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【Objective】The study aims to verify the application effect of bacterial agent PA9 degrading omethoate which residual in the soil. Soil physical and chemical properties, tomato growth and soil microbial diversity affect by bacterial agent PA9 were researched at the same time.【Method】Bacterial agent PA9 was made from bacteria strain ZZY-C13-1-9, when omethoate artificial add into the soil about 100 mg/kg, the bacterial agent PA9 were applied 0.1%. The period of remediation lasted for 50 days. Soil samples were taken every 10 days. The content of omethoate in soil were measured by HPLC. A selective culture medium is used to isolate strain ZZY-C13-1-9. The microbial diversity were measured by illumina miSeq high-throughput sequencing. Soil physical and chemical indexes were determined by national standard method. Tomato growth index were monitored.【Result】Initial content of omethoate in soil was 100 mg/kg at 0 days. After 40 days, the omethoate content in soil decrease to 5.3 mg/kg at remediation experimental group, which was significantly different with control group (48.79 mg/kg). Microbial strain ZZY-C13-1-9 could colonize in the soil and the proportion of soil microorganisms in omethoate soil increased after 10 - 20 days of remediation. The residual omethoate content in the soil was significantly reduced, which indicated that the functional strain could play a role in degrading omethoate in contaminated soil. The results of high-throughput sequencing showed that the proportion of Pseudomonas sp. in soil microbial flora decreased with the decrease of omethoate content, indicating that the bacterial agent PA9 would not permanently change the distribution of soil microbial diversity, and the restored soil could effectively restore the diversity of bacterial flora. The contents of total nitrogen, microbial nitrogen, available phosphorus and MWD in soil aggregates increased significantly compared with the control, and the use of microbial agent PA9 had no negative effect on the growth of tomato.【Conclusion】The bacterial agent PA9 can colonize and accelerate the degradation of omethoate in omethoate-contaminated soil in a short period of time, improve the microbial diversity of contaminated soil and have no adverse effects on the physical and chemical properties of the soil and the planting of tomatoes.

:【Objective】The study aims to verify the application effect of bacterial agent PA9 degrading omethoate which residual in the soil. Soil physical and chemical properties, tomato growth and soil microbial diversity affect by bacterial agent PA9 were researched at the same time. 【Method】Bacterial agent PA9 was made from bacteria strain ZZY-C13-1-9, when omethoate artificial add into the soil about 100 mg/kg, the bacterial agent PA9 were applied 0.1%. The period of remediation lasted for 50 days. Soil samples were taken every 10 days . The content of omethoate in soil were measured by HPLC. A selective culture medium is used to isolate strain ZZY-C13-1-9. The microbial diversity were measured by illumina miSeq high-throughput sequencing. Soil physical and chemical indexes were determined by national standard method. Tomato growth index were monitored. 【Result】Initial content of omethoate in soil was 100 mg/kg at 0 days. After 40 days, the omethoate content in soil decrease to 5.3 mg/kg at remediation experimental group, which was significantly different with control group (48.79 mg/kg) . Microbial strain ZZY-C13-1-9 could colonize in the soil and the proportion of soil microorganisms in omethoate soil increased after 10 - 20 days of remediation. The residual omethoate content in the soil was significantly reduced, which indicated that the functional strain could play a role in degrading omethoate in contaminated soil. The results of high-throughput sequencing showed that the proportion of Pseudomonas sp. in soil microbial flora decreased with the decrease of omethoate content, indicating that the bacterial agent PA9 would not permanently change the distribution of soil microbial diversity, and the restored soil could effectively restore the diversity of bacterial flora. The contents of total nitrogen, microbial nitrogen, available phosphorus and MWD in soil aggregates increased significantly compared with the control, and the use of microbial agent PA9 had no negative effect on the growth of tomato.【Conclusion】The bacterial agent PA9 can colonize and accelerate the degradation of omethoate in omethoate-contaminated soil in a short period of time, improve the microbial diversity of contaminated soil and have no adverse effects on the physical and chemical properties of the soil and the planting of tomatoes. [ABSTRACT FROM AUTHOR]

Through a field experiment, the dissipation pattern of dimethoate in grapes was evaluated during December 2020 - February 2021. Dimethoate 30%EC was sprayed twice at ten-days interval at recommended (X) dose (445 g a.i ha-1) and double the recommended (2x) dose (890 g a.i ha-1). The samples were collected from 0 (2hr), 1, 3, 5, 7, 10, 15 and 20 days or till degradation to below detectable level (BDL) and at harvest time. The residues were extracted by the modified QuEChERS method and analyzed by LCMS. The method performance was satisfactory in terms of SANTE guidelines and with good linearity (r²>0.99). The mean total dimethoate residue including omethoate was 1.047 and 2.168 mg kg-1 at x and 2x doses, respectively with half-lives of 5.47 and 5.59 days. The calculated Risk Quotient (RQ) at both x and 2x dose with Good Agricultural Practices (GAP) indicated that for dimethoate these are not safe for human health due to the intake of residue. [ABSTRACT FROM AUTHOR]

1. Dimethoate is an organophosphate insecticide that is converted in vivo to omethoate, the active toxic moiety. Omethoate inhibits acetylcholinesterase (AChE) in the brain and red blood cells (RBCs). This paper describes the development of rat and human physiologically-based pharmacokinetic/pharmacodynamic (PBPK/PD) models for dimethoate. 2. The model simulates the absorption and distribution of dimethoate and omethoate, the conversion of dimethoate to omethoate and to other metabolites, the metabolism and excretion of omethoate, and the inhibition of RBC and brain AChE. An extensive data collection program to estimate metabolism and inhibition parameters is described. 3. The suite of models includes an adult rat, post-natal rat, and human model. The rat models were evaluated by comparing model predictions of dimethoate and omethoate to measured blood time course data, and with RBC and brain AChE inhibition estimates from an extensive database of in vivo AChE measurements. 4. After the demonstration of adequately fitted rat models that were robust to sensitivity analysis, the human model was applied for estimation of points-of-departure (PODs) for risk assessment using the human-specific parameters in the human PBPK/PD model. Thus, the standard interspecies uncertainty factor can be reduced from 10X to 1X. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

1. Dimethoate is an organophosphate insecticide. The objective of this work was to determine the enzymatic kinetics of metabolism of dimethoate and its active metabolite omethoate in rats and humans and obtain key input parameters for physiologically based pharmacokinetic (PBPK) model. 2. First, the intrinsic clearance of dimethoate expressed as formation rate of omethoate was determined to be ∼42-fold lower in human liver microsomes (HLM) (0.39 µL/min/mg) than in rat liver microsomes (RLM) (16.6 µL/min/mg) by an LC/MS/MS method. Next, dimethoate clearance in liver microsomes was determined using parent depletion and total [14C]-metabolite formation methods. Results from both approaches showed slower clearance of dimethoate in HLM (1.1–3.3 µL/min/mg) than in RLM (12.7–17.4 µL/min/mg). 3. Investigation of in vitro enzymatic kinetics of omethoate demonstrated that the intrinsic clearance rates for omethoate in adult and juvenile RLM and HLM were similar. No significant turnover of dimethoate was apparent in rat cytosol or plasma. In contrast, degradation of omethoate in human plasma was slightly higher than in rat plasma. 4. Finally, toxicokinetics of dimethoate were determined in adult and juvenile rats. In both age groups, following oral dosing, absorption of dimethoate was rapid with formation of significant amounts of omethoate. [ABSTRACT FROM AUTHOR]

Resistance to pesticides is typically identified via laboratory bioassays after field control failures are observed, but the results of such assays are rarely validated through experiments under field conditions. Such validation is particularly important when only a low-to-moderate level of resistance is detected in the laboratory. Here we undertake such a validation for organophosphate resistance in the agricultural pest mite Halotydeus destructor, in which low-to-moderate levels of resistance to organophosphorus pesticides have evolved in Australia. Using data from laboratory bioassays, we show that resistance to the organophosphate chlorpyrifos is higher (around 100-fold) than resistance to another organophosphate, omethoate (around 7-fold). In field trials, both these chemicals were found to effectively control pesticide-susceptible populations of H. destructor. However, when applied to a resistant mite population in the field, the effectiveness of chlorpyrifos was substantially decreased. In contrast, omethoate remained effective when tested alone or as a mixture with chlorpyrifos. We also show that two novel (non-pesticide) treatments, molasses and wood vinegar, are ineffective in controlling H. destructor when sprayed to pasture fields at rates of 4 L/ha. These findings suggest a close link between levels of resistance quantified through laboratory bioassays and the field effectiveness of pesticides; however, in the case of H. destructor, this does not necessarily mean all field populations possessing organophosphate resistance will respond similarly given the potentially complex nature of the underlying resistance mechanism(s). [ABSTRACT FROM AUTHOR]

A simple homogeneous photoelectrochemical (PEC) sensing platform based on an alkaline phosphatase (ALP)–mediated pesticide assay was established for the sensitive detection of omethoate (OM). The Bi2S3@Bi2Sn2O7 heterojunction was used as a photoactive material to provide stable background photocurrent signals. The inhibition of OM on ALP and PEC determination was carried out in the homogeneous system. In the absence of OM, dephosphorylation of L-ascorbic acid 2-phosphate trisodium salt (AAP) was catalyzed by ALP to produce the enzyme-catalyzed product (L-ascorbic acid, AA). AA, as an electron donor, could capture photogenerated holes on the Bi2S3@Bi2Sn2O7 heterojunction, thus inhibiting the recombination of electron holes to achieve an increase of the photocurrent signal. When the OM was introduced, the enzyme activity of ALP was reduced due to the organophosphorus pesticides (OPs)–based enzyme inhibition, and the AA produced by catalytic hydrolysis was also reduced, thus reducing the photocurrent signal. Compared with the traditional PEC sensor for OPs, this homogeneous PEC sensor avoided immobilization procedures, covalent labeling, separation, and the steric hindrance effect caused by immobilized biomolecules, which achieved high recognition efficiency and caused a reduction in analysis time. Additionally, an ALP-mediated pesticide assay for the determination of OPs with a simplified experimental process further improved the stability and reproducibility of the PEC sensor. The PEC sensor showed high sensitivity to the target OM within a dynamic range of 0.05 ~ 500 ng mL−1, and the detection limit was 0.0146 ng mL−1. Additionally, the PEC biosensing system showed good selectivity and anti-interference ability, and exhibited a satisfactory result in spinach and mustard samples. A homogeneous PEC biosensor based on ALP inhibition strategy was constructed for OM detection in vegetable samples via Bi2S3@Bi2Sn2O7 heterojunction as the photoactive substrate material [ABSTRACT FROM AUTHOR]

A smartphone colorimetric sensor based on the Pt@Au nanozyme was successfully developed for the visual and quantitative detection of omethoate in fruit and vegetables. The anti-omethoate antibody was conjugated on the surface of the Pt@Au nanozyme as a catalytic functional signal probe, and coating antigen conjugated on the surface of magnetic polystyrene microspheres (MPMs) was used as a separation capture probe. In the sensing system, when the catalytic functional signal probe was combined with a separation capture probe containing no omethoate, the visible blue color appeared with the addition of tetramethylbenzidine (TMB) chromogenic solution, and the maximum B value of the sensing system was obtained via the smartphone. With increasing concentrations of omethoate, the visualization of the sensing system decreased, and the B-value obtained via the smartphone dropped. Under optimal detection conditions, the omethoate could be detected in a linear range of 0.5–50 μg/L (R2 = 0.9965), with a detection limit of 0.01 μg/L. The accuracy and reliability of the detection results of this colorimetric sensor were successfully confirmed by enzyme linked immunosorbent assay (ELISA) and gas chromatography. This colorimetric sensor provides a technical reference and potential strategy for the immunoassay of hazard factors in resource-scarce laboratories. [ABSTRACT FROM AUTHOR]

Organophosphate pesticides are used in large quantities. Once accumulated in the environment, they exhibit toxic effects on non-target organisms. Dimethoate, a frequently used insecticide, and its oxo-analog omethoate inhibit acetylcholinesterase and are toxic for mammals. However, under environmental conditions, they also undergo chemical transformations and decomposition. Nevertheless, the systematic data about dimethoate and omethoate decomposition are missing. We performed a systematic analysis of dimethoate and omethoate decomposition under different pH conditions and estimated their long-term eco-neurotoxic effects. Dimethoate and omethoate decompose rapidly in alkaline aqueous solutions (half-lives 5.7 ± 1.4 and 0.89 ± 0.21 days) but are highly stable in acidic solutions (half-lives 124 ± 18 and 104 ± 9 days). These differences are explained using quantum chemical calculations, indicating that a weaker P–S bond in omethoate is more susceptible to hydrolysis, particularly at a high pH. The toxicity of these pesticide solutions decreases over time, indicating that no or very little of highly more toxic omethoate is formed during hydrolysis of dimethoate, pointing to the advantage of alkaline hydrolysis over other techniques for dimethoate removal. Presented data are used to benchmark dimethoate and omethoate concentrations and toxicity in contaminated water in the pH range 3 to 9 for up to 70 days upon the release in the environment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Contamination with pesticides has inflicted substantial harm on human health; therefore, developing rapid, ultra-sensitive, and non-labelling simultaneous detection methods for multiple pesticides is necessary. In this study, we demonstrated that α-hemolysin (α-HL) nanopore sensor can detect and discriminate organophosphorus pesticides of phoxim and omethoate in a single nanopore without requiring labels of the probes or purification of the pesticides in real samples. Aptamers specifically recognise and bind pesticides to obtain pesticide-aptamer complexes that produce characteristic current signals while passing through the nanopore. Phoxim and omethoate were accurately distinguished by a portable instrument within minutes, and their detection sensitivity was up to the femtomole level, whether detected alone or simultaneously. The detection limits of phoxim and omethoate were 8.13 × 10−16 M and 4.16 × 10−15 M. The recoveries of phoxim and omethoate from pear, tomato, and cucumber samples were 82.0–107.0 % and 81.9–118.3 % respectively, with coefficient of variable below 8.0 %. • The α-hemolysin nanopore sensor can detect and discriminate phoxim and omethoate in real samples. • The sensor enables simultaneously detection of phoxim and omethoate within minutes. • The detection limit of the sensor is up to the femtomole level. • The sensor is as reliable and accurate as UHPLC-MS/MS. [ABSTRACT FROM AUTHOR]

This study presents the method development, validation, and simultaneous determination of dimethoate and its metabolite omethoate in curry leaf. Samples were extracted following modified quick, easy, cheap, effective, rugged, and safe extraction protocol and analyzed using liquid chromatography‐tandem mass spectrometry. The limit of quantification in the matrix was 0.005 μg g−1 for dimethoate and omethoate. Extraction using acetonitrile recorded the average recoveries in the range of 82.25 to 112.97% for dimethoate and 85.57 to 107.22% for omethoate at 0.005, 0.025 and 0.050 μg g−1 fortification levels and relative standard deviation less than 5%. Similarly, the relative standard deviation values for intraday (Repeatability) and interday (Reproducibility) tests were less than 15%. Dissipation kinetics of dimethoate 30% emulsifiable concentrate at 200 and 400 g a.i h−1 recorded initial deposits of 5.20 and 10.05 μg g−1 and 0.33 and 0.48 μg g−1 for dimethoate and omethoate, respectively, and half‐life of 3.07 and 3.34 days. The estimated hazard index value found more than one at a day after dimethoate application. It is not safe for consumer health to use curry leaves in the initial days after application. [ABSTRACT FROM AUTHOR]

To explore the association between polymorphisms in microRNAs (miRNAs) and the cholinesterase (ChE) activity in omethoate-exposed workers, we recruited 180 omethoate-exposed workers and 115 controls to measure their ChE activity using acetylcholine and dithio-bis-(nitrobenzoic acid) and genotype susceptible SNPs in their miRNA by time-of-flight mass spectrometry. ChE activity in the exposure group was lower than that in the control group (P < 0.001). The analysis of covariance result showed that ChE activity was lower in the (- -/- T) genotype in miR-30a rs111456995 (1.97 ± 0.47) than in the TT genotype (2.23 ± 0.59) of the exposure group (P = 0.004). Multivariate linear regression was performed to find influencing factors on ChE activity, and variables kept in the model included omethoate exposure (b = −1.094, P < 0.001), gender (b = −0.381, P < 0.001), miR-30a rs111456995 (- -/- T)(b = −0.248, P < 0.001), and drinking (b = 0.258, P =0.019). The results suggest that individuals carrying a (- -/- T) genotype in miR-30a rs111456995 were more susceptible to damage in their cholinesterase induced by omethoate exposure. [ABSTRACT FROM AUTHOR]

BACKGROUND Commercially formulated pesticide products are complex mixtures of one or more active ingredients and several co‐ingredients. However, the modifying effect of co‐ingredients on skin uptake and glove barrier protection has been poorly studied. The aim of this study was to understand the role of formulation co‐ingredients in skin and glove barrier protection performance against organophosphate insecticides. RESULTS: We adapted standard in vitro diffusion cell methods to test permeation kinetics of two commonly used organophosphate insecticides: dimethoate and omethoate. For spray dilutions, dimethoate and omethoate did not reach breakthrough glove permeation rate (1 μg·cm−2·min−1) and no or little skin permeation was observed for up to 8 h, regardless of formulation. For exposure conditions involving highly concentrated products, significant differences in glove permeation were observed between different formulations of dimethoate (about 1.5‐fold, P < 0.05) and of omethoate (184‐fold, P < 0.001). In contrast, no difference (P > 0.05) was observed between formulations in terms of skin permeation. CONCLUSION: These results suggest that co‐ingredients play a critical role in glove barrier protection against undiluted organophosphate insecticides, whereas their influence on skin uptake was insignificant within the exposure time tested. This implies that dermal exposure risk may vary between handling different formulated products of the same active ingredient hence recommending a common glove material for different formulations of the same chemical without careful consideration of co‐ingredients and their permeation properties may not necessarily be appropriate. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Ingestion of agricultural organophosphorus insecticides is a significant cause of death in rural Asia. Patients often show acute respiratory failure and/or delayed, unexplained signs of neuromuscular paralysis, sometimes diagnosed as "Intermediate Syndrome". We tested the hypothesis that omethoate and cyclohexanol, circulating metabolites of one agricultural formulation, cause muscle weakness and paralysis. Acetylcholinesterase activity of insecticide components and metabolites was measured using purified enzyme from eel electroplaque or muscle homogenates. Mechanomyographic recording of pelvic limb responses to nerve stimulation was made in anaesthetized pigs and isometric force was recorded from isolated nerve-muscle preparations from mice. Omethoate and cyclohexanol were administered intravenously or added to physiological saline bathing isolated muscle. We also assessed the effect of MgSO4 and cooling on neuromuscular function. Omethoate caused tetanic fade in pig muscles and long-lasting contractions of the motor innervation zone in mouse muscle. Both effects were mitigated, either by i.v. administration of MgSO4in vivo or by adding 5 mM Mg2+ to the medium bathing isolated preparations. Combination of omethoate and cyclohexanol initially potentiated muscle contractions but then rapidly blocked them. Cyclohexanol alone caused fade and block of muscle contractions in pigs and in isolated preparations. Similar effects were observed ex vivo with cyclohexanone and xylene. Cyclohexanol-induced neuromuscular block was temperature-sensitive and rapidly reversible. The data indicate a crucial role for organophosphorus and solvent metabolites in muscle weakness following ingestion of agricultural OP insecticide formulations. The metabolites omethoate and cyclohexanol acted conjointly to impair neuromuscular function but their effects were mitigated by elevating extracellular Mg2+ and decreasing core temperature, respectively. Clinical studies of MgSO4 therapy and targeted temperature management in insecticide-poisoned patients are required to determine whether they may be effective adjuncts to treatment. [ABSTRACT FROM AUTHOR]

Dimethoate ([O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate]) is an organophosphate insecticide and acaricide widely used for agricultural purposes. Genotoxicity refers to the ability of a chemical agent interact directly to DNA or act indirectly leading to DNA damage by affecting spindle apparatus or enzymes involved in DNA replication, thereby causing mutations. Taking into consideration the importance of genotoxicity induced by dimethoate, the purpose of this manuscript was to provide a mini review regarding genotoxicity induced by dimethoate as a result of oxidative stress. The present study was conducted on studies available in MEDLINE, PUBMED, EMBASE, and Google scholar for all kind of articles (all publications published until May, 2020) using the following key words: dimethoate, omethoate, DNA damage, genetic damage, oxidative stress, genotoxicity, mutation, and mutagenicity. The results showed that many studies were published in the scientific literature; the approach was clearly demonstrated in multiple tissues and organs, but few papers were designed in humans. In summary, new studies within the field are important for better understanding the pathobiological events of genotoxicity on human cells, particularly to explain what cells and/or tissues are more sensitive to genotoxic insult induced by dimethoate. [ABSTRACT FROM AUTHOR]

Omethoate is an acute organophosphorus pesticide which is widely used. It presents a high pollution potential and health risk nowadays. In this study, Bacillus sp. YB-10, which was isolated from the activated sludge of a pharmaceutical wastewater treatment plant, was used for degrading omethoate. The culture conditions and degradation characteristics were investigated. Results showed that the Bacillus sp. YB-10 could degrade omethoate through co-metabolism. The optimal carbon and nitrogen sources were glucose and NH4NO3, respectively. Response surface methodology (RSM) results showed that the most appropriate nutrition ratio of C:N:P was 3:1:1 when degrading 1,000 mg/L of omethoate. Omethoate degradation kinetics could be described by a first-order rate equation. The optimal degradation conditions were pH of 7.0, temperature of 30°C, initial bacteria concentration of 0.25%, rotation speed of 150 r/min. Under the optimal conditions, the degradation rate reached 77.24% within 5 d by the Bacillus sp. YB-10 when the initial omethoate concentration was 1,000 mg/L. [ABSTRACT FROM AUTHOR]

A smartphone colorimetric sensor based on the Pt@Au nanozyme was successfully developed for the visual and quantitative detection of omethoate in fruit and vegetables. The anti-omethoate antibody was conjugated on the surface of the Pt@Au nanozyme as a catalytic functional signal probe, and coating antigen conjugated on the surface of magnetic polystyrene microspheres (MPMs) was used as a separation capture probe. In the sensing system, when the catalytic functional signal probe was combined with a separation capture probe containing no omethoate, the visible blue color appeared with the addition of tetramethylbenzidine (TMB) chromogenic solution, and the maximum B value of the sensing system was obtained via the smartphone. With increasing concentrations of omethoate, the visualization of the sensing system decreased, and the B-value obtained via the smartphone dropped. Under optimal detection conditions, the omethoate could be detected in a linear range of 0.5–50 μg/L (R2 = 0.9965), with a detection limit of 0.01 μg/L. The accuracy and reliability of the detection results of this colorimetric sensor were successfully confirmed by enzyme linked immunosorbent assay (ELISA) and gas chromatography. This colorimetric sensor provides a technical reference and potential strategy for the immunoassay of hazard factors in resource-scarce laboratories.

To investigate the fractioning of chlorpyrifos, omethoate, cypermethrin, and deltamethrin during wheat milling and the fate of four pesticides during Chinese steamed bread (CSB) processing, wheat samples, which were sprayed twice with chlorpyrifos, omethoate, cypermethrin, and deltamethrin at three levels of concentrations during the grain‐filling stage, were milled, and wheat flour was processed to CSB. The residues of four pesticides in the milling products, kneaded dough, fermented dough, and CSB were determined with GC‐MS/MS. The concentrations of chlorpyrifos, omethoate, cypermethrin, and deltamethrin in bran were 1.46–1.57, 1.85–2.13, 1.27–1.86, and 1.63–2.33 times higher than those in wheat, respectively, while the residues of the four pesticides in shorts decreased approximately 27.97% to 57.02% for chlorpyrifos, 6.22% to 44.77% for cypermethrin, and 13.13% to 61.15% for deltamethrin compared with the residues in wheat (p <.05); however, omethoate levels approximately doubled in the ten‐fold treatment group in shorts compared with those in wheat (p <.05). The residues of the four pesticides in flour were significantly lower than those in wheat, ranging from 38.68% to 98.04%. Chlorpyrifos and omethoate levels showed a slight decrease during the kneading and fermentation process, and further decreases of 2.46%–29.51% for chlorpyrifos and 14.22%–71.11% for omethoate were found in CSB; however, most of the groups of cypermethrin and deltamethrin showed various degrees of increases in kneaded and fermented dough and steamed bread compared with flour. The mechanism of this increase is unknown and needs further research. [ABSTRACT FROM AUTHOR]

The aim of this study was to explore the association between metabolizing enzyme gene polymorphisms and the decrease in cholinesterase activity induced by omethoate exposure. A total of 180 workers exposed to omethoate over an extended period were recruited along with 115 healthy controls. Cholinesterase activity in whole blood, erythrocyte, and plasma was detected using acetylthiocholine and the dithio-bis-(nitrobenzoic acid) method. Six polymorphic loci of GSTT1(+/-), GSTM1(+/-), GSTP1 rs1695, CYP2E1 rs6413432, CYP2E1 rs3813867, and PON2 rs12026 were detected by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The gene-environment interactions were analyzed using the generalized linear model method. The cholinesterase activity of erythrocyte and plasma in the exposure group was significantly lower than that in the control group (P < 0.001) in general. The plasma cholinesterase activity in the TT + AT genotype in CYP2E1 rs6413432 was lower than that in the AA genotype in the exposure group (P = 0.016). Interaction between the AA genotype in CYP2E1 rs6413432 and omethoate exposure had a significant effect on plasma cholinesterase activity (P = 0.079). The decrease in plasma cholinesterase activity was associated with interaction between the AA genotypes in rs6413432 and omethoate exposure. [ABSTRACT FROM AUTHOR]

This study aimed to explore the residual dynamics and dietary risk of dimethoate and its metabolite omethoate in celery. Celery was sprayed with 40% dimethoate emulsifiable concentrate (EC) at either a low concentration of 600 g a.i./ha or a high concentration of 900 g a.i./ha. Plants in the seedling, transplanting, or middle growth stages were sprayed once, and the samples were collected 90 days after transplantation. Plants in the harvesting stage were sprayed two or three times. The samples were collected on days 3, 5, 7, 10, 14 and 21 after the last pesticide application. The dimethoate and omethoate compounds were extracted from the celery samples using acetonitrile, and their concentrations were detected using ultra-performance liquid chromatography-tandem mass spectrometry. Also, the dietary risk assessments of dimethoate and omethoate were conducted in various populations and on different foods in China. The metabolism led to the formation of omethoate from dimethoate in the celery. The degradation dynamics of dimethoate and total residues in greenhouse celery followed the first-order kinetic equation. The half-lives of the compounds were 2.42 days and 2.92 days, respectively. The celery which received one application during the harvesting stage had a final residue of dimethoate after 14 days, which was lower than the maximum residue limit (MRL) 0.5 mg kg−1 for Chinese celery. The final deposition of the metabolite omethoate after 28 days was less than the maximum residue limit of 0.02 mg kg−1 for Chinese celery. Furthermore, the risk quotients of dimethoate in celery were less than 1; therefore, the level of chronic risk was acceptable after day 21. Only children aged 2–7 years had an HQ of dimethoate more than 1 (an unacceptable level of acute risk), while the acute dietary risks to other populations were within acceptable levels. It was recommended that any dimethoate applications to celery in greenhouses should happen before the celery reached the harvesting stage, with a safety interval of 28 days.

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Telomere length was found to be associated with omethoate exposure and polymorphisms in certain genes among occupational workers. However, whether the polymorphisms in telomere-binding protein genes influence telomere length remains unclear. To explore the correlation between telomere length and polymorphisms in telomere-binding protein genes, telomere length in peripheral blood leukocytes was determined by real-time quantitative polymerase chain reaction in 180 omethoate-exposed workers and 115 healthy controls. Polymorphisms in 10 pairs of alleles were detected using flight mass spectrometry or polymerase chain reaction–restriction fragment length polymorphism technique. The results showed that individuals with GG genotype in TRF1 rs3863242 had longer telomere lengths than those with AG + AA genotype in the control group (p = 0.005). The multiple regression analysis suggested that both omethoate exposure (b = 0.526, p < 0.001) and TRF1 rs3863242 GG (b = 0.220, p = 0.002) were related to a longer telomere length. In conclusion, GG genotype in TRF1 rs3863242 is linked to prolongation of telomere length, and individuals with GG genotype are recommended to strengthen health protection in a Chinese occupational omethoate-exposed population. [ABSTRACT FROM AUTHOR]

Omethoate is an organophosphorus pesticide that poses a major health hazard, especially DNA damage. The purpose of this study was to investigate the factors affecting telomere length in workers exposed to omethoate by analyzing the interaction between cell cycle gene polymorphism and environmental factors. The exposure group consisted of 118 workers exposed to omethoate for 8–10 years, the control group comprised 115 healthy people without occupational toxicant exposure history. The telomere length of genomic DNA from peripheral blood leucocyte was determined with real-time PCR. Polymerase chain reaction and restriction fragment length polymorphism was used to detect the polymorphisms in p53, p21 and MDM2 gene. The telomere length in the (CA + AA) genotypes for p21 rs1801270 polymorphism was longer than that in the CC genotype in control group (P = 0.015). The generalized linear model analysis indicated the interaction of the p21 rs1801270 polymorphic (CA + AA) genotypes and smoking has a significant effect on telomere length (β = −0.258, P = 0.085). The prolongation of telomere length in omethoate-exposed workers was associated with genotypes (CA + AA) of p21 rs1801270, and interactions of (CA + AA) genotypes and smoking factor. [ABSTRACT FROM AUTHOR]

Intensive use of pesticides requires innovative approaches for their removal from the environment. Here we report the method for degradation of dimethoate in water using non-thermal plasma needle and analyze kinetics of dimethoate removal and possible degradation pathways. The effects of dimethoate initial concentration, plasma treatment time, Argon flow rate and the presence of radical promoters on the effectiveness of proposed method are evaluated. With argon flow rate of 0.5 slm (standard litres per minute) 1 × 10−4 M dimethoate can be removed within 30 min of treatment. Using UPLC analysis it was confirmed that one of the decomposition products is dimethoate oxo-analogue omethoate, which is in fact more toxic than dimethoate. However, the overall toxicity of contaminated water was reduced upon the treatment. The addition of H 2 O 2 as a free radical promoter enhances dimethoate removal, while K 2 S 2 O 8 results with selective conversion to omethoate. Using mass spectrometry in combination with the theoretical calculations, possible degradation pathways were proposed. The feasibility of the proposed method for dimethoate degradation in real water samples is confirmed. The proposed method is demonstrated as a highly effective approach for dimethoate removal without significant accumulation of undesirable toxic products and secondary waste. Image 1 • Development of an efficient treatment to remove water pollutants is urgent. • Non-thermal plasma needle is a new method for degradation of dimethoate in water. • This method enabled us to successfully remediate 1 × 10−4 M dimethoate from water. • The feasibility of the proposed method in real water samples is confirmed. [ABSTRACT FROM AUTHOR]

Abstract Omethoate, an organophosphorous pesticide, causes a variety of health effects, especially the damage of chromosome DNA. The aim of the study was to assess the correlation between polymorphisms of encoding miRNA genes and telomere length in omethoate–exposure workers. 180 workers with more than 8 years omethoate–exposure and 115 healthy controls were recruited in the study. Genotyping for the selected single nucleotide polymorphisms loci were performed using the flight mass spectrometry. Real-time fluorescent quantitative polymerase chain reaction(PCR) method was applied to determine the relative telomere length(RTL) in human peripheral blood leukocytes DNA. After adjusting the covariate of affecting RTL, covariance analysis showed that the female was significantly longer than that of the male in control group(P < 0.046). For the miR-145 rs353291 locus, this study showed that RTL of mutation homozygous AG+GG individuals was longer than that of wild homozygous AA in the exposure group (P = 0.039). In the control group, RTL with wild homozygous TT genotype in miR-30a rs2222722 polymorphism locus was longer than that of the mutation homozygous CC genotype (P = 0.038). After multiple linear regression analysis, the independent variables of entering into the model were omethoate–exposure (b = 0.562, P < 0.001), miR-145 rs353291 (AG+GG) (b = 0.205, P = 0.010). The prolongation of relative telomere length in omethoate exposed workers was associated with AG+GG genotypes in rs353291 polymorphism of encoding miR-145 gene. Graphical abstract fx1 Highlights • The encoding miRNA genes and telomere length under omethoate exposure. • Omethoate-exposure and miR-145 genetic polymorphism affect telomere length. • Prolongation of RTL in workers exposed to omethoate with rs353291 AG+GG genotypes. [ABSTRACT FROM AUTHOR]

Objective To study the decomposition kinetics of omethoate in blood. Methods The acetonitrile precipitated protein was added into the blood, with the chromatographic column of a Waters BEH C18 column （2.1 mm×50 mm, 1.7 μm）, the mobile phase of 5 mmol/L ammonium acetate aqueous solution-methanol, and the gradient elution with a flow rate of 0.3 mL/min and injection volume of 2 μL. With electrospray ionization （ESI） source and positive ion detection, qualitative and quantitative analyses were taken using multi-reaction monitoring mode. Omethoate standard was added into blank human blood to the mass concentrations of 0.78, 1.40, 2.30, 4.50, and 7.20 μg/mL, and each mass concentration was preserved at 3 temperatures of -20 ℃, 4 ℃, and 20 ℃, respectively. The content of omethoate was detected at different time points （0, 1, 3, 4, 7, 11, 15, 24, 32, 40, 48, 64, 80, 96, and 120 d）. Results Different concentrations of omethoate all showed a descended trend in human blood under different temperature conditions. The decomposition in storage environment of -20 ℃, 4 ℃, and 20 ℃ was fit to a one-compartment open model with a first-order kinetic process, which could be expressed as Ct=Coe-αt, with the calculated theoretical values of omethoate concentration close to the measured values. Conclusion All concentrations of omethoate are decomposed in the blood, which vary a lot in different preservation conditions. It is suggested that blood samples should be frozen and detected timely in suspected omethoate poisoning cases.

This work performed a large scale assessment for organophosphorus pesticides (OPPs) degradation activity of 121 Lactobacillus (L.) plantarum strains. Six L. plantarum strains (P9, IMAU80110, IMAU40100, IMAU10585, IMAU10209, and IMAU80070) were found to possess high capacity of degrading three commonly used OPPs, namely dimethoate, phorate, and omethoate; and they were selected for more detailed characterization. Moreover, the three OPPs were mainly detected in the culture supernatants but not in the cell extracts, further confirming that the OPPs were degraded rather than absorbed by the cells. Among the six selected strains, P9 was most tolerant to gastrointestinal juices and bile. We thus used ultra-high performance liquid chromatography electron spray ionization coupled with time-of-flight mass spectrometry (UPLC/ESI-Q-TOF/MS) to generate the metabolomic profiles of the strain P9 growing in MRS medium with and without containing phorate. By using orthogonal partial least squares discriminant analysis, we identified some potential phorate-derived degradative products. This work has identified novel lactic acid bacteria resources for application in pesticide degradation. Our results also shed light on the phorate degradation mechanism by L. plantarum P9.

Cholinesterase activity (ChA), the effective biomarker for organophosphate pesticide exposure, is possibly affected by single nucleotide polymorphisms (SNPs) in cell-cycle-related genes. One hundred and eighty workers with long-term exposure to omethoate and 115 healthy controls were recruited to explore the gene–gene and gene–environment interactions. The acetylthiocholine and dithio-bis-(nitrobenzoic acid) method was used to detect the cholinesterase activities in whole blood, erythrocytes and plasma. Genetic polymorphisms were determined by the PCR-RFLP and direct PCR electrophoresis methods. Statistical results showed that the cholinesterase activities of whole blood, erythrocytes and plasma in the exposure group were significantly lower than those in the control group (p

In order to explore the response dynamics of the activities of defense related enzymes in cotton leaves towards the interactive stress of Helicoverpa armigera herbivory and omethoate application, the activities of phenylalanine ammonia-lyase (PAL), lipoxygenase (LOX), and polyphenol oxidase (PPO) were examined from 6 to 126 h after cotton leaves were treated 12 h of H. armigera herbivory, and then sprayed with 800 mg L−1 omethoate. The results showed that the changes in the activities of PAL, LOX and PPO that occured under the interactive stress of H. armigera herbivory and omethoate application reflected the interactive effects of the two stresses on cotton defense. The similarity between the response dynamics of PAL, LOX, and PPO activities in cotton leaves under the interactive stress and that under H. armigera herbivory treatment alone showed that the induction of H. armigera herbivory on the activities of PAL, LOX and PPO in cotton leaves played a leading role in the interactive effects, and the effect of omethoate application played only a minor role. A joint factor analysis was performed according to a method which has been used to analyze the joint toxicity of pesticides; this analysis sought to clarify if there was a synergistic, antagonistic, or additive effect on PAL, LOX, and PPO activity in cotton leaves resulting from the interactive H. armigera herbivory and omethoate treatment. In the interactive effect on the response of PAL activity in cotton leaves, antagonistic effects of the omethoate application towards H. armigera herbivory were observed at 6 and 12 h. Synergistic effects were then observed at 18 and 30 h. Antagonistic effects were observed from 54 to 78 h and synergistic effects were finally observed at 126 h. The correlation between H. armigera herbivory and omethoate application in the interactive effect on cotton defense responses of LOX activity also fluctuated from synergism to antagonism during the time course. In the interactive effect on PPO activity, only antagonism was observed between H. armigera herbivory and omethoate application. In the interactive stress of H. armigera herbivory and omethoate application on cotton defense responses, omethoate affected the defense responses of cotton to H. armigera herbivory by producing antagonistic and synergistic effects. These results will be useful to understand the relationship between host plant and herbivorous pest.

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Omethoate, an organophosphorous pesticide, can cause a variety of health effects, especially the decrease of cholinesterase activity. The aim of this study is to explore the association of genetic polymorphisms of telomere binding proteins with cholinesterase activity in omethoate-exposed population. Cholinesterase activities in whole blood, red blood cell and plasma were detected using acetylthiocholine and dithio-bis-(nitrobenzoic acid) method; Genetic Genotyping of POT 1 rs1034794, POT 1 rs10250202, TERF 1 rs3863242 and TERT rs2736098 were performed with PCR-RFLP. The cholinesterase activities of whole blood, red blood cells and plasma in exposure group are significantly lower than that of the control group ( P  < 0.001). Multivariate analysis indicates that exposure group ( b  = − 1.016, P  < 0.001), agender ( b  = 0.365, P  < 0.001), drinking ( b  = 0.271, P  = 0.004) and TERF1 rs3863242 ( b  = − 0.368, P  = 0.016) had an impact on cholinesterase activities. The results suggest that individual carrying AG+GG genotypes in TERF 1 gene rs3863242 polymorphism were susceptible to damage in cholinesterase induced by omethoate. [ABSTRACT FROM AUTHOR]

This work performed a large scale assessment for organophosphorus pesticides (OPPs) degradation activity of 121 Lactobacillus (L.) plantarum strains. Six L. plantarum strains (P9, IMAU80110, IMAU40100, IMAU10585, IMAU10209, and IMAU80070) were found to possess high capacity of degrading three commonly used OPPs, namely dimethoate, phorate, and omethoate; and they were selected for more detailed characterization. Moreover, the three OPPs were mainly detected in the culture supernatants but not in the cell extracts, further confirming that the OPPs were degraded rather than absorbed by the cells. Among the six selected strains, P9 was most tolerant to gastrointestinal juices and bile. We thus used ultra-high performance liquid chromatography electron spray ionization coupled with time-of-flight mass spectrometry (UPLC/ESI-Q-TOF/MS) to generate the metabolomic profiles of the strain P9 growing in MRS medium with and without containing phorate. By using orthogonal partial least squares discriminant analysis, we identified some potential phorate-derived degradative products. This work has identified novel lactic acid bacteria resources for application in pesticide degradation. Our results also shed light on the phorate degradation mechanism by L. plantarum P9. [ABSTRACT FROM AUTHOR]

In this work, surface-enhanced Raman spectroscopy (SERS) was used with silver colloid substrate for rapid detection of omethoate (an organophosphate pesticide) in standard solution and peach extract. The findings demonstrated that the characteristic wavenumber of the pesticide could be precisely identified using the SERS method. The calibration curve was plotted between concentrations and Raman intensities of the target peak at 1649 cm−1 for the peach extract and at 1647 cm−1 for the standard solution. The coefficients of determination (R2) of 0.9829 and 0.98 were obtained for standard solution and for peach extract, respectively. The calculated limits of detection for omethoate in standard solution and in peach extracts were 0.001 mg L−1 and 0.01 mg kg−1, respectively. This study revealed that the proposed method could be used for the analysis of trace contaminants like omethoate in multifaceted food matrices. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: The dissipation behavior, pre‐harvest interval and dietary risk of carbosulfan, dimethoate, and their relevant metabolites were investigated in greenhouse cucumber in Tianjin, northern China, to ensure raw consumption safety. RESULTS: Carbosulfan was metabolized to carbofuran, dibutylamine, 3‐hydroxycarbofuran and 3‐ketocarbofuran, and dimethoate was degraded to omethoate in cucumber fruits and leaves. The dissipation of carbosulfan, carbofuran, 3‐hydroxycarbofuran and dimethoate fitted first‐order kinetics well, with R2 ranging from 0.912 to 0.992, and their half‐lives were 2.6, 2.7, 2.4 and 5.2 days in cucumber fruits and 2.8, 3.0, 4.6 and 2.5 days in leaves, respectively. The estimated daily intakes of the active ingredients and their relevant metabolites were 0.1–4% of the corresponding acceptable daily intakes. Acute oral exposure to carbofuran (a metabolite of carbosulfan) represented 367% of the acute reference dose (ARfD) for 1–6‐year‐old Chinese children and 227% for the general Chinese population. CONCLUSION: A minimum pre‐harvest interval of 12 days for carbosulfan is proposed to ensure safe consumption of cucumber. The slow dissipation rate of omethoate in cucumber reveals that a longer pre‐harvest interval (≥ 27 days) is necessary to prevent dietary risk when dimethoate is applied to cucumber. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this study, a hyperspectral imaging system of 866.4−1701.0 nm was selected and combined with multivariate methods to identify wheat kernels with different concentrations of omethoate on the surface. In order to obtain the optimal model combination, three preprocessing methods (standard normal variate (SNV), Savitzky−Golay first derivative (SG1), and multivariate scatter correction (MSC)), three feature extraction algorithms (successive projections algorithm (SPA), random frog (RF), and neighborhood component analysis (NCA)), and three classifier models (decision tree (DT), k-nearest neighbor (KNN), and support vector machine (SVM)) were applied to make a comparison. Firstly, based on the full wavelengths modeling analysis, it was found that the spectral data after MSC processing performed best in the three classifier models. Secondly, three feature extraction algorithms were used to extract the feature wavelength of MSC processed data and based on feature wavelengths modeling analysis. As a result, the MSC−NCA−SVM model performed best and was selected as the best model. Finally, in order to verify the reliability of the selected model, the hyperspectral image was substituted into the MSC−NCA−SVM model and the object-wise method was used to visualize the image classification. The overall classification accuracy of the four types of wheat kernels reached 98.75%, which indicates that the selected model is reliable.