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PloS One 2014Pesticide resistance monitoring is a crucial part to achieving sustainable integrated pest management (IPM) in agricultural production systems. Monitoring of resistance...
BACKGROUND
Pesticide resistance monitoring is a crucial part to achieving sustainable integrated pest management (IPM) in agricultural production systems. Monitoring of resistance in arthropod populations is initially performed by bioassay, a method that detects a phenotypic response to pesticides. Molecular diagnostic assays, offering speed and cost improvements, can be developed when the causative mutation for resistance has been identified. However, improvements to throughput are limited as genotyping methods cannot be accurately applied to pooled DNA. Quantifying an allele frequency from pooled DNA would allow faster and cheaper monitoring of pesticide resistance.
METHODOLOGY/PRINCIPAL FINDINGS
We demonstrate a new method to quantify a resistance allele frequency (RAF) from pooled insects via TaqMan assay by using raw fluorescence data to calculate the transformed fluorescence ratio k' at the inflexion point based on a four parameter sigmoid curve. Our results show that k' is reproducible and highly correlated with RAF (r >0.99). We also demonstrate that k' has a non-linear relationship with RAF and that five standard points are sufficient to build a prediction model. Additionally, we identified a non-linear relationship between runs for k', allowing the combination of samples across multiple runs in a single analysis.
CONCLUSIONS/SIGNIFICANCE
The transformed fluorescence ratio (k') method can be used to monitor pesticide resistance in IPM and to accurately quantify allele frequency from pooled samples. We have determined that five standards (0.0, 0.2, 0.5, 0.8, and 1.0) are sufficient for accurate prediction and are statistically-equivalent to the 13 standard points used experimentally.
Topics: Animals; Aphids; Australia; Carbamates; Fluorescence; Gene Frequency; Genotyping Techniques; Gossypium; Insecticide Resistance; Plasmids; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Polymorphism, Single Nucleotide; Pyrimidines; Reference Standards; Seasons; Taq Polymerase
PubMed: 24614533
DOI: 10.1371/journal.pone.0091104 -
Roczniki Panstwowego Zakladu Higieny 2015Peaches, sour cherries, nectarines, apricots, plums and cherries are fruit commonly known as "stone fruit". Their nutritional properties namely, vitamins, minerals,...
BACKGROUND
Peaches, sour cherries, nectarines, apricots, plums and cherries are fruit commonly known as "stone fruit". Their nutritional properties namely, vitamins, minerals, fiber and numerous microelements, make them a very important component of human diet. As fruit trees can be attacked by numerous diseases and pests, chemical protection of these crops is used. Therefore, it is important that the relevant governmental agencies or institutions ensure correct application of pesticides.
OBJECTIVE
The aim of the study was to evaluate the occurrence of pesticide residues in stone fruits south-eastern region of Poland in 2012-2014 in order to provide data to estimate health risk to consumers.
MATERIAL AND METHODS
Validated analytical methods based on liquid / liquid extraction coupled with gas chromatography with electron capture and nitrogen phosphorus detection (GC-ECD/NPD) and spectrophotometry (dithiocarbamates residues) were used for the analysis. 92 samples of stone fruits were tested for the presence of pesticide residues.
RESULTS
13 of all samples (14%) contained pesticide residues. 7 active substances were detected, including 5 fungicides: boscalide, bupirimate, difenoconazole, dithiocarbamates and captan, and 2 insecticides: cypermethrin and pirimicarb. In the analysed samples, the use of not recommended plant protection products in orchard crops were found. However, neither maximum residue levels (MRLs) recommended by the Regulation (EC) No 396/2005 were exceeded nor pesticides being unapproved by the Regulation (EC) No 1107/2009 detected in the analysed samples.
CONCLUSIONS
Lack of plant protection products for control specific diseases or pests in crops results in the use of formulations not recommended for use in certain orchard crops. On a basis of results reported in previous years it can be concluded that occurrence of pesticide residues in stone fruit samples dropped significantly.
Topics: Bridged Bicyclo Compounds; Dioxolanes; Endosulfan; Food Contamination; Fruit; Humans; Insecticides; Maximum Allowable Concentration; Pesticide Residues; Pesticides; Poland; Pyrimidines; Thiocarbamates; Triazoles
PubMed: 26400116
DOI: No ID Found -
Arhiv Za Higijenu Rada I Toksikologiju Dec 2016The aim of the study was to evaluate genotoxic effects of Pirimor-50®, a pirimicarb-based formulation (50 % active ingredient), in human lymphocyte cultures and Vicia...
Genotoxic effects of the carbamate insecticide Pirimor-50® in Vicia faba root tip meristems and human lymphocyte culture after direct application and treatment with its metabolic extracts.
The aim of the study was to evaluate genotoxic effects of Pirimor-50®, a pirimicarb-based formulation (50 % active ingredient), in human lymphocyte cultures and Vicia faba root meristems. Furthermore, the objective was to examine a combined influence of insecticide treatment with mammalian microsomal S9 and vegetal S10 metabolic fractions or S10 mix metabolic transformation extracts (after Vicia faba primary roots treatment with Pirimor-50®). We used sister chromatid exchange assay-SCE and measured cell cycle progression and proliferation (proportion of M1-M3 metaphases and replication index ratio-RI). Two processes were used for plant promutagen activation: in vivo activation-Pirimor-50® was applied for 4 h to the plant and then S10 mix was added to lymphocytes; and, in vitro activation-lymphocytes were treated with Pirimor-50® and S10 or S9 for 2 h. Direct treatment induced significantly higher SCE frequencies in meristems at 0.01 mg mL-1. In lymphocytes, significantly higher SCE was at 1 mg mL-1 with decrease in RI and M1-M3 metaphase proportions at 0.5 mg mL-1 and cell division stop at 2.5 mg mL1. S10 mix lymphocyte treatment showed significantly elevated SCE values at 2-2.5 mg mL-1, with cell death at 3 mg mL-1. Lymphocyte treatment with Pirimor-50® together with S9 or S10 showed slightly elevated SCE frequency but had a significant influence on RI decrease, with lowest values in S9 treatment. Since no data are available on the genotoxicity of Pirimor-50®, this study is one of the first to evaluate and compare its direct effect in two bioassays, animal and vegetal, and also the effect of plant and animal metabolism on its genotoxic potential.
Topics: Carbamates; Cell Proliferation; Cells, Cultured; DNA Damage; Humans; Insecticides; Lymphocytes; Mutagenicity Tests; Plant Roots; Sister Chromatid Exchange; Vicia faba
PubMed: 28033107
DOI: 10.1515/aiht-2016-67-2809 -
PloS One 2012Insecticide resistance is one of the best examples of rapid micro-evolution found in nature. Since the development of the first synthetic insecticide in 1939, humans...
BACKGROUND
Insecticide resistance is one of the best examples of rapid micro-evolution found in nature. Since the development of the first synthetic insecticide in 1939, humans have invested considerable effort to stay ahead of resistance phenotypes that repeatedly develop in insects. Aphids are a group of insects that have become global pests in agriculture and frequently exhibit insecticide resistance. The green peach aphid, Myzus persicae, has developed resistance to at least seventy different synthetic compounds, and different insecticide resistance mechanisms have been reported worldwide.
METHODOLOGY/PRINCIPAL FINDINGS
To further characterize this resistance, we analyzed genome-wide transcriptional responses in three genotypes of M. persicae, each exhibiting different resistance mechanisms, in response to an anti-cholinesterase insecticide. The sensitive genotype (exhibiting no resistance mechanism) responded to the insecticide by up-regulating 183 genes primarily ones related to energy metabolism, detoxifying enzymes, proteins of extracellular transport, peptidases and cuticular proteins. The second genotype (resistant through a kdr sodium channel mutation), up-regulated 17 genes coding for detoxifying enzymes, peptidase and cuticular proteins. Finally, a multiply resistant genotype (carrying kdr and a modified acetylcholinesterase), up-regulated only 7 genes, appears not to require induced insecticide detoxification, and instead down-regulated many genes.
CONCLUSIONS/SIGNIFICANCE
This study suggests strongly that insecticide resistance in M. persicae is more complex that has been described, with the participation of a broad array of resistance mechanisms. The sensitive genotype exhibited the highest transcriptional plasticity, accounting for the wide range of potential adaptations to insecticides that this species can evolve. In contrast, the multiply resistant genotype exhibited a low transcriptional plasticity, even for the expression of genes encoding enzymes involved in insecticide detoxification. Our results emphasize the value of microarray studies to search for regulated genes in insects, but also highlights the many ways those different genotypes can assemble resistant phenotypes depending on the environmental pressure.
Topics: Animals; Aphids; Carbamates; Gene Expression Regulation; Genome, Insect; Genotype; Humans; Insect Proteins; Insecticide Resistance; Insecticides; Oligonucleotide Array Sequence Analysis; Prunus; Pyrimidines; Reverse Transcriptase Polymerase Chain Reaction; Transcriptome
PubMed: 22685538
DOI: 10.1371/journal.pone.0036366 -
EXCLI Journal 2015A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health and safety. Here, a paper-based sensor combined with a...
A dramatic increase in pesticide usage in agriculture highlights the need for on-site monitoring for public health and safety. Here, a paper-based sensor combined with a wet system was developed for the simple and rapid screening of organophosphate (OP) and carbamate (CM) pesticides based on the inhibition of acetylcholinesterase (AChE). The paper-based sensor was designed as a foldable device consisting of a cover and detection sheets pre-prepared with indoxyl acetate and AChE, respectively. The paper-based sensor requires only the incubation of a sample on the test zone for 10 minutes, followed by closing of the foldable sheet to initiate the enzymatic reaction. Importantly, the buffer loading hole was additionally designed on the cover sheet to facilitate the interaction of the coated substrate and the immobilized enzyme. This subsequently facilitates the mixing of indoxyl acetate with AChE, resulting in the improved analytical performance of the sensor. The absence or decrease in blue color produced by the AChE hydrolysis of indoxyl acetate can be observed in the presence of OPs and CMs. Under optimized conditions and using image analysis, the limit of detection (LOD) of carbofuran, dichlorvos, carbaryl, paraoxon, and pirimicarb are 0.003, 0.3, 0.5, 0.6, and 0.6 ppm, respectively. The assay could be applied to determine OP and CM residues in spiked food samples. Visual interpretation of the color signal was clearly observed at the concentration of 5 mg/kg. Furthermore, a self-contained sample pre-concentration approach greatly enhanced the detection sensitivity. The paper-based device developed here is low-cost, requires minimal reagents and is easy to handle. As such, it would be practically useful for pesticide screening by non-professional end-users.
PubMed: 26417364
DOI: 10.17179/excli2014-684 -
Mededelingen (Rijksuniversiteit Te... 2001Vegetable open field areas increased for 15 years in Wallonia, mainly in Hesbaye. To be in accordance with quality standards, especially in terms of agro-chimical...
Vegetable open field areas increased for 15 years in Wallonia, mainly in Hesbaye. To be in accordance with quality standards, especially in terms of agro-chimical residues (R.M.L.), biological pest control was developed and allowed to reduce the insecticide use, leading to have safer fresh products. Among cultivated species in Wallonia, leguminous crops represent more than 85% of the vegetable production. To assess the impact of insecticide treatment on both pests (mainly aphids) and beneficial insects (predators and parasitoïds), broad bean (Vicia faba L.) fields were investigated during all the production duration. Twelve fields between Waremme and Hannut were visited weakly from May to July. In each field, control untreated and treated plots were investigated. Insects were caught using yellow traps and determined until the family level. Approximately 90.000 insects belonging to 59 major families (99% of captures) and 64 minor families were identified. These results showed that biodiversity in terms of family numbers was significantly higher in unsprayed plots. In addition, biodiversity and biomass (insect density) increased gradually during the season. Evaluation of pest and beneficial diversity and density was discussed in relation to aphicid (lambda-cyhalothrin, pirimicarb) treatments and the development of I.P.M. program in vegetable crops.
Topics: Animals; Belgium; Biomass; Female; Insecta; Insecticides; Male; Pest Control, Biological; Population Density; Population Dynamics; Vegetables; Vicia faba
PubMed: 12425061
DOI: No ID Found -
PloS One 2012Among herbivorous insects that have exploited agro-ecosystems, the peach-potato aphid, Myzus persicae, is recognized as one of the most important agricultural pests...
BACKGROUND
Among herbivorous insects that have exploited agro-ecosystems, the peach-potato aphid, Myzus persicae, is recognized as one of the most important agricultural pests worldwide. Uses over 400 plant species and has evolved different insecticides resistance mechanisms. As M. persicae feeds upon a huge diversity of hosts, it has been exposed to a wide variety of plant allelochemicals, which probably have promoted a wide range of detoxification systems.
METHODOLOGY/PRINCIPAL FINDINGS
In this work we (i) evaluated whether insecticide resistance mutations (IRM) in M. persicae can give an advantage in terms of reproductive fitness when aphids face two hosts, pepper (Capsicum annuum) a suitable host and radish (Raphanus sativus) the unfavorable host and (ii) examined the transcriptional expression of six genes that are known to be up-regulated in response to insecticides. Our results show a significant interaction between host and IRM on the intrinsic rate of increase (r(m)). Susceptible genotypes (not carrying insensitivity mutations) had a higher r(m) on pepper, and the transcriptional levels of five genes increased on radish. The r(m) relationship was reversed on the unfavorable host; genotypes with multiple IRM exhibited higher r(m), without altering the transcriptional levels of the studied genes. Genotypes with one IRM kept a similar r(m) on both hosts, but they increased the transcriptional levels of two genes.
CONCLUSIONS/SIGNIFICANCE
Although we have studied only nine genotypes, overall our results are in agreement with the general idea that allelochemical detoxification systems could constitute a pre-adaptation for the development of insecticide resistance. Genotypes carrying IRM exhibited a higher r(m) than susceptible genotypes on radish, the more unfavorable host. Susceptible genotypes should be able to tolerate the defended host by up-regulating some metabolic genes that are also responding to insecticides. Hence, our results suggest that the trade-off among resistance mechanisms might be quite complex, with a multiplicity of costs and benefits depending on the environment.
Topics: Adaptation, Physiological; Animals; Aphids; Capsicum; Carbamates; Carboxylesterase; Cathepsin B; Cytochrome P-450 Enzyme System; Evolution, Molecular; Gene Expression Regulation; Genotype; Glutathione Transferase; HSP70 Heat-Shock Proteins; Host Specificity; Humans; Insect Proteins; Insecticide Resistance; Insecticides; Isoenzymes; Mutation; Prunus; Pyrimidines; Raphanus; Reverse Transcriptase Polymerase Chain Reaction; Up-Regulation
PubMed: 22685539
DOI: 10.1371/journal.pone.0036810 -
Roczniki Panstwowego Zakladu Higieny 2008The aim of this paper was to present occurrence of plant protection product residues in apples in 2007. Gas chromatographic and spectroscopy methods were used. The most...
The aim of this paper was to present occurrence of plant protection product residues in apples in 2007. Gas chromatographic and spectroscopy methods were used. The most frequently found were fungicides: dithiocarbamate residues (18% of the analysed samples), captan residues (13%), pyrimethanil residues (6%) and insecticides: chlorpiryfos residues (6%), diazinon residues (6%) and pirimicarb residues (5%). 5.6% of analysed samples exceeded the national Maximum Residue Level established for apples. Violations were found for: flusilazole (n = 2), propiconazole (n = 2), cyprodinil (n = 1), dimethoate (n = 1), fenitrothion (n = 1).
Topics: Bridged Bicyclo Compounds; Chromatography, High Pressure Liquid; Environmental Exposure; Environmental Monitoring; Food Contamination; Fruit; Fungicides, Industrial; Humans; Insecticides; Pesticide Residues; Poland; Pyrimidines
PubMed: 19143426
DOI: No ID Found -
Journal of Chromatography. A Jun 2007We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different...
Development and validation of a multi-residue method for pesticide determination in honey using on-column liquid-liquid extraction and liquid chromatography-tandem mass spectrometry.
We report on the development and validation under ISO 17025 criteria of a multi-residue confirmatory method to identify and quantify 17 widely chemically different pesticides (insecticides: Carbofuran, Methiocarb, Pirimicarb, Dimethoate, Fipronil, Imidacloprid; herbicides: Amidosulfuron, Rimsulfuron, Atrazine, Simazine, Chloroturon, Linuron, Isoxaflutole, Metosulam; fungicides: Diethofencarb) and 2 metabolites (Methiocarb sulfoxide and 2-Hydroxytertbutylazine) in honey. This method is based on an on-column liquid-liquid extraction (OCLLE) using diatomaceous earth as inert solid support and liquid chromatography (LC) coupled to mass spectrometry (MS) operating in tandem mode (MS/MS). Method specificity is ensured by checking retention time and theoretical ratio between two transitions from a single precursor ion. Linearity is demonstrated all along the range of concentration that was investigated, from 0.1 to 20 ng g(-1) raw honey, with correlation coefficients ranging from 0.921 to 0.999, depending on chemicals. Recovery rates obtained on home-made quality control samples are between 71 and 90%, well above the range defined by the EC/657/2002 document, but in the range we had fixed to ensure proper quantification, as levels found in real samples could not be corrected for recovery rates. Reproducibility is found to be between 8 and 27%. Calculated CCalpha and CCbeta (0.0002-0.943 ng g(-1) for CCalpha, and 0.0002-1.232 ng g(-1) for CCbeta) show the good sensitivity attained by this multi-residue analytical method. The robustness of the method has been tested in analyzing more than 100 raw honey samples collected from different areas in Belgium, as well as some wax and bee samples, with a slightly adapted procedure.
Topics: Chromatography, Liquid; Honey; Pesticide Residues; Reproducibility of Results; Sensitivity and Specificity; Tandem Mass Spectrometry
PubMed: 17416380
DOI: 10.1016/j.chroma.2007.03.035