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Toxics Apr 2023A total of 34 antibiotics from five major classes of antibiotics, including macrolides, sulfonamides, quinolones, tetracyclines and chloramphenicol, were considered as...
A total of 34 antibiotics from five major classes of antibiotics, including macrolides, sulfonamides, quinolones, tetracyclines and chloramphenicol, were considered as contaminants, considering the Yellow River Estuary as the study area. The distribution, sources and ecological risks of typical antibiotics in the Yellow River Estuary were investigated using an optimized solid-phase extraction pre-treatment and an Agilent 6410B tandem triple-quadrupole liquid chromatography-mass spectrometer for antibiotic detection. The results show that antibiotics were widely present in the water bodies of the Yellow River Estuary, with 14 antibiotics detected to varying degrees, including a high detection rate for lincomycin hydrochloride. Farming wastewater and domestic sewage were the primary sources of antibiotics in the Yellow River Estuary. The distribution characteristics of antibiotics in the study area were linked to the development of farming and social activities. The ecological risk evaluation of 14 antibiotics in the Yellow River Estuary watershed showed that clarithromycin and doxycycline hydrochloride were present at medium-risk levels, and lincomycin hydrochloride, sulfamethoxazole, methomyl, oxifloxacin, enrofloxacin, sulfadiazine, roxithromycin, sulfapyridine, sulfadiazine and ciprofloxacin were present at low-risk levels in the samples collected from water bodies of the Yellow River Estuary. This study provides novel, beneficial information for the assessment of the ecological risk presented by antibiotics in the Yellow River Estuary water bodies and provides a scientific basis for future antibiotic pollution control in the Yellow River Basin.
PubMed: 37235215
DOI: 10.3390/toxics11050400 -
International Journal of Molecular... Apr 2023In this study, we considered some pesticides as active substances within formulations for the protection of plant-based food in the Republic of Serbia in silico, because...
In this study, we considered some pesticides as active substances within formulations for the protection of plant-based food in the Republic of Serbia in silico, because these pesticides have not often been investigated in this way previously, and in an analytical way, because there are not very many available fast, cheap, and easy methods for their determination in real agricultural samples. Seven pesticides were detected in selected agricultural products (tomatoes, cucumbers, peppers, and grapes) using the QuEChERS methodology and HPLC-DAD. Standard curves for the investigated pesticides (chlorantraniliprole, methomyl, metalaxyl, thiacloprid, acetamiprid, emamectin benzoate, and cymoxanil) show good linearity, with R values from 0.9785 to 0.9996. The HPLC-DAD method is fast, and these pesticides can be determined in real spiked samples in less than 15 min. We further characterized the pesticides we found in food based on physicochemical properties and molecular descriptors to predict the absorption, distribution, metabolism, elimination, and toxicity (ADMET) of the compounds. We summarized the data supporting their effects on humans using various computational tools to determine their potential adverse effects. The results of our prediction study show that all of the selected pesticides considered in this study have good oral bioavailability, and those with high toxicity, therefore, could be harmful to human health. Chlorantraniliprole was shown in a molecular docking study as a good starting point for a new Alzheimer's disease drug candidate.
Topics: Humans; Pesticides; Chromatography, High Pressure Liquid; Molecular Docking Simulation; ortho-Aminobenzoates; Pesticide Residues
PubMed: 37175728
DOI: 10.3390/ijms24098003 -
Journal of Environmental Science and... 2023Micro-Multiple Reflection ATR (CMRATR) spectroscopy is a technique, using specialized equipment, which allows the enhanced sensitivity of multiple reflection ATR...
Micro-Multiple Reflection ATR (CMRATR) spectroscopy is a technique, using specialized equipment, which allows the enhanced sensitivity of multiple reflection ATR analysis of small amounts of liquids in a confined area hitherto reserved for single reflection equipment. This technique has demonstrated a high level of sensitivity, especially when used in conjunction with an evaporative technique. In this work, the technique will be used with a miniature CMRATR accessory, which has the added advantage of compatibility with the smallest current FTIR spectrometers, to analyze pesticides. The results presented here indicate that the CMRATR/evaporative technique can serve as both qualitative and quantitative support to the existing standard methodology.
Topics: Spectroscopy, Fourier Transform Infrared; Feasibility Studies
PubMed: 37150899
DOI: 10.1080/03601234.2023.2208995 -
Scientific Reports May 2023Insecticides are an integral part of most of the cropping systems worldwide; however, these usually exert negative impact on the environment and non-target insects as...
Insecticides are an integral part of most of the cropping systems worldwide; however, these usually exert negative impact on the environment and non-target insects as well. Non-target insects are prone to develop resistance to insecticides due to prolonged and repeated lethal and sublethal exposures. Musca domestica is a common non-target, pollinator and nectar feeder species in cotton ecosystem, besides its status as a public health pest in human habitations. In the present work, resistance to methomyl, one of the major insecticides used for cotton pest management, was assessed in 20 M. domestica strains from the major cotton producing areas of the Punjab and Sindh provinces of Pakistan. The results revealed that toxicity values of methomyl for Punjabi and Sindhi strains ranged from 28.07 to 136.16 µg fly and 29.32 to 136.87 µg fly, respectively. Among Punjabi strains, D.G. Khan, Lodhran, Bahawalpur, Toba Tek Singh, Bahawalnagar, Rajanpur and Jhang strains exhibited very high levels of resistance (RR > 100) to methomyl; Bhakkar, Kasur, Vehari, Layyah, Muzaffargarh and R.Y. Khan showed high resistance (RR = 51-100 fold), while the Mianwali strain showed a moderate level of resistance to methomyl (RR = 36.45 fold). In case of Sindhi strains, very high levels of resistance (> 100 fold) were reported for Sukkar and Sanghar strains, high levels of resistance (RR 51-100 fold) for Khairpur, Jamshoro and Ghotki, and moderate resistance to methomyl (38.08 fold) in the Dadu strain. There was a significant synergism of methomyl toxicity in all field strains when methomyl bioassayed along with piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) providing clues of metabolic-based mechanisms of resistance to methomyl. In conclusion, insecticides used in crop farming can cause resistance development in non-target M. domestica. It is necessary to adopt the pest management activities that are safe for the environment and non-target insect species.
Topics: Animals; Humans; Insecticides; Methomyl; Houseflies; Pakistan; Ecosystem; Insecticide Resistance
PubMed: 37127684
DOI: 10.1038/s41598-023-34331-4 -
Toxics Apr 2023There is limited literature analyzing the outcome of human poisoning with methomyl and cypermethrin pesticide mixture. Between 2002 and 2018, a total of 63 patients...
There is limited literature analyzing the outcome of human poisoning with methomyl and cypermethrin pesticide mixture. Between 2002 and 2018, a total of 63 patients intoxicated with methomyl, cypermethrin, or their pesticide mixture were treated at Chang Gung Memorial Hospital. The patients were categorized into three groups based on the type of pesticide, as methomyl (n = 10), cypermethrin (n = 31), or methomyl and cypermethrin (n = 22). Demographic, clinical, laboratory, and mortality data were obtained for analysis. The patients were aged 54.9 ± 18.9 years. Following ingestion, the patients experienced a wide range of clinical symptoms, including aspiration pneumonia (50.8%), acute respiratory failure (41.3%), acute kidney injury (33.3%), multiple organ failure (19.0%), emesis (19.0%), acute hepatitis (12.7%), diarrhea (7.9%), seizures (4.8%), lacrimation (4.8%), etc. After analysis, it was found that patients with methomyl and cypermethrin poisoning suffered higher incidences of acute respiratory failure ( < 0.001), aspiration pneumonia ( = 0.004), acute kidney injury ( = 0.011), and multiple organ failure ( < 0.001) than the other groups. Laboratory analyses revealed that patients with methomyl and cypermethrin poisoning had a higher creatinine level ( = 0.011), white blood cell count ( < 0.001), and neutrophil count ( = 0.019) than the other groups. A total of seven (11.1%) patients died. The average duration of hospitalization was 9.8 ± 10.0 days. In a multivariate logistic regression model, it was revealed that methomyl pesticide ( = 0.045) or methomyl and cypermethrin pesticide mixture ( = 0.013) were significant risk factors for acute respiratory failure. Nevertheless, no mortality risk factor could be identified. Therefore, the analytical results suggest that methomyl pesticide is the major contributor to the toxicity of methomyl and cypermethrin pesticide mixture poisoning. More research is needed.
PubMed: 37112599
DOI: 10.3390/toxics11040372 -
Environmental Science and Pollution... May 2023As a typical carbamate pesticide, methomyl was once widely used in agriculture for its excellent broad-spectrum insecticidal effect. However, due to its high toxicity,...
As a typical carbamate pesticide, methomyl was once widely used in agriculture for its excellent broad-spectrum insecticidal effect. However, due to its high toxicity, long half-life, and difficult degradation properties, it poses a serious challenge to water environment pollution. In this study, an electrode-free discharge microwave-induced plasma technology was used to rapidly and efficiently degrade methomyl in aqueous solution. In this experiment, the statistical design of experiments (DOE) was adopted to optimize the plasma degradation parameters. Under the optimized parameters (P = 140 W, D = 0 mm, R = 0.5 L/min), 78.4% removal of 50 mg/L of methomyl was achieved after 8 min. The optical emission spectrometry and free radical detection experiments showed that the active substances generated by the collision reaction between plasma and water molecules occurring at the gas-liquid interface were the key factors to exert the degradation effect. The degradation rate of methomyl decreased by 73.2% after the addition of tert-butanol (OH burster), while it decreased by only about 12.0% after the addition of peroxidase. These implied that ∙OH was largely responsible for methomyl degradation. In addition, based on the detected intermediates, possible degradation mechanisms and pathways were analyzed.
Topics: Methomyl; Microwaves; Insecticides; Pesticides; Water
PubMed: 37067709
DOI: 10.1007/s11356-023-26866-w -
Molecules (Basel, Switzerland) Apr 2023As resistance to the limited number of insecticides available for medical and veterinary pests becomes more widespread, there is an urgent need for new insecticides and...
As resistance to the limited number of insecticides available for medical and veterinary pests becomes more widespread, there is an urgent need for new insecticides and synergists on the market. To address this need, we conducted a study to assess the toxicity of three monoterpenoids-carvone, menthone, and fenchone-in comparison to permethrin and methomyl against adults of two common pests: the yellow fever mosquito () and the house fly (). We also examined the potential for these monoterpenoids to enhance the effectiveness of permethrin and methomyl when used together. Finally, we evaluated the ability of each monoterpenoid to inhibit acetylcholinesterase, comparing them to methomyl. While all three monoterpenoids performed relatively poorly as topical insecticides (LD > 4000 ng/mg on ; >6000 ng/mg on ), they synergized both permethrin and methomyl as well as or better than piperonyl butoxide (PBO). Carvone and menthone yielded synergistic co-toxicity factors (23 and 29, respectively), which were each higher than PBO at 24 h. Currently, the mechanism of action is unknown. During preliminary testing, symptoms of acetylcholinesterase inhibition were identified, prompting further testing. Acetylcholinesterase inhibition did not appear to explain the toxic or synergistic effects of the three monoterpenoids, with IC values greater than 1 mM for all, compared to the 2.5 and 1.7 µM for methomyl on and , respectively. This study provides valuable monoterpenoid toxicity and synergism data on two pestiferous insects and highlights the potential for these chemistries in future pest control formulations.
Topics: Animals; Insecticides; Houseflies; Aedes; Permethrin; Acetylcholinesterase; Methomyl; Muscidae; Monoterpenes; Yellow Fever
PubMed: 37050012
DOI: 10.3390/molecules28073250 -
Journal of Hazardous Materials Jun 2023Methomyl is a widely used carbamate pesticide, which has adverse biological effects and poses a serious threat to ecological environments and human health. Several...
Methomyl is a widely used carbamate pesticide, which has adverse biological effects and poses a serious threat to ecological environments and human health. Several bacterial isolates have been investigated for removing methomyl from environment. However, low degradation efficiency and poor environmental adaptability of pure cultures severely limits their potential for bioremediation of methomyl-contaminated environment. Here, a novel microbial consortium, MF0904, can degrade 100% of 25 mg/L methomyl within 96 h, an efficiency higher than that of any other consortia or pure microbes reported so far. The sequencing analysis revealed that Pandoraea, Stenotrophomonas and Paracoccus were the predominant members of MF0904 in the degradation process, suggesting that these genera might play pivotal roles in methomyl biodegradation. Moreover, five new metabolites including ethanamine, 1,2-dimethyldisulfane, 2-hydroxyacetonitrile, N-hydroxyacetamide, and acetaldehyde were identified using gas chromatography-mass spectrometry, indicating that methomyl could be degraded firstly by hydrolysis of its ester bond, followed by cleavage of the C-S ring and subsequent metabolism. Furthermore, MF0904 can successfully colonize and substantially enhance methomyl degradation in different soils, with complete degradation of 25 mg/L methomyl within 96 and 72 h in sterile and nonsterile soil, respectively. Together, the discovery of microbial consortium MF0904 fills a gap in the synergistic metabolism of methomyl at the community level and provides a potential candidate for bioremediation applications.
Topics: Humans; Methomyl; Biodegradation, Environmental; Pesticides; Bacteria; Soil; Metabolic Networks and Pathways; Microbial Consortia
PubMed: 37003005
DOI: 10.1016/j.jhazmat.2023.131287 -
Toxics Feb 2023(Boisd.) is a prominent agricultural insect pest that has developed resistance to a variety of insecticide classes. In this study, the resistance of three field strains...
BACKGROUND
(Boisd.) is a prominent agricultural insect pest that has developed resistance to a variety of insecticide classes. In this study, the resistance of three field strains of collected over three consecutive seasons (2018 to 2020) from three Egyptian Governorates (El-Fayoum, Behera and Kafr El-Shiekh), to six insecticides was monitored.
METHODS
Laboratory bioassays were carried out using the leaf-dipping method to examine the susceptibility of the laboratory and field strains to the tested insecticides. Activities of detoxification enzymes were determined in an attempt to identify resistance mechanisms.
RESULTS
The results showed that LC values of the field strains ranged from 0.0089 to 132.24 mg/L, and the corresponding resistance ratio (RR) ranged from 0.17 to 4.13-fold compared with the susceptible strain. Notably, low resistance developed to spinosad in all field strains, and very low resistance developed to alpha-cypermethrin and chlorpyrifos. On the other hand, no resistance developed to methomyl, hexaflumeron or . The determination of detoxification enzymes, including carboxylesterases (α- and β-esterase), mixed function oxidase (MFO) and glutathione--transferase (GST), or the target site of acetylcholinesterase (AChE), revealed that the three field strains had significantly different activity levels compared with the susceptible strain.
CONCLUSION
Our findings, along with other tactics, are expected to help with the resistance management of in Egypt.
PubMed: 36976976
DOI: 10.3390/toxics11030211