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Insects Dec 2021The codling moth, L. (Lepidoptera, Tortricidae), is a serious invasive pest of pome fruits. Currently, management mainly relies on the application of insecticides,...
The codling moth, L. (Lepidoptera, Tortricidae), is a serious invasive pest of pome fruits. Currently, management mainly relies on the application of insecticides, which have driven the development of resistance in the insect. Understanding the genetic mechanisms of insecticide resistance is of great significance for developing new pest resistance management techniques and formulating effective resistance management strategies. Using existing genome resequencing data, we performed selective sweep analysis by comparing two resistant strains and one susceptible strain of the insect pest and identified seven genes, among which, two (glycine receptor and glutamate receptor) were under strong insecticide selection, suggesting their functional importance in insecticide resistance. We also found that eight genes including , , , , and , are potentially involved in cross-resistance to azinphos-methyl and deltamethrin. Moreover, among several P450s identified as positively selected genes, , , and showed the highest expression level in larva compared to other stages tested, and also showed the highest expression level in midgut, supporting the roles they may play in insecticide metabolism. Our results provide several potential genes that can be studied further to advance understanding of complexity of insecticide resistance mechanisms in .
PubMed: 35055845
DOI: 10.3390/insects13010002 -
Ecology and Evolution Nov 2021Although insect herbivores are known to evolve resistance to insecticides through multiple genetic mechanisms, resistance in individual species has been assumed to...
Although insect herbivores are known to evolve resistance to insecticides through multiple genetic mechanisms, resistance in individual species has been assumed to follow the same mechanism. While both mutations in the target site insensitivity and increased amplification are known to contribute to insecticide resistance, little is known about the degree to which geographic populations of the same species differ at the target site in a response to insecticides. We tested structural (e.g., mutation profiles) and regulatory (e.g., the gene expression of and , AChE activity) differences between two populations (Vermont, USA and Belchow, Poland) of the Colorado potato beetle, in their resistance to two commonly used groups of insecticides, organophosphates, and carbamates. We established that Vermont beetles were more resistant to azinphos-methyl and carbaryl insecticides than Belchow beetles, despite a similar frequency of resistance-associated alleles (i.e., S291G) in the gene. However, the Vermont population had two additional amino acid replacements (G192S and F402Y) in the gene, which were absent in the Belchow population. Moreover, the Vermont population showed higher expression of and was less sensitive to AChE inhibition by azinphos-methyl oxon than the Belchow population. Therefore, the two populations have evolved different genetic mechanisms to adapt to organophosphate and carbamate insecticides.
PubMed: 34824806
DOI: 10.1002/ece3.8269 -
Environmental Toxicology and Chemistry Dec 2021We analyzed the reproductive success of eastern bluebirds (Sialia sialis) nesting in apple orchards and non-orchard nest-boxes in southern Ontario, Canada, from 1988 to...
We analyzed the reproductive success of eastern bluebirds (Sialia sialis) nesting in apple orchards and non-orchard nest-boxes in southern Ontario, Canada, from 1988 to 2018. Using data from 2397 nest-boxes monitored at 20 orchard sites and 52 non-orchard sites, we first modeled phenological parameters typically linked to climate change across both site types. We found that the first egg of each brood was laid significantly earlier in the season each year over our 31-year study. Clutch initiation occurred 4 days earlier in the spring in 2018 compared to 1988. Average clutch size in the first or second brood did not change significantly during our 31-year study; however, clutches were significantly smaller in orchards compared to non-orchards (0.10 ± 0.03 fewer eggs between sites). Nests built in orchards were also at 6.1-fold greater risk of parasitism and 2.1-fold greater risk of depredation than nests in non-orchards. After accounting for depredation and nest parasitism, hatching success was still significantly lower in orchards than in non-orchards. Overall, hatching success was 4%-5% lower in orchards. The probability of successfully fledging did not differ significantly between site types. In 2012, a ban on use of the organophosphate insecticide azinphos-methyl in orchards was enacted in Canada. We did not find a difference in hatching or fledging success in orchards after the ban. In our assessment of available data, we conclude that any pesticide effect on hatching success of eastern bluebirds in sprayed orchards is most likely the consequence of long-term exposure to dichlorodiphenyltrichloroethane (DDT) compounds in orchard soils and bioaccumulation in eggs rather than pesticides in use since regulation of DDT in the 1970s. Environ Toxicol Chem 2021;40:3369-3378. © 2021 Her Majesty the Queen in Right of Canada. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. Reproduced with the permission of the Minister of Environment and Climate Change Canada.
Topics: Animals; Ecosystem; Female; Malus; Ontario; Pesticides; Songbirds
PubMed: 34551148
DOI: 10.1002/etc.5218 -
Journal of Biomolecular Structure &... 2022In the present study, combining spectroscopic and molecular modeling techniques has been used to analyze azinphos-methyl binding properties, as an organophosphorus...
In the present study, combining spectroscopic and molecular modeling techniques has been used to analyze azinphos-methyl binding properties, as an organophosphorus pesticide, to bovine serum albumin. The quenching interaction of azinphos-methyl with bovine serum albumin was investigated in an appropriate physiological state (pH = 7.4). Fluorescence spectroscopy, UV-visible spectroscopy, circular dichroism (CD) and Fourier transform infrared spectroscopy (FTIR). Findings showed differences in the secondary protein structure microenvironment following interaction with azinphos-methyl. The results from spectroscopic experiments suggest that azinphos-methyl binds to bovine serum albumin residues with a binding constant in the range of 0.099 10-0.209 10 in one binding site (Tyr 160). The experimental results are supported by computational techniques such as docking using a bovine serum albumin crystal model. The results show that azinphos-methyl is linked to the site I of bovine serum albumin (in subdomain IB), and the result was in accordance with the experimental result. Based on the negative ΔG°, ΔH° and ΔS° values, the binding between azinphos-methyl and bovine serum albumin was spontaneous, and docking studies confirmed hydrogen bonding and van der Waals forces between them.Communicated by Ramaswamy H. Sarma.
Topics: Serum Albumin, Bovine; Molecular Docking Simulation; Azinphosmethyl; Organophosphorus Compounds; Pesticides; Binding Sites; Spectrometry, Fluorescence; Circular Dichroism; Spectroscopy, Fourier Transform Infrared; Protein Binding; Thermodynamics
PubMed: 34427168
DOI: 10.1080/07391102.2021.1968954 -
ALTEX 2022The photomotor response (PMR) of zebrafish embryos, a light pulse-triggered undirected movement, is known to be altered by neuroactive chemicals. Here, we developed an...
The photomotor response (PMR) of zebrafish embryos, a light pulse-triggered undirected movement, is known to be altered by neuroactive chemicals. Here, we developed an approach for data analysis of the distribution of PMR movement activities along the time axis; differences between treatment and respective controls are expressed by an aggregated value integrating the time-resolved density of the movement parameter as a measure for a chemically elicited PMR effect. Logistic concentration-PMR effect relationships were modeled for neuroactive test compounds with different modes of action (acetylcholinesterase inhibition, activation and inhibition of voltage-gated sodium channels); 50% effect concentrations (EC50) were in the low to medium μM range (EC50 < 10 μM for flucythrinate, esfenvalerate, azinphos-methyl, propoxur; EC50 > 10 μM for tricaine). Modulation of movement activities in different phases of the PMR (i.e., “fingerprint”) by neuroactive test compounds varied across concentrations, showing that mode of action-specific PMR fingerprints are also concentration-dependent. Above concentrations causing 10% lethality (LC10; 48 h), 3,4-dichloroaniline caused movement inhibition. This substance presumably is not neuroactive; its effect on the PMR therefore is considered a secondary toxic effect. Quantitative morphological examinations of chemically exposed embryos showed that malformations occurred only above PMR effect concentrations, indicating that changes in the PMR were not due to such indirect effects. The PMR assay will provide a useful measure in ecotoxicological risk assessment of neuroactive chemicals with zebrafish embryos and could potentially be used to infer acute fish toxicity levels from PMR effect concentrations of neurotoxic compounds.
Topics: Acetylcholinesterase; Animal Testing Alternatives; Animals; Data Analysis; Embryo, Nonmammalian; Neurotoxicity Syndromes; Zebrafish
PubMed: 34363684
DOI: 10.14573/altex.2004021 -
International Journal of Molecular... Mar 2021Poisoning with organophosphorus compounds (OPCs) represents an ongoing threat to civilians and rescue personal. We have previously shown that oximes, when administered...
Poisoning with organophosphorus compounds (OPCs) represents an ongoing threat to civilians and rescue personal. We have previously shown that oximes, when administered prophylactically before exposure to the OPC paraoxon, are able to protect from its toxic effects. In the present study, we have assessed to what degree experimental (K-27; K-48; K-53; K-74; K-75) or established oximes (pralidoxime, obidoxime), when given as pretreatment at an equitoxic dosage of 25% of LD, are able to reduce mortality induced by the OPC azinphos-methyl. Their efficacy was compared with that of pyridostigmine, the only FDA-approved substance for such prophylaxis. Efficacy was quantified in rats by Cox analysis, calculating the relative risk of death (RR), with RR=1 for the reference group given only azinphos-methyl, but no prophylaxis. All tested compounds significantly ( ≤ 0.05) reduced azinphos-methyl-induced mortality. In addition, the efficacy of all tested experimental and established oximes except K-53 was significantly superior to the FDA-approved compound pyridostigmine. Best protection was observed for the oximes K-48 (RR = 0.20), K-27 (RR = 0.23), and obidoxime (RR = 0.21), which were significantly more efficacious than pralidoxime and pyridostigmine. The second-best group of prophylactic compounds consisted of K-74 (RR = 0.26), K-75 (RR = 0.35) and pralidoxime (RR = 0.37), which were significantly more efficacious than pyridostigmine. Pretreatment with K-53 (RR = 0.37) and pyridostigmine (RR = 0.52) was the least efficacious. Our present data, together with previous results on other OPCs, indicate that the experimental oximes K-27 and K-48 are very promising pretreatment compounds. When penetration into the brain is undesirable, obidoxime is the most efficacious prophylactic agent already approved for clinical use.
Topics: Animals; Azinphosmethyl; Cholinesterase Inhibitors; Inhibitory Concentration 50; Molecular Weight; Organophosphorus Compounds; Oximes; Pesticides; Proportional Hazards Models; Rats, Wistar; Risk; Survival Analysis; Rats
PubMed: 33802843
DOI: 10.3390/ijms22063072 -
Analytical Biochemistry May 2021Intentional or unintentional intake of anticholinesterase pesticides became common due to their extensive use in agricultural and domestic purposes, resulting in...
Intentional or unintentional intake of anticholinesterase pesticides became common due to their extensive use in agricultural and domestic purposes, resulting in numerous poisoning cases. A simple, accurate, and sensitive gas chromatography-ion trap mass spectrometry-based method for the quantification of 12 anticholinesterase pesticides (monocrotophos, dimethoate, dichlorvos, azinphos-methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, parathion, methidathion, and terbufos) in serum was developed, and its utility in patients with alleged pesticides poisoning was assessed. The quantification was performed using liquid-liquid extraction by toluene/chloroform (4:1,v/v) with 500 μL of serum. On column limit of detection and limit of quantification were less than 50.00 μg/L. The recovery ranged from 97.54 to 103.23%. The calibration curves were linear (R > 0.9937). Accuracy was found to be between - 7.1 and 7.2%. Intra-day and inter-day reproducibility was less than 17% for the spiked quality control serum samples. The level of pesticide in serum quantified by the validated method correlated with clinical signs and symptoms, pseudo-cholinesterase activity, total atropine dose, length of hospital stay, and clinical outcome in 15 patients with alleged pesticide poisoning. The validated method may be used for monitoring and prognosis in patients with pesticide poisoning and diagnosis of poisoning in forensic toxicology.
Topics: Calibration; Cholinesterase Inhibitors; Gas Chromatography-Mass Spectrometry; Humans; Liquid-Liquid Extraction; Pesticides; Reproducibility of Results; Spectrometry, Mass, Electrospray Ionization
PubMed: 33705722
DOI: 10.1016/j.ab.2021.114158 -
Chemosphere Dec 2020A new treatment method using a deep eutectic solvent embedded melamine sponge (DES-MS) was studied for the removal of organic pollutants from water and soil samples....
A new treatment method using a deep eutectic solvent embedded melamine sponge (DES-MS) was studied for the removal of organic pollutants from water and soil samples. Five organophosphorus pesticides (OPPs) consisting of azinphos-methyl (AZP), parathion-methyl (PRT), fenitrothion (FNT), diazinon (DIZ) and chlorpyrifos (CPF), and two dyes including acid blue 29 (AB29) and malachite green (MG) were used as the model pollutants. DESs were easily prepared from tetrabutylammonium bromide (TBABr) and various fatty acids. The synthesised DESs were loaded into the sponge before being utilized for the removal of the studied pollutants. After the removal, the residual OPPs or dyes in the supernatant was quantified by high performance liquid chromatography or derivative spectrophotometry, respectively. The proposed method was simple, rapid, environmentally friendly and effective with the removal efficiency higher than 70% for various samples. Moreover, the removal of various dyes was successfully achieved with the efficiency greater than 65% under the optimum condition.
Topics: Coloring Agents; Environmental Restoration and Remediation; Limit of Detection; Pesticides; Resins, Synthetic; Soil; Soil Pollutants; Solvents; Triazines; Wastewater; Water Pollutants, Chemical; Water Purification
PubMed: 32679376
DOI: 10.1016/j.chemosphere.2020.127590 -
Pesticide Biochemistry and Physiology Feb 2020The organophosphorus pesticides azinphos-methyl (AZM) and chlorpyrifos (CPF) exert their toxic action by inhibition of acetylcholinesterase, but non-target processes...
Differential effects of azinphos-methyl and chlorpyrifos on polyamine oxidative metabolism during the embryonic development of Rhinella arenarum and its relation to oxidative stress.
The organophosphorus pesticides azinphos-methyl (AZM) and chlorpyrifos (CPF) exert their toxic action by inhibition of acetylcholinesterase, but non-target processes such as polyamine metabolism can also be affected. Our objective was to evaluate the effects of different concentrations of AZM (0.5-, 2- and 9 mg L) and CPF (0.5- and 1 mg L) on polyamine oxidative metabolism along Rhinella arenarum embryonic development and to explore its relationship to oxidative stress. Free and conjugated polyamines were measured by HPLC. The activity of spermine oxidase (SMOX), N-acetylpolyamine oxidase (PAOX) and diamine oxidase (DAO) were measured through kinetic spectrofluorometry. Free putrescine and spermine were significantly increased in open mouth embryos exposed to AZM. Free polyamine levels were not affected by CPF exposure. In embryos exposed to AZM, DAO was increased in tail bud stage and SMOX was increased in open mouth stage, while embryos exposed to CPF showed an increase of PAOX activity in tail bud stage and a decrease of DAO and SMOX activity in open mouth stage. Polyamine levels and oxidative degradation enzymes respond differently if R. arenarum embryos are exposed to AZM or CPF, despite that both insecticides belong to the same chemical family. The early increase of DAO and PAOX would play a protective role to guarantee the normal progression of embryonic development. The increased production of reactive species might contribute to an oxidative stress situation generated by exposure to the insecticides and to the alteration of the antioxidant defense system. In tail bud stage embryos, PAOX and SMOX were positively correlated to acetylcholinesterase activity and reduced glutathione levels (GSH), and negatively correlated to the antioxidant enzymes catalase (CAT) and glutathione S-transferase (GST). In complete operculum embryos, a negative correlation between antioxidant parameters and polyamine levels and polyamine oxidative metabolism was observed, except for SMOX, which showed a low positive correlation with CAT and GSH and a negative correlation to PAOX and DAO. We suggest the use of DAO and PAOX as biomarkers of exposure to AZM and CPF, respectively, as they respond earlier than the classical biomarker acetylcholinesterase.
Topics: Azinphosmethyl; Chlorpyrifos; Embryonic Development; Oxidative Stress; Polyamines
PubMed: 31973851
DOI: 10.1016/j.pestbp.2019.10.007 -
RSC Advances Oct 2019A new bacterial genotoxicity detection strain was constructed, in which the cell lysis gene of from a lambda phage was controlled by a new designed SOS responsive...
A new bacterial genotoxicity detection strain was constructed, in which the cell lysis gene of from a lambda phage was controlled by a new designed SOS responsive element, designated as BL21/pUC-PST. The biosensor responded only after 0.5 h contact with mutagens and the changes in cell culture turbidity could be easily differentiated with the naked eyes from the control sample. This SOS/ system presented a dose-dependent manner to five model DNA-damaging agents with an improved detection sensitivity. The limits of detection (LODs) were 0.026 μM for mitomycin C, 320.4 μM for azinphos-methyl, 34.4 μM for methyl methanesulfonate, 4.6 μM for dithianone and 6.0 μM for dichlofluanid, which were much lower than previously reported. By performing binary and ternary mixture experiments, the toxic equivalency concept was validated in the SOS/ system by comparison with bioanalytical equivalent concentrations (BEQ) and overall toxic equivalent concentration (TEQ) using Cr(vi) as the reference compound. Pearson analysis indicated that a strong correlation existed between the TEQ and BEQ values. Thus the TEQ could be presented as the Cr(vi) equivalent concentration from its dose-effect lysis profiles for the environmental sample. The proposed genotoxicity reporter strain allows for easier qualitative characterization and quantitative interpretation of the TEQ values using Cr(vi) as the reference for environmental water samples.
PubMed: 35528065
DOI: 10.1039/c9ra06202e