OP Pesticides Research Articles

Ambient long-term exposure to organophosphorus pesticides and the human gut microbiome: an observational study

BackgroundOrganophosphorus pesticides (OP) have been associated with various human health conditions. Animal experiments and in-vitro models suggested that OP may also affect the gut microbiota. We examined associations between ambient chronic exposure to OP and gut microbial changes in humans.MethodsWe recruited 190 participants from a community-based epidemiologic study of Parkinson’s disease living in a region known for heavy agricultural pesticide use in California. Of these, 61% of participants had Parkinson’s disease and their mean age was 72 years. Microbiome and predicted metagenome data were generated by 16S rRNA gene sequencing of fecal samples. Ambient long-term OP exposures were assessed using pesticide application records combined with residential addresses in a geographic information system. We examined gut microbiome differences due to OP exposures, specifically differences in microbial diversity based on the Shannon index and Bray–Curtis dissimilarities, and differential taxa abundance and predicted Metacyc pathway expression relying on regression models and adjusting for potential confounders.ResultsOP exposure was not associated with alpha or beta diversity of the gut microbiome. However, the predicted metagenome was sparser and less evenly expressed among those highly exposed to OP (p = 0.04). Additionally, we found that the abundance of two bacterial families, 22 genera, and the predicted expression of 34 Metacyc pathways were associated with long-term OP exposure. These pathways included perturbed processes related to cellular respiration, increased biosynthesis and degradation of compounds related to bacterial wall structure, increased biosynthesis of RNA/DNA precursors, and decreased synthesis of Vitamin B1 and B6.ConclusionIn support of previous animal studies and in-vitro findings, our results suggest that ambient chronic OP pesticide exposure alters gut microbiome composition and its predicted metabolism in humans.

A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures

Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.

Impact of organophosphate pesticides exposure on human semen parameters and testosterone: a systematic review and meta-analysis.

Organophosphate (OP) pesticides have been associated with a decline in semen quality, although there are still considerable arguments about the magnitude of the association. This study provides a systematic review and meta-analysis of the impacts of OP pesticides on semen quality and male reproductive hormones. This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocols. Strategic search was conducted using combined text words as search terms. The eligibility criteria were developed based on Population, Exposure, Comparator, Outcome, and Study designs (PECOS) framework. Relevant data were extracted, risk of bias was evaluated by The Office of Health Assessment and Translation (OHAT) tool, and certainty of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group guidelines. Quantitative meta-analysis was performed by using Review Manager. A total of 766 male subjects (349 exposed to OP pesticides and 417 unexposed controls) were included in the meta-analysis. There was no significant difference in the ejaculate volume, seminal fluid volume, sperm multiple anomaly index, sperm, and leukocytes levels of the OP-exposed subjects compared to the control. In addition, OP pesticides exposure did not significantly affect serum concentrations of FSH, LH, and testosterone in subjects who were exposed to OP pesticides compared to their unexposed counterparts. However, we found a significant reduction in the sperm count, sperm concentration, progressive sperm motility, total sperm motility, and normal sperm morphology of OP pesticides-exposed subjects compared to the unexposed subjects. However, after subtype and sensitivity analyses, exposure to OP pesticides did not reduce sperm count. Also, after sensitivity analysis, OP pesticides exposure did not alter progressive sperm motility. This study demonstrates that OP pesticides exposure reduced sperm count, concentration, total and progressive motility, and normal sperm morphology, possibly via a testosterone-independent mechanism.

Development and Validation of a New UFLC-MS/MS Method for the Detection of Organophosphate Pesticide Metabolites in Urine.

To monitor human exposure to pesticides, experts commonly measure their metabolites in urine, particularly dialkyl phosphates (DAPs), which include diethyl phosphate (DEP), Diethyl thiophosphate (DETP), diethyl dithiophosphate (DEDTP), dimethyl phosphate (DMP), dimethyl thiophosphate (DMTP) and dimethyl dithiophosphate (DMDTP)to monitor the metabolites of organophosphates. These DAP metabolites are a urinary biomarker for assessing pesticide exposure and potential health risks. This study presented a new screening method combining ultrafast liquid chromatography with tandem mass spectrometry (UFLC-MS/MS) to detect six DAP metabolites in human urine. The study also compared standard sample extraction methods, namely, liquid-liquid extraction (LLE); quick, easy, cheap, effective, ruggedand safe (QuEChERS); and lyophilization. After a comprehensive analysis of the methods used to extract the analytes, including recovery rate, repeatability and reproducibility, the liquid-liquid extraction (LLE) method was found to be the best. It had a high recovery rate, was easy to handle, required less sample volume and had a short extraction time. Therefore, the LLE method was chosen for further analysis. The results showed excellent performance with high recoveries between 93% and 102%, precise repeatability (RSD) between 0.62% and 5.46% and acceptable reproducibility values (RSD) between 0.80% and 11.33%. The method also had limits of detection (LOD) ranging from 0.0201 ng/mL to 0.0697 ng/mL and limits of quantification (LOQ) ranging from 0.0609 ng/mL to 0.2112 ng/mL. Furthermore, the UFLC-MS/MS method was validated based on the SANTE guidance and successfully analyzed 150 urine samples from farmers and non-farmers. This validated method proved useful for biomonitoring studies focusing on OP pesticide exposure. It offers several advantages, such as a reduced need for samples, chemicals and materials, and a shorter analysis time. The method is sensitive and selective in detecting metabolites in human urine, making it a valuable approach for the practical and efficient assessment of pesticide exposure.

P-009 Impact of organophosphate pesticide exposure on human semen quality and circulating testosterone: a systematic review and meta-analysis

Abstract Study question Does exposure to organophosphate pesticides (OP pesticides) alter human semen quality and circulating testosterone levels? Summary answer Exposure to OP pesticides reduced sperm count, concentration, total and progressive motility, and normal sperm morphology, possibly via a testosterone-independent mechanism. What is known already OP pesticides have been associated with a decline in semen quality, although there are still considerable arguments about the magnitude of the association. Also, human data on semen quality and male reproductive hormones in association with OP pesticide exposure is limited and inconsistent. Study design, size, duration This study provides a systematic review and meta-analysis of the impacts of OP pesticide on semen quality and male reproductive hormones. Participants/materials, setting, methods This study was conducted according to PRISMA guidelines. Following a pre-defined strategic protocol, 1, 001 studies were screened and 9 articles were identified as eligible for this study. Two of the studies were from China, and one each from Japan, Peru, France, Mexico, Malaysia, Venezuela, and Iran. Two of the studies did not specify the types of OP pesticide used, while the remaining 7 did. Main results and the role of chance A total of 766 male subjects (349 exposed to OP pesticide and 417 unexposed controls) were included in the meta-analysis. There was no significant difference in the ejaculate volume, seminal fluid volume, sperm multiple anomaly index, and leukocytes levels of the OP-exposed subjects compared to the control. In addition, OP pesticide exposure did not significantly affect serum concentrations of FSH, LH, and testosterone in subjects who were exposed to OP pesticide compared to their unexposed counterparts. However, we found a significant reduction in the sperm count, sperm concentration, progressive sperm motility, total sperm motility, and normal sperm morphology of OP pesticide-exposed subjects compared to the unexposed subjects. However, after subtype and sensitivity analyses, exposure to OP pesticide did not significantly reduce sperm count. In addition, after sensitivity analysis, OP pesticide exposure did not significantly alter progressive sperm motility. Limitations, reasons for caution The non-inclusion of non-English publications in this study and the scarcity of well-designed studies to be included might have limited the pooled sample size and inadequately explored the impacts of OP. Also, the included studies are from a few countries, which may not necessarily be a good global representative. Wider implications of the findings The present comprehensive meta-analysis clearly demonstrates that exposure to OP pesticide causes reduced sperm count, concentration, total and progressive motility, and normal sperm morphology, possibly via a testosterone-independent mechanism. These findings strengthen existing evidence in the literature on the negative impacts OP pesticide exposure on semen quality. Trial registration number Not applicable

An ultrasensitive "mix-and-detect" kind of fluorescent biosensor for malaoxon detection using the AChE-ATCh-Ag-GO system.

Malaoxon, a highly toxic metabolite of malathion, can lead to severe harm or death if ingested. This study introduces a rapid and innovative fluorescent biosensor that relies on acetylcholinesterase (AChE) inhibition for detecting malaoxon using Ag-GO nanohybrid. The synthesized nanomaterials (GO, Ag-GO) were evaluated with multiple characterization methods to confirm their elemental composition, morphology, and crystalline structure. The fabricated biosensor works by utilizing AChE to catalyze the substrate acetylthiocholine (ATCh), which generates positively charged thiocholine (TCh) and triggers citrate-coated AgNP aggregation on the GO sheet, leading to an increase in fluorescence emission at 423 nm. However, the presence of malaoxon inhibits the AChE action and reduces the production of TCh, resulting in a decrease in fluorescence emission intensity. This mechanism allows the biosensor to detect a wide range of malaoxon concentrations with excellent linearity and low LOD and LOQ values of 0.001 pM to 1000 pM, 0.9 fM, and 3 fM, respectively. The biosensor also demonstrated superior inhibitory efficacy towards malaoxon compared to other OP pesticides, indicating its resistance to external influences. In practical sample testing, the biosensor displayed recoveries of over 98% with extremely low RSD% values. Based on the results obtained from the study, it can be concluded that the developed biosensor has the potential to be used in various real-world applications for detecting malaoxon in food, and water samples, with high sensitivity, accuracy, and reliability.

Determination of inhabitation percentage of pesticide residue in vegetables with the help of spectrophotometer

The common types of pesticides such as carbamate and organophosphate are cause serious health issues for consumers. Although these have several benefits to preserve fruits, vegetables, and cereals as well as better yield. The farmers should be aware during the used of the pesticides in nature of the pesticides, ratio of pesticide to land area, and waiting period for edible vegetable. This study focused on the quantitative analysis of rapid bioassay of spectrophotometric for inhabitation of pesticides occurs in the vegetables. The nine different vegetables were collected from six places and analyzed then compared with the standard result. Eight vegetable samples provided green coloured indication and one indicated yellow colour by spectrophotometry. Furthermore, the percentage of Op and Ca pesticide residue is below 35%, which indicates such vegetables are edible. But for cucumber the Op was found in the 35-45% range and resulted in yellow colour, it indicates that the vegetables are non-edible. For cucumber, it takes to quarantine for 2-3 days after that the pesticide could be reduced and safe for consumption. It is clear from this study that no vegetable in the local market has a maximum percentage level of pesticide Op and Ca. However, most of the vegetables available in the market of Sudurpaschim province are safe to consume.

Prenatal exposure to organophosphate pesticides and autism spectrum disorders in 11-year-old children in the French PELAGIE cohort

BackgroundOrganophosphate (OP) pesticides act by inhibiting acetylcholinesterase activity at synaptic junctions and have already been linked with deleterious effects on neurodevelopment, including autism spectrum disorders (ASD). ObjectivesTo investigate the association of prenatal exposure to OP pesticides with traits related to ASD in 11-year-old children. MethodsThe “Childhood Autism Spectrum Test” (CAST) parent questionnaire was used to screen for autistic traits in 792 children from the French PELAGIE cohort. Prenatal maternal urine samples were collected <19 weeks of gestation in which metabolites of organophosphate insecticides were assessed for 185 of them. Negative binomial regression models were performed to explore the association between the CAST score and 8 groups of urine components, adjusted for potential ASD risk factors. ResultsIn these urine samples, dialkylphosphates (DAP) were detected most often (>80%), terbufos and its metabolites least often (<10%). No association with ASD was found for DAP, terbufos or its metabolites. Incidence rate ratios (IRRs) increased with maternal urinary diazinon concentrations, from 1.11 (95% CI: 0.87–1.42) to 1.17 (95% CI: 0.94–1.46). Higher CAST scores were statistically significantly associated with the maternal urine samples in which chlorpyrifos or two of its metabolites (chlorpyrifos-oxon and 3,5,6-trichloro-2-pyridinol) were detected. The IRR for exposure to chlorpyrifos or chlorpyrifos-oxon was 1.27 (95%CI: 1.05–1.52) among all children, and 1.39 (95%CI: 1.07–1.82) among boys. ConclusionThese findings suggest an increase in autistic traits among 11-year-old children in association with prenatal maternal exposure to chlorpyrifos and possibly diazinon. These associations were previously suspected in the literature, in particular for chlorpyrifos. Further work establishing the causal mechanisms behind these risk association is needed.

Ag-EDTA-Zr and Au-EDTA-Zr Nanocomposites for the Quantitative Determination of Some Organophosphate Pesticides in Water and Tomatoes.

Organophosphate pesticides (OP) pose risks to health and the environment, and monitoring them is an urgent task. Development of a method for their determination in water and food. A simple photometric method for the determination of some OPs was demonstrated. Ag-EDTA-Zr and Au-EDTA-Zr nanoparticles were synthesized and were applied for the determination of some OPs (dimethoate, chlorpyrifos, and diazinon). It was demonstrated that silver nanoparticles provide more sensitivity in comparison to gold nanoparticles. As a result, Ag-EDTA-Zr nanoparticles were further applied for the determination of these pesticides in tomatoes. The lowest detectable concentrations for dimethoate, diazinon, and chlorpyrifos in water reached 0.1 (SD 0.082), 0.4 (SD 0.075), and 0.4 mg/L (SD 0.088), respectively, whereas in tomato the lowest detectable concentrations for these pesticides were 0.5 (SD 0.789), 2 (SD 0.085), and 0.5 mg/L (SD 0.088). The sensitivity of detection in tomatoes is lower than in water; however, these concentrations are comparable with allowable concentrations of OP pesticides. A novel approach for quantitative detection of OPs was developed. Ag-EDTA-Zr and Au-EDTA-Zr nanocomposites interact with these pesticides, and, as a result, optical changes of these nanoparticles take place. These changes correlate with the concentration of pesticides.

Localized Surface Plasmon Resonance-Based Colorimetric Assay Featuring Thiol-Capped Au Nanoparticles Combined with a Mobile Application for On-Site Parathion Organophosphate Pesticide Detection

In this study, we employed a dual strategy for parathion organophosphate pesticide (parathion) detection; first, we used a localized surface plasmon resonance (LSPR)-based colorimetric sensor featuring thiol-capped Au NPs, namely cysteine (Cys)@Au NPs, 11-mercaptoundecanoic acid (11-MUA)@Au NPs, and glutathione (GSH)@Au NPs, via acetylcholinesterase (ACHE) and acetylthiocholine (ATCH) enzyme-mediated hydrolysis reactions; second, we developed a color analysis toxicity-sensing app (Toxin APP). Positively charged thiocholine (TCH) molecules, which were continuously generated via hydrolysis, subsequently conjugated with thiol-capped Au NPs, causing Au NP aggregation through electrostatic attractions. The degree of aggregation of the thiol-capped Au NPs was influenced by parathion concentrations in the range 0 to 108 ppt, because parathion acted as an ACHE inhibitor by controlling the amount of TCH generated. Based on the values of LSPR absorbance ratio, the limits of detection (LODs) of three types thiol-capped Au NPs were determined to be 100 ppt using ultraviolet-visible spectroscopy measurements. However, the aggregation efficiency of GSH@Au NPs was lower than that of the others regarding gradual changes in their color and LSPR absorbance band. Furthermore, we designed Toxin APP for color analysis which consists of three modules: processing, database collection, and communication. Toxin APP could on-site and precisely detect the color changes of GSH@Au NPs at parathion concentrations in the ranges of 100 ppt to 1, 10, and 100 ppm and could distinguish between OP and non-OP pesticides (e.g., fipronil) in tap water samples with high sensitivity and selectivity. Moreover, the concentration of residual parathion in real samples (tomato and strawberry) was quantified based on the color changes of GSH@Au NPs detected using Toxin APP. Therefore, the combination of an LSPR-based colorimetric assay and Toxin APP can be a reliable method for the facile and rapid detection of parathion in food and water samples.

Overview of a bioremediation tool: organophosphorus hydrolase and its significant application in the food, environmental, and therapy fields.

In the past decades, the organophosphorus compounds had been widely used in the environment and food industries as pesticides. Owing to the life-threatening and long-lasting problems of organophosphorus insecticide (OPs), an effective detection and removal of OPs have garnered growing attention both in the scientific and practical fields in recent years. Bacterial organophosphorus hydrolases (OPHs) have been extensively studied due to their high specific activity against OPs. OPH could efficiently hydrolyze a broad range of substrates both including the OP pesticides and some nerve agents, suggesting a great potential for the remediation of OPs. In this review, the microbial identification, molecular modification, and practical application of OPHs were comprehensively discussed.Key points• Microbial OPH is a significant bioremediation tool against OPs.• Identification and molecular modification of OPH was discussed in detail.• The applications of OPH in food, environmental, and therapy fields are presented.

Organophosphate pesticides and progression of chronic kidney disease among children: A prospective cohort study

BackgroundGrowing evidence suggests that exposure to environmental chemicals, such as pesticides, impacts renal function and chronic kidney disease (CKD). However, it is not clear if pesticides may affect CKD progression and no studies exist in children. ObjectivesThe objective of this study was to examine associations between serially measured urinary OP pesticide metabolites and clinical and laboratory measures of kidney function over time among children with CKD. MethodsThis study used data on 618 participants enrolled in the CKD in Children study (CKiD), a cohort study of pediatric CKD patients from the US and Canada. Children were followed over an average of 3.0 years (standard deviation (SD) = 1.6) between 2005 and 2015. In serially collected urine samples over time, six nonspecific dialkyl phosphate (DAP) metabolites of OP pesticides were measured. Biomarkers of tubular injury (kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL)) and oxidant stress (8-hydroxy-2′-deoxyguanosine (8-OHdG) and F2-isoprostane) were determined in the same specimens. Estimated glomerular filtration rate (eGFR), proteinuria, and blood pressure were assessed annually. ResultsDAPs were associated with increased KIM-1 and 8-OHdG throughout follow-up. A standard deviation increase in ∑diethyl metabolites was associated with increases of 11.9% (95% Confidence Interval (CI): 4.8%, 19.4%) and 13.2% (95% CI: 9.3%, 17.2%) in KIM-1 and 8-OHdG over time, respectively. DAPs were associated with lower eGFR at baseline and higher eGFR over subsequent years. ConclusionsThese findings provide preliminary evidence suggesting that urinary DAP metabolites are associated with subclinical kidney injury among children with CKD, which may signal the potential for clinical events to manifest in the future. The results from this study are significant from both a clinical and public health perspective, given that OP pesticide exposure is a modifiable risk factor.

Abatement of organic and inorganic pollutants from drinking water by using commercial and laboratory-synthesized zinc oxide nanoparticles

ZnO nanoparticles have been synthesized and applied for the removal of different environmental pollutants in the present study. Combustion method is used for the preparation of ZnO NPs. X-Ray diffraction pattern reveals the crystallinity of the nanoparticles, where SEM and TEM images displayed that ZnO NPs were of size less than 100 nm and nearly spherical in shape. UV–Vis and IR spectra revealed the formation of ZnO NPs. Adsorption and advanced oxidation processes were employed for the removal/degradation of trace elements/pesticide. UV reactor containing 1 UV rod of 11 W (Philips) was used for the photocatalytic degradation of pesticide. ICP–OES and GC–MS techniques were used for the further quantitative analysis of trace elements and OP pesticide—monocrotophos, respectively. The analysis shows the 88% degradation of monocrotophos when subjected to UV light in the reaction chamber for 120 min at a pH 4 when 2 g of nanocatalyst is applied. However, the removal of trace element Arsenic shows linear adsorption as compared to Cd and Se. The removal efficiency of ZnO nanoparticles for Cd and Se was 36% and 64%, respectively, after 120 min. The synthesized nanoparticles are more effective than the commercially available ones.

A mixed-methods study of pesticide exposures in Breastmilk and Community & Lactating Women\u2019s perspectives from Haryana, India

BackgroundPopulation growth which has resulted in a need for increased crop yields to sustain food security, in addition to the effects of climate change, have led to the widespread use of chemical pesticides. The indiscriminate use of pesticides has in turn led to contamination of the environment, food commodities and bioaccumulation in human tissues, particularly in agrarian regions of India including the northern state of Haryana.MethodsWe conducted a pilot screening study to investigate the presence of organochlorine, organophosphate, and pyrethroid pesticides in breastmilk samples (n = 75) from Haryana, India. Pesticide analyses were conducted using gas chromatography mass spectrometry (GC-MS) for OC and OP pesticides and GC-electron capture detector for pyrethroids. The study was complemented by a qualitative evaluation of maternal and community perceptions, knowledge, attitudes and practices associated with pesticide use and risk of exposure (n = 30 in-depth interviews; n = 9 focus group discussions).ResultsAnalysis of breastmilk showed the presence of p,p’-dichlorodiphenyltrichloroethane (DDT) and p,p’-dichlorodiphenyldichloroethylene (DDE) in 4% (range: <LOQ - 28 μg/L) and 5% (range: < LOQ – 107 μg/L) of samples, respectively. No other pesticides were detected.Our qualitative findings showed that community members commonly held perceptions of pesticides as medicines and poison but acknowledged their widespread use to ensure crop yields. Given the gendered engagement in farming in this setting, lactating women in study communities do not directly handle chemical pesticides, thus lowering risk of inhalation and dermal exposure.ConclusionsIn our small sample, breastmilk pesticide concentrations were low and did not pose a risk to infants. Based on the persistent nature of many organic pollutants and reported widespread use, we recommend more comprehensive and longitudinal investigation of upstream pesticide contamination in the food supply and exposures among mothers and children.Trial registrationCTRI/2017/01/007636, Date Registered: 06/01/2017.CTRI website: http://ctri.nic.in/Clinicaltrials/pdf_generate.php?trialid=17249&EncHid=&modid=&compid=%27,%2717249det%27

Exposure to pesticides, their incarnation during pregnancy and their effect on the neurodevelopment of infants, children of mothers of families residing in coffee growing areas: Cohort study, in southwest Antioquia

Background: The intensive agro-industry of coffee, with consumption of pesticides has ordered the course of life of men and women residents of municipalities in the territories of the Southwest Antioquia; Colombia. Colombia has a social processes of incarnation of pesticides that differ from other countries, with influence on neurodevelopment, unknown to date.Aim: To study the relationship between different pathways and patterns of incarnation of exposure to OP pesticides during pregnancy, and peripheral cholinesterase levels, with neurodevelopmental profiles in their infants inhabitants of eight (8) municipalities with conventional coffee growing systems.Methods: Prospective cohort and population base of 200 women. Data obtained through a survey during pregnancy. As biomarker of pesticide incarnation, erythrocyte acetylcholinesterase-AChE and serum butyrylcholinesterase-BChS were determined in three blood samples in the three trimesters of pregnancy The clinical and anthropometric data were obtained from the medical records, interviews and direct measurements of pregnant women and their children. Neurodevelopment was assessed in months 3 and 4 of postnatal life applying the neurodevelopmental scales of Bayley-IIIResults: Pregnant women who live in agro-farmer municipalities embody exposure to pesticides mainly because of their close ties not only to work but also to daily intensive agricultural production systems, a link that begins for most of them with their ancestors and could continue with their children. The trajectory of AChE during pregnancy described an ascending pattern throughout the trimesters of pregnancy and was not affected by the pathways of incarnation of pesticide exposure. On the contrary, the trajectory of the BChS during pregnancy described a downward trend throughout the quarters of pregnancy and was modified by the pathways of incarnation of pesticide exposure.In the development of neurodevelopment, a decrease in the fine motor domain score was related to exposure to pesticides in pregnant women.

Expression and physicochemical characterization of an N-terminal polyhistidine-tagged phosphotriesterase from the soil bacterium Brevundimonas diminuta

Abstract In this study, a truncated organophosphate-degrading (opd) gene encoding a Brevundimonas diminuta phosphotriesterase (BdPTE) without its leader peptide was artificially synthesized and cloned into the expression vector pQE-30 to yield pQE-BdPTE. The His6-tagged 37.8-kDa enzyme was purified from the cell-free extract of isopropyl thio-β- d -galactoside (IPTG)-induced E. coli M15 (pRep4) cells harboring pQE-BdPTE to near homogeneity by metal chelate affinity chromatography. The assay conditions for His6-tagged BdPTE activity were optimized at 60 °C, pH 8.0, and 1.0 mM Co2+ ion. Kinetic analysis of His6-tagged BdPTE-catalyzed hydrolysis of diethyl p-nitrophenyl phosphate (paraoxon-ethyl) showed that its Km and kcat values were 21.9 ± 1.4 μM and 311.6 ± 12.3 s−1, respectively. Also, the recombinant enzyme had the ability to efficiently degrade the two most commonly used OP pesticides, ethion and fenthion, in Taiwan. His6-tagged BdPTE with 1 mM Co2+ was very stable during the storage period of 35 days at 4 °C. Urea- and guanidine hydrochloride (GdnHCl)-induced denaturation studies showed that the purified enzyme had [denaturant]0.5,N–U values of 6.7 and 3.4 M, respectively. Notably, His6-tagged BdPTE did exhibit some degree of tolerance to a variety of water-miscible organic co-solvents. Dimethyl sulfoxide (DMSO), acetone, dimethylformamide (DMF), and ethanol were obviously harmful to the hydrolytic activity of the enzyme at concentrations above 50% (v/v), while acetonitrile was the highest tolerated co-solvent. The organic solvent-tolerant feature verifies His6-tagged BdPTE highly suitable as a remediation agent for the biodegradation of non-polar OP pesticides.

Isolation and characterization of organophosphorus phosphatases from Bacillus thuringiensis MB497 capable of degrading Chlorpyrifos, Triazophos and Dimethoate

In the current investigation, bacterial strain Bacillus thuringiensis MB497 was examined for production of intracellular and extracellular organophosphorus phosphatase (OPP) enzymes. This strain produced significant amount of extracellular acidic and alkaline phosphatases. Production of neutral phosphatase was negligible. Production of OPP was generally highest at pH 11 and at 45–50 °C. However, activity and stability of OPP was highest at 37 °C and reduced at higher temperatures. OPP production was decreased after 48 h of incubation. Largely, OPP activity was inhibited by SDS and EDTA and significantly enhanced by metals (Zn++, Cu++ and Cd++). Both acidic and alkaline OPPs were capable of bio-precipitation of selected metals (Ni, Mn, Cr and Cd) up to 86–100%. When used against 50 mg/l of three OP pesticides (Chlorpyrifos, Triazophos, and Dimethoate), 81–94.6% degradation of pesticides was observed by alkaline OPP, while acidic OPP showed less degradation (61–70.5%) within 30 min of incubation.

QUINALPHOS POISONING: A SURVIVOR'S CASE

Quinalphos is an organophosphorous compound that is highly toxic in nature and an inhibitor of cholinesterase. It is an insecticide available in liquid form, in different amounts such as 25% emulsifiable concentrate, 35% emulsifiable concentrate and commonly used for crops such as cotton, mustard, paddy, etc. The minimum dosage for use is 150-1500 ml. Organophosphate poisoning has been a leading cause of suicide attempts in developing countries. This study sheds light on a case in which quinalphos was mistakenly swallowed, causing side-effects of cholinesterase such as dry mouth, diarrhea, and salivation. Agri-farmers in contact with OP pesticides on a daily basis should be provided with information and guidance on the use of products to avoid damage.

Loop-mediated isothermal amplification technique: principle, development and wide application in food safety.

Food safety is a major and enduring challenge and has a profound impact on the quality of human life. Loop-mediated isothermal amplification (LAMP) is a relatively novel gene amplification method under isothermal conditions with rapidity, simplicity and high specificity. This review will describe the principles and development of the LAMP technique along with its advantages and disadvantages, such as LAMP integrated on classical microfluidic chips, paper-chips, electrochemical devices, nanomaterials and digital devices. Moreover, we will systematically and comprehensively review its applications in the field of food safety, such as in the detection of foodborne pathogens, allergens and organophosphorus pesticides and genetically modified organisms; finally its development trends in food safety will be discussed.

Evaluation of chlorpyrifos residue in breast milk and its metabolite in urine of mothers and their infants feeding exclusively by breast milk in north of Iran.

The most common method of combating insects in low-income communities and developing countries, is the use of insecticides. The use of organophosphate insecticides is increasing due to their low prices and availability on the market. Chlorpyrifos is a medium-risk insecticide for human. The widespread use of organophosphorus insecticides, especially chlorpyrifos, in residential homes has undoubtedly created many health concerns. Babies have a high sensitivity to pesticides and environmental contaminants because of their evolutionary status. On the other hand, the main source of infants' exposure who are breast-fed exclusively to environmental pollutants is through breast milk and oral contact with objects that are covered with dust and particles. In this cross-sectional study, the concentration of chlorpyrifos in breast milk and its metabolite in urine samples of mothers and their under six months infants, feeding exclusively by breast milk in north of Iran have been investigated. The demographic data was collected through interviewing with selected mothers and completion of prepared data collecting forms. The data were statistically analyzed to investigate the relationships between exposure of mothers and their infants to chlorpyrifos. The mean concentration of chlorpyrifos and its metabolite in mothers' urine and milk samples and infant's urines were 1.3 ± 0.6, 2.1 ± 1.4 and 1.4 ± 0.7μg/L, respectively. Also, the mean concentration of chlorpyrifos in the dust on the house floors was73.4 ± 49ng/g. There are good correlations between the mean values of chlorpyrifos concentrations and its metabolite in mother's milk and urine (r = 0.872, p = 0.001), and the mother's milk and infant's urine (r = 0.722, p = 0.001). Also, there was a significant correlation between the concentration of chlorpyrifos in floor dust and its metabolites in the infant's urine (r = 0.554, p = 0.001). Our study suggests that the infants are the recipient of concentrated forms of chlorpyrifos residues through breast milk and house dust and it is quite well known that OP pesticides are toxic and have different kinds of adverse health effects. However, further research needs to be done to determine what these chemicals are doing to our children.