scholarly journals Effect of the synergists piperonyl butoxide and DEF in deltamethrin resistance on strains of Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae)

2000 ◽  
Vol 29 (4) ◽  
pp. 749-755 ◽  
Author(s):  
Irineu Lorini ◽  
David J. Galley
Keyword(s):  
Filter Paper ◽  
Lethal Dose ◽  
Research Tool ◽  
Piperonyl Butoxide ◽  
Rhyzopertha Dominica ◽  
Important Research ◽  
Mechanisms Of Resistance ◽  
Deltamethrin Resistance ◽  
Resistant Strains ◽  
Tributyl Phosphorotrithioate

Synergists are an important research tool in the laboratory to help to determine the mechanisms of resistance involved in a particular population. This kind of investigation has produced valuable results in understanding resistance to pesticides. The ability of these compounds in suppressing deltamethrin resistance on four strains of Rhyzopertha dominica (F.) was evaluated under laboratory conditions. Two susceptible strains, obtained from the eighth generation in laboratory without any selection were tested; other two resistant strains consisted in the fifth deltamethrin selected generation. Each strain was bioassayed on filter paper impregnated with deltamethrin associated with a synergist in different proportions, following the methods recommended by FAO for assessing resistance. The synergists tested were piperonyl butoxide (PBO) and S,S,S-tributyl phosphorotrithioate (DEF), at the following proportions 1:0, 1:5, 1:10 and 1:15 of deltamethrin and the synergist, respectively. Both synergists showed a role in blocking enzymes involved in detoxifying deltamethrin. PBO conferred up to 27 times higher toxicity ratios in the resistant strains than in the susceptible ones. DEF was less effective in reducing the lethal dose of deltamethrin with ratios up to five times.

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.

Cross resistance spectra and effects of synergists in insecticide-resistant strains of Lucilia cuprina (Diptera: Calliphoridae)

1994 ◽  
Vol 84 (3) ◽  
pp. 355-360 ◽  
Author(s):  
A.C. Kotze ◽  
N. Sales
Keyword(s):  
Piperonyl Butoxide ◽  
Lucilia Cuprina ◽  
Cross Resistance ◽  
Resistance Factors ◽  
Deltamethrin Resistance ◽  
Detoxification Systems ◽  
Australian Sheep ◽  
Resistant Strains ◽  
Level Resistance

AbstractCross-resistance spectra were determined in strains of the Australian sheep blowfly, Lucilia cuprina (Wiedemann), which had been pressured for several years in the laboratory with diflubenzuron, butacarb or deltamethrin. Each strain was highly resistant to its selecting chemical (resistance factors > 1000-fold), however, cross-resistance levels were variable and often low. In particular, strains selected with diflubenzuron and butacarb showed very little resistance to deltamethrin (resistance factors <7-fold). Each strain showed resistance levels to diazinon only slightly higher than the highest levels currently detected in field strain larvae. Piperonyl butoxide and triphenyl phosphate significantly synergized each pressured strain with its selecting chemical, suggesting the involvement of both monooxygenases and esterases in the observed resistances. Synergism ratios in each case were greater with piperonyl butoxide. The lack of any alteration in in vitro acetylcholinesterase sensitivity to butacarb inhibition in the butacarb-selected strain, and only low level resistance to DDT in the deltamethrin-selected strain, provided no evidence for target-site insensitivities in these strains. The low-moderate levels of cross-resistance therefore imply the existence of qualitative differences in the detoxification systems in each strain.

Will nanomedicine deliver on its promise of changing therapeutics or remain an interesting and important research tool in cell biology and physiology?

2013 ◽  
Vol 454 (1) ◽  
pp. 530-531 ◽  
Author(s):  
Richard Kirsh ◽  
Steve Hood ◽  
Chris Brook ◽  
Aidan Gilmartin ◽  
Philip Dell’orco ◽  
...  
Keyword(s):  
Cell Biology ◽  
Research Tool ◽  
Important Research

scholarly journals Mobility of Stored Product Beetles after Exposure to a Combination Insecticide Containing Deltamethrin, Methoprene, and a Piperonyl Butoxide Synergist Depends on Species, Concentration, and Exposure Time

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 151 ◽  
Author(s):  
Frank H. Arthur ◽  
Christos G. Athanassiou ◽  
W. Robert Morrison
Keyword(s):  
Exposure Time ◽  
General Pattern ◽  
Sitophilus Oryzae ◽  
Piperonyl Butoxide ◽  
Rhyzopertha Dominica ◽  
Cryptolestes Ferrugineus ◽  
Curve Fit ◽  
Exposure Interval ◽  
Grain Protectant ◽  
The Relationship

Adults of Rhyzopertha dominica (F.), the lesser grain borer, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, and Sitophilus oryzae (L.), the rice weevil, were exposed for 1, 24, and 72 h on wheat treated with concentrations of 0% (untreated controls) to 100% of the proposed label rate of an experimental formulation of deltamethrin + Methoprene + piperonyl butoxide synergist. Movement and velocity of movement were assessed after each exposure time using a camera-based monitoring system (Ethovision®). Movement of R. dominica decreased with increasing concentration and exposure time, so that movement had virtually ceased at the 48 and 72 h exposures. Cryptolestes ferrugineus was less susceptible compared to R. dominica, but there was still a general pattern of decreased movement and velocity of movement with increasing concentration and exposure time. Sitophilus oryzae was the least susceptible species, with less differences at the 1 h exposure interval compared to the other two species, but after 24–72 h, the patterns of declining movement and velocity were apparent as the concentration increased. Data were analyzed using curve-fit equations to show the relationship between concentration and exposure time for each species. Results show that the Ethovison system can be used to assess the sub-lethal effects of exposure to grain protectant insecticides and elucidate behavioral variation between different stored product insects.

scholarly journals Preliminary Study on the Differences in Hydrocarbons Between Phosphine-Susceptible and -Resistant Strains of Rhyzopertha dominica (Fabricius) and Tribolium castaneum (Herbst) Using Direct Immersion Solid-Phase Microextraction Coupled with GC-MS

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1565
Author(s):  
Ihab Alnajim ◽  
Manjree Agarwal ◽  
Tao Liu ◽  
Beibei Li ◽  
Xin Du ◽  
...  
Keyword(s):  
Cuticular Hydrocarbons ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Rhyzopertha Dominica ◽  
Gas Chromatography Mass Spectrometry ◽  
Stored Grain ◽  
Phosphine Resistance ◽  
Significant Difference ◽  
Resistant Strains ◽  
Direct Immersion

Phosphine resistance is a worldwide issue threatening the grain industry. The cuticles of insects are covered with a layer of lipids, which protect insect bodies from the harmful effects of pesticides. The main components of the cuticular lipids are hydrocarbon compounds. In this research, phosphine-resistant and -susceptible strains of two main stored-grain insects, T. castaneum and R. dominica, were tested to determine the possible role of their cuticular hydrocarbons in phosphine resistance. Direct immersion solid-phase microextraction followed by gas chromatography-mass spectrometry (GC-MS) was applied to extract and analyze the cuticular hydrocarbons. The results showed significant differences between the resistant and susceptible strains regarding the cuticular hydrocarbons that were investigated. The resistant insects of both species contained higher amounts than the susceptible insects for the majority of the hydrocarbons, sixteen from cuticular extraction and nineteen from the homogenized body extraction for T. castaneum and eighteen from cuticular extraction and twenty-one from the homogenized body extraction for R. dominica. 3-methylnonacosane and 2-methylheptacosane had the highest significant difference between the susceptible and resistant strains of T. castaneum from the cuticle and the homogenized body, respectively. Unknown5 from the cuticle and 3-methylhentriacontane from the homogenized body recorded the highest significant differences in R. dominica. The higher hydrocarbon content is a key factor in eliminating phosphine from entering resistant insect bodies, acting as a barrier between insects and the surrounding phosphine environment.

scholarly journals Antimicrobial Resistance of Listeria monocytogenes Strains Isolated from Humans in France

2010 ◽  
Vol 54 (6) ◽  
pp. 2728-2731 ◽  
Author(s):  
A. Morvan ◽  
C. Moubareck ◽  
A. Leclercq ◽  
M. Hervé-Bazin ◽  
S. Bremont ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Antimicrobial Resistance ◽  
Resistant Strain ◽  
Temporal Evolution ◽  
Acquired Resistance ◽  
Mechanisms Of Resistance ◽  
Resistant Strains ◽  
High Level ◽  
Level Resistance ◽  
Microbiological Surveillance

ABSTRACT Susceptibility to antibiotics of 4,816 clinical L. monocytogenes strains isolated since 1926 was studied, and the temporal evolution of susceptibility to antibiotics was analyzed through several decades. The mechanisms of resistance in each resistant strain were studied. The prevalence of resistant strains was estimated at 1.27% among isolates from humans. Resistance to tetracyclines+ and fluoroquinolones was more common and has recently emerged. Although acquired resistance in clinical L. monocytogenes did not implicate clinically relevant antibiotics, the possibility of resistance gene transfers, the description of the first clinical isolate with high-level resistance to trimethoprim, and the recent increase in penicillin MICs up to 2 μg/ml reinforce the need for microbiological surveillance.

scholarly journals Antigiardial Effect of Kramecyne in Experimental Giardiasis

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Leticia Eligio-García ◽  
Elida Pontifez-Pablo ◽  
Salúd Pérez-Gutiérrez ◽  
Enedina Jiménez-Cardoso
Keyword(s):  
Side Effects ◽  
High Efficiency ◽  
Morphological Changes ◽  
Lethal Dose ◽  
Expression Of Genes ◽  
Antigiardial Activity ◽  
Resistant Strains ◽  
Polymerase Chain

A variety of drugs are used in giardiasis treatment with different levels of efficiency, presence of side effects, and even formation of resistant strains, so that it is important to search new only-one-dose treatments with high efficiency and less side effects. Kramecyne, an anti-inflammatory compound isolated from methanolic extract ofKrameria cytisoides, does not present toxicity, even at doses of 5,000 mg/kg. The objective was to determine the antigiardial effect of kramecyne overGiardia intestinalis in vitroandin vivoand analyze the expression of genes ERK1, ERK2, and AK on kramecyne treated trophozoites by Real Time Polymerase Chain Reaction (RTPCR). The median lethal dose (LD50) was 40 μg/mL and no morphological changes were observed by staining with blue trypan and light microscopy; experimental gerbil infection was eliminated with 320 μg/Kg of weight. After treatment there were no differences between intestines from treated and untreated gerbils. Kramecyne did not have significant effect over ERK1 and AK, but there are differences in ERK2 expression (p=0.04). Results show antigiardial activity of kramecyne; however the mode of action is still unclear and the evaluation of ultrastructural damage and expressed proteins is an alternative of study to understand the action mechanism.

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