II). Tetramethyl-, tetraethyl-, and tetra-n-propyl-ammonium bromides fell in group II, whereas tetra-n-butylammonium iodide fell in group I (50% inhibition at 0.52 mmolar). Dimethonium, pentamethonium, hexamethonium (2.25-fold activation at 0.08 M), heptamethonium, and decamethonium bromides belonged to group II. Activation by decamethonium bromide was greater at pH 7.2 than at pH 8.1 and was abolished by increasing the substrate concentration. Trypsin in the presence of 0.02 M calcium was activated only 11% by 0.03 M decamethonium bromide. An hypothesis offering a possible explanation of these observations is presented.

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