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Parasites & Vectors Dec 2023Taiwan's warm and humid climate and dense population provide a suitable environment for the breeding of pests. The three major urban insects in Taiwan are house flies,...
BACKGROUND
Taiwan's warm and humid climate and dense population provide a suitable environment for the breeding of pests. The three major urban insects in Taiwan are house flies, cockroaches, and mosquitoes. In cases where a disease outbreak or high pest density necessitates chemical control, selecting the most effective insecticide is crucial. The resistance of pests to the selected environmental insecticide must be rapidly assessed to achieve effective chemical control and reduce environmental pollution.
METHODS
In this study, we evaluated the resistance of various pests, namely, house flies (Musca domestica L.), cockroaches (Blattella germanica L. and Periplaneta americana), and mosquitoes (Aedes aegypti and Ae. albopictus) against 10 commonly used insecticides. Rapid insecticide resistance bioassays were performed using discriminating doses or concentrations of the active ingredients of insecticides.
RESULTS
Five field strains of M. domestica (L.) are resistant to all 10 commonly used insecticides and exhibit cross- and multiple resistance to four types of pyrethroids and three types of organophosphates, propoxur, fipronil, and imidacloprid. None of the five field strains of P. americana are resistant to any of the tested insecticides, and only one strain of B. germanica (L.) is resistant to permethrin. One strain of Ae. albopictus is resistant to pirimiphos-methyl, whereas five strains of Ae. aegypti exhibit multiple resistance to pyrethroids, organophosphates, and other insecticides.
CONCLUSIONS
In the event of a disease outbreak or high pest density, rapid insecticide resistance bioassays may be performed using discriminating doses or concentrations to achieve precise and effective chemical control, reduce environmental pollution, and increase control efficacy.
Topics: Animals; Insecticides; Insecticide Resistance; Taiwan; Pyrethrins; Aedes; Cockroaches; Organophosphates; Biological Assay
PubMed: 38042818
DOI: 10.1186/s13071-023-06055-x -
The Science of the Total Environment Jan 2024Groundwater is an important source for drinking water supply, agricultural irrigation and industrial uses in the Middle East and North Africa region. Due to the growing...
Groundwater is an important source for drinking water supply, agricultural irrigation and industrial uses in the Middle East and North Africa region. Due to the growing need for groundwater use, groundwater quality studies on the presence of contaminants of emerging concern (CECs) and pesticides have gained attention. The Wadi El Bey is one of the most polluted areas in Tunisia. However, very limited data on CECs infiltration into aquifers has been described, in comparison to industrialized countries where groundwater contamination has been comprehensively addressed. To gain early insight into potential contamination, groundwater wells in northeast Tunisia, an area with high population density and intensive agricultural activity were sampled during two seasons and were analyzed with two high resolution mass spectrometry approaches: target and suspect screening. The latter was used for screening banned pesticides. A selection of 116 CECs of which 19 are transformation products (TPs) and 20 pesticides previously prioritized by suspect screening were screened in the groundwater samples. The results showed the presence of 69 CECs and 1 TP and 20 pesticides at concentrations per well, ranging between 43 and 7384 ng L and 7.3 and 80 ng L, respectively. CECs concentrations in Tunisian groundwater do not differ from those in industrialized countries. WWTPs were considered the main source of pollution, where the main classes detected were analgesics, antihypertensives and artificial sweeteners and especially caffeine, salicylic acid and ibuprofen were found to be ubiquitous. Regarding pesticides, triazines herbicides and carbamates insecticides pose the highest concern due to their ubiquitous presence, high leachability potential for most of them and high toxicity. The environmental risk assessment (ERA) highlighted the high risk that caffeine, ibuprofen, and propoxur may pose to the environment, and consequently, to non-target organisms. This study provides occurrence and ERA analysis of CECs and pesticides in Tunisian groundwater.
Topics: Pesticides; Caffeine; Ibuprofen; Water Pollutants, Chemical; Environmental Monitoring; Groundwater; Risk Assessment; Tunisia
PubMed: 37742978
DOI: 10.1016/j.scitotenv.2023.167319 -
Journal of Ethnopharmacology Jun 2023Dendrobium huoshanense C. Z. Tang et S. J. Cheng is an important edible medicinal plant that thickens the stomach and intestines, and its active ingredient,...
Mass spectrometry-based metabolomics reveal Dendrobium huoshanense polysaccharide effects and potential mechanism of N-methyl-N'-nitro-N-nitrosoguanidine -induced damage in GES-1 cells.
ETHNOPHARMACOLOGICAL RELEVANCE
Dendrobium huoshanense C. Z. Tang et S. J. Cheng is an important edible medicinal plant that thickens the stomach and intestines, and its active ingredient, polysaccharide, can have anti-inflammatory, immunoregulatory, and antitumor effects. However, the gastroprotective effects and potential mechanisms of Dendrobium huoshanense polysaccharides (DHP) remain unclear.
AIM OF THE STUDY
An N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) induced human gastric mucosal epithelial cells (GES-1) damage model was used in this research, aiming to investigate whether DHP has a protective effect on MNNG-induced GES-1 cell injury and its underlying mechanism based on the combination of multiple methods.
MATERIALS AND METHODS
DHP was extracted using water extraction and alcohol precipitation methods, and the proteins were removed using the Sevag method. The morphology was observed using scanning electron microscopy. A MNNG-induced GES-1 cell damage model was developed. Cell viability and proliferation of the experimental cells were investigated using a cell counting kit-8 (CCK-8). Cell nuclear morphology was detected using the fluorescent dye Hoechst 33342. Cell scratch wounds and migration were detected using a Transwell chamber. The expression levels of apoptosis proteins (Bcl-2, Bax, Caspase-3) in the experimental cells were detected by Western blotting. Ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was performed to investigate the potential mechanism of action of DHP.
RESULTS
The CCK-8 kit analysis showed that DHP increased GES-1 cell viability and ameliorated GES-1 cell injury by MNNG. In addition, scratch assay and Transwell chambers results suggested that DHP improved the MNNG-induced motility and migration ability of GES-1 cells. Likewise, the results of the apoptotic protein assay indicated that DHP had a protective effect against gastric mucosal epithelial cell injury. To further investigate the potential mechanism of action of DHP, we analyzed the metabolite differences between GES-1 cells, GES-1 cells with MNNG-induced injury, and DHP + MMNG-treated cells using UHPLC-HRMS. The results indicated that DHP upregulated 1-methylnicotinamide, famotidine, N4-acetylsulfamethoxazole, acetyl-L-carnitine, choline and cer (d18:1/19:0) metabolites and significantly down-regulated 6-O-desmethyldonepezil, valet hamate, L-cystine, propoxur, and oleic acid.
CONCLUSIONS
DHP may protect against gastric mucosal cell injury through nicotinamide and energy metabolism-related pathways. This research may provide a useful reference for further in-depth studies on the treatment of gastric cancer, precancerous lesions, and other gastric diseases.
Topics: Humans; Methylnitronitrosoguanidine; Dendrobium; Stomach Neoplasms; Polysaccharides; Mass Spectrometry
PubMed: 36889419
DOI: 10.1016/j.jep.2023.116342 -
Malaria Journal Jul 2023Malaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of invasive Anopheles stephensi, capable...
BACKGROUND
Malaria, transmitted by the bite of infective female Anopheles mosquitoes, remains a global public health problem. The presence of invasive Anopheles stephensi, capable of transmitting Plasmodium vivax and Plasmodium falciparum, was first reported in Ethiopia in 2016. The ecology of this mosquito species differs from that of Anopheles arabiensis, the primary malaria vector in Ethiopia. This study aimed to evaluate the efficacy of selected insecticides, which are used in indoor residual spraying (IRS) and selected long-lasting insecticidal nets (LLINs) for malaria vector control against adult An. stephensi.
METHODS
Anopheles stephensi mosquitoes were collected as larvae and pupae from Awash Subah Kilo Town and Haro Adi village, Ethiopia. Adult female An. stephensi, reared from larvae and pupae collected from the field, aged 3-5 days were exposed to impregnated papers of IRS insecticides (propoxur 0.1%, bendiocarb 0.1%, pirimiphos-methyl 0.25%), and insecticides used in LLINs (alpha-cypermethrin 0.05%, deltamethrin 0.05% and permethrin 0.75%), using diagnostic doses and WHO test tubes in a bio-secure insectary at Aklilu Lemma Institute of Pathobiology, Addis Ababa University. For each test and control tube, batches of 25 female An. stephensi were used to test each insecticide used in IRS. Additionally, cone bioassay tests were conducted to expose An. stephensi from the reared population to four brands of LLINs, MAGNet™ (alpha-cypermethrin), PermaNet 2.0 (deltamethrin), DuraNet (alpha-cypermethrin) and SafeNet (alpha-cypermethrin). A batch of ten sugar-fed female mosquitoes aged 2-5 days was exposed to samples taken from five positions/sides of a net. The data from all replicates were pooled and descriptive statistics were used to describe features of the data.
RESULTS
All An. stephensi collected from Awash Subah Kilo Town and Haro Adi village (around Metehara) were resistant to all tested insecticides used in both IRS and LLINs. Of the tested LLINs, only MAGNet™ (alpha-cypermethrin active ingredient) caused 100% knockdown and mortality to An. stephensi at 60 min and 24 h post exposure, while all other net brands caused mortality below the WHO cut-off points (< 90%). All these nets, except SafeNet, were collected during LLIN distribution for community members through the National Malaria Programme, in December 2020.
CONCLUSIONS
Anopheles stephensi is resistant to all tested insecticides used in IRS and in the tested LLIN brands did not cause mosquito mortality as expected, except MAGNet. This suggests that control of this invasive vector using existing adult malaria vector control methods will likely be inadequate and that alternative strategies may be necessary.
Topics: Humans; Adult; Animals; Female; Insecticides; Anopheles; Ethiopia; Mosquito Control; Mosquito Vectors; Malaria; Insecticide-Treated Bednets; Pyrethrins; Insecticide Resistance
PubMed: 37501142
DOI: 10.1186/s12936-023-04649-5 -
Toxics Sep 2023The evidence linking the use of household pesticides and the risk of lymphoma is scanty.
BACKGROUND
The evidence linking the use of household pesticides and the risk of lymphoma is scanty.
METHODS
We explored the hypothesis in a population-based case-control study on lymphoma conducted in Sardinia, Italy, in 1998-2004, including 325 cases and 465 population controls and data on lifetime frequency, seasonality, and years of use of household insecticides and potential confounders. We calculated the risk of lymphoma (all subtypes) and its major subtypes associated with using household insecticides in three time windows (up to 1978, from 1979-2001, and 2002 onwards) with unconditional logistic regression adjusting by age, sex, education, and occupational exposure to pesticides.
RESULTS
Household insecticides did not increase risk of lymphoma (all subtypes), Hodgkin's lymphoma, B-cell lymphoma, and the major B-cell lymphoma subtypes. The risk of multiple myeloma (MM) but not the other subtypes showed a non-significant upward trend ( = 0.203) with increasing quartiles of days of use in the time window when propoxur was the most popular household insecticide.
CONCLUSIONS
Our results suggest no association between the household use of insecticides and the risk of lymphoma. Further studies are warranted to confirm or discard an association between MM risk and the use of propoxur.
PubMed: 37755762
DOI: 10.3390/toxics11090752 -
Revista Argentina de Microbiologia 2024The application of pyrethroids and carbamates represents an environmental risk and may exert adverse effects on beneficial microorganisms such as Trichoderma, which...
The application of pyrethroids and carbamates represents an environmental risk and may exert adverse effects on beneficial microorganisms such as Trichoderma, which contribute to the biocontrol of several fungal phytopathogens. This research evaluated the tolerance of several strains of Trichoderma to a selected culture medium contaminated with a commercial insecticide (H24®) composed of pyrethroids, permethrin and prallethrin, and carbamate propoxur, and determined the influence of this insecticide on the release of enzymes such as chitinases, peroxidases, and endoglucanases by a consortium of selected Trichoderma strains grown in liquid culture medium. Four out of 10 Trichoderma strains showed tolerance to 200ppm (∼48.3% of growth) of the commercial insecticide after 96h of exposure to a contaminated solid medium. After eight days of growth in liquid culture, the insecticide enhanced extracellular protein content and peroxidase activities in the Trichoderma consortium but decreased both chitinase and glucanase activities. These fungal responses should be considered when implementing strategies that combine alternative pesticides and fungal biocontrollers for managing fungal phytopathogens.
Topics: Trichoderma; Insecticides; Pyrethrins; Chitinases; Carbamates; Culture Media
PubMed: 37640657
DOI: 10.1016/j.ram.2023.06.004 -
Journal of the American Mosquito... Mar 2024The Asian tiger mosquito, Aedes albopictus, is an important vector of chikungunya, dengue, yellow fever, and Zika viruses. Vector control remains an important means for...
The Asian tiger mosquito, Aedes albopictus, is an important vector of chikungunya, dengue, yellow fever, and Zika viruses. Vector control remains an important means for the prevention and control of vector-borne diseases. The development of insecticide resistance has become a serious threat to the efficacy of insecticide-based control programs. To understand the resistance status and the underlying genetic mechanism in mosquitoes in Guangyuan City of Sichuan Province, China, we investigated the susceptibility of Ae. albopictus to four commonly used insecticides. We found that all the examined populations were susceptible to malathion and propoxur. However, Ae. albopictus populations in Guangyuan showed a possible resistance to the two tested pyrethroids (beta-cypermethrin and deltamethrin). Notably, phenotypic resistance to deltamethrin was detected in 2 of the 7 populations. The potential of resistance to pyrethroids was confirmed by the presence of knockdown resistance (kdr) related mutations in the voltage-gated sodium channel. Four kdr mutations (V1016G, I1532T, F1534L, and F1534S) were identified to be present alone or in combination, and their distribution displayed significant spatial heterogeneity. These findings are helpful for making evidence-based mosquito control strategies and highlight the need to regularly monitor the dynamics of pyrethroid resistance in this city.
Topics: Animals; Insecticides; Mosquito Vectors; Pyrethrins; Mutation; China; Zika Virus; Zika Virus Infection; Aedes; Nitriles
PubMed: 38243835
DOI: 10.2987/23-7155 -
Journal of Dairy Science Apr 2024This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw...
Detection of 11 carbamate pesticide residues in raw and pasteurized camel milk samples using liquid chromatography tandem mass spectrometry: Method development, method validation, and health risk assessment.
This study aimed to use ultra-high-performance liquid chromatography coupled to a triple-quadrupole mass spectrometer to detect 11 carbamate pesticide residues in raw and pasteurized camel milk samples collected from the United Arab Emirates. A method was developed and validated by evaluating limits of detection, limits of quantitation, linearity, extraction recovery, repeatability, intermediate precision, and matrix effect. Due to the high protein and fat content in camel milk, a sample preparation step was necessary to avoid potential interference during analysis. For this purpose, 5 different liquid-liquid extraction techniques were evaluated to determine their efficiency in extracting carbamate pesticides from camel milk. The established method demonstrated high accuracy and precision. The matrix effect for all carbamate pesticides was observed to fall within the soft range, indicating its negligible effect. Remarkably, detection limits for all carbamates were as low as 0.01 μg/kg. Additionally, the coefficients of determination were >0.998, demonstrating excellent linearity. A total of 17 camel milk samples were analyzed, and only one sample was found to be free from any carbamate residues. The remaining 16 samples contained at least one carbamate residue, yet all detected concentrations were below the recommended maximum residue limits set by Codex Alimentarius and the European Union pesticide databases. Nonetheless, it is worth noting that the detected levels of ethiofencarb in 3 samples were close to the borderline of the maximum residue limit. To assess the health risk for consumers of camel milk, the hazard index values of carbofuran, carbaryl, and propoxur were calculated. The hazard index values for these 3 carbamate pesticides were all below 1, indicating that camel milk consumers are not at risk from these residues.
Topics: Animals; Pesticide Residues; Tandem Mass Spectrometry; Camelus; Milk; Chromatography, Liquid; Chromatography, High Pressure Liquid; Carbamates; Risk Assessment
PubMed: 37923201
DOI: 10.3168/jds.2023-23512 -
PLoS Neglected Tropical Diseases Feb 2024Insecticide resistance is a serious threat to our ability to control mosquito vectors which transmit pathogens including malaria parasites and arboviruses. Understanding...
Insecticide resistance is a serious threat to our ability to control mosquito vectors which transmit pathogens including malaria parasites and arboviruses. Understanding the underlying mechanisms is an essential first step in tackling the challenges presented by resistance. This study aimed to functionally characterise the carboxylesterase, CCEae3A, the elevated expression of which has been implicated in temephos resistance in Aedes aegypti and Aedes albopictus larvae. Using our GAL4/UAS expression system, already established in insecticide-sensitive Anopheles gambiae mosquitoes, we produced transgenic An. gambiae mosquitoes that express an Ae. aegypti CCEae3A ubiquitously. This new transgenic line permits examination of CCEae3A expression in a background in which there is not a clear orthologue in Vectorbase and allows comparison with existing An. gambiae GAL4-UAS lines. Insecticide resistance profiling of these transgenic An. gambiae larvae indicated significant increases in resistance ratio for three organophosphate insecticides, temephos (6), chloropyriphos (6.6) and fenthion (3.2) when compared to the parental strain. Cross resistance to adulticides from three major insecticide classes: organophosphates (malathion, fenitrothion and pirimiphos methyl), carbamates (bendiocarb and propoxur) and pyrethroid (alpha-cypermethrin) was also detected. Resistance to certain organophosphates and carbamates validates conclusions drawn from previous expression and phenotypic data. However, detection of resistance to pirimiphos methyl and alphacypermethrin has not previously been formally associated with CCEae3A, despite occurring in Ae. aegypti strains where this gene was upregulated. Our findings highlight the importance of characterising individual resistance mechanisms, thereby ensuring accurate information is used to guide future vector control strategies.
Topics: Animals; Aedes; Carbamates; Insecticides; Organophosphates; Temefos; Animals, Genetically Modified; Pyrethrins; Organothiophosphorus Compounds
PubMed: 38377131
DOI: 10.1371/journal.pntd.0011595