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BMC Infectious Diseases May 2024The use of temephos, the most common intervention for the chemical control of Aedes aegypti over the last half century, has disappointing results in control of the... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The use of temephos, the most common intervention for the chemical control of Aedes aegypti over the last half century, has disappointing results in control of the infection. The footprint of Aedes and the diseases it carries have spread relentlessly despite massive volumes of temephos. Recent advances in community participation show this might be more effective and sustainable for the control of the dengue vector.
METHODS
Using data from the Camino Verde cluster randomized controlled trial, a compartmental mathematical model examines the dynamics of dengue infection with different levels of community participation, taking account of gender of respondent and exposure to temephos.
RESULTS
Simulation of dengue endemicity showed community participation affected the basic reproductive number of infected people. The greatest short-term effect, in terms of people infected with the virus, was the combination of temephos intervention and community participation. There was no evidence of a protective effect of temephos 220 days after the onset of the spread of dengue.
CONCLUSIONS
Male responses about community participation did not significantly affect modelled numbers of infected people and infectious mosquitoes. Our model suggests that, in the long term, community participation alone may have the best results. Adding temephos to community participation does not improve the effect of community participation alone.
Topics: Dengue; Humans; Male; Temefos; Female; Insecticides; Community Participation; Animals; Aedes; Adult; Models, Theoretical; Sex Factors; Young Adult; Adolescent; Mosquito Control; Middle Aged
PubMed: 38698345
DOI: 10.1186/s12879-024-09341-w -
Ecotoxicology and Environmental Safety Jun 2024Environmental exposure to endocrine disruptors, such as pesticides, could contribute to a decline of human fertility. Glyphosate (GLY) is the main component of...
Environmental exposure to endocrine disruptors, such as pesticides, could contribute to a decline of human fertility. Glyphosate (GLY) is the main component of Glyphosate Based Herbicides (GBHs), which are the most commonly herbicides used in the world. Various animal model studies demonstrated its reprotoxicity. In Europe, GLY authorization in agriculture has been extended until 2034. Meanwhile the toxicity of GLY in humans is still in debate. The aims of our study were firstly to analyse the concentration of GLY and its main metabolite, amino-methyl-phosphonic acid (AMPA) by LC/MS-MS in the seminal and blood plasma in an infertile French men population (n=128). We secondly determined Total Antioxidant Status (TAS) and Total Oxidant Status (TOS) using commercial colorimetric kits and some oxidative stress biomarkers including malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) by ELISA assays. We next analysed potential correlations between GLY and oxidative stress biomarkers concentration and sperm parameters (sperm concentration, progressive speed, anormal forms). Here, we detected for the first time GLY in the human seminal plasma in significant proportions and we showed that its concentration was four times higher than those observed in blood plasma. At the opposite, AMPA was undetectable. We also observed a strong positive correlation between plasma blood GLY concentrations and plasma seminal GLY and 8-OHdG concentrations, the latter reflecting DNA impact. In addition, TOS, Oxidative Stress Index (OSI) (TOS/TAS), MDA blood and seminal plasma concentrations were significantly higher in men with glyphosate in blood and seminal plasma, respectively. Taken together, our results suggest a negative impact of GLY on the human reproductive health and possibly on his progeny. A precaution principle should be applied at the time of the actual discussion of GLY and GBHs formulants uses in Europe by the authorities.
Topics: Humans; Male; Glyphosate; Glycine; Oxidative Stress; France; Adult; Herbicides; Spermatozoa; Infertility, Male; Semen; Biomarkers; Malondialdehyde; Organophosphonates; Middle Aged
PubMed: 38696871
DOI: 10.1016/j.ecoenv.2024.116410 -
Malaria Journal Apr 2024The decreasing residual efficacy of insecticides is an important factor when making decisions on insecticide choice for national malaria control programmes. The major...
BACKGROUND
The decreasing residual efficacy of insecticides is an important factor when making decisions on insecticide choice for national malaria control programmes. The major challenge to using chemicals for vector control is the selection for the development of insecticide resistance. Since insecticide resistance has been recorded for most of the existing insecticides used for indoor residual spraying, namely, DDT, pyrethroids, organophosphates and carbamates, and new chemicals are necessary for the continued success of indoor residual spraying. The aim of this study was to assess the residual efficacy of Actellic 300CS, SumiShield™ 50WG and Fludora®Fusion by spraying on different wall surfaces.
METHODS
One hundred and sixty-eight houses with different wall surface types (mud, cement, painted cement, and tin) which represented the rural house wall surface types in KwaZulu-Natal, South Africa were used to evaluate the residual efficacy of Actellic 300CS, SumiShield 50WG and Fludora®Fusion with DDT as the positive control. All houses were sprayed by experienced spray operators from the Malaria Control Programme. Efficacy of these insecticides were evaluated by contact bioassays against Anopheles arabiensis, a vector species. The residual efficacy of the insecticide formulations was evaluated against a susceptible insectary-reared population of An. arabiensis using WHO cone bioassays.
RESULTS
Effectiveness of the three insecticides was observed up to 12 months post-spray. When assessing the achievement of 100% mortality over time, SumiShield performed significantly better than DDT on mud (OR 2.28, 95% CI 1.72-3.04) and painted cement wall types (OR 3.52, 95% CI 2.36-5.26). On cement wall types, Actellic was found to be less effective than DDT (OR 0.55, 95% CI 0.37-0.82) while Fludora®Fusion was less effective on tin wall types (OR 0.67, 95% CI 0.47-0.95). When compared to the combined efficacy of DDT on mud surfaces, SumiShield applied to each of the mud, cement and painted cement wall types and DDT applied to the cement wall types was found to be significantly more effective. These insecticides usually resulted in 100% mortality for up to 12 months with a delayed mortality period of 96-144 h, depending on the insecticide evaluated and the surface type sprayed.
CONCLUSION
Field evaluation of these insecticides have shown that Actellic, SumiShield and Fludora®Fusion are suitable replacements for DDT. Each of these insecticides can be used for malaria vector control, requiring just one spray round. These insecticides can be used in rotation or as mosaic spraying.
Topics: Insecticides; Anopheles; Animals; Mosquito Control; South Africa; Housing; Malaria; Humans; Biological Assay; Mosquito Vectors; Insecticide Resistance
PubMed: 38689283
DOI: 10.1186/s12936-024-04963-6 -
Journal of Hazardous Materials Jun 2024Parallel to the important use of pesticides in conventional agriculture there is a growing interest for green technologies to clear contaminated soil from pesticides and...
Parallel to the important use of pesticides in conventional agriculture there is a growing interest for green technologies to clear contaminated soil from pesticides and their degradation products. Bioaugmentation i. e. the inoculation of degrading micro-organisms in polluted soil, is a promising method still in needs of further developments. Specifically, improvements in the understanding of how degrading microorganisms must overcome abiotic filters and interact with the autochthonous microbial communities are needed in order to efficiently design bioremediation strategies. Here we designed a protocol aiming at studying the degradation of two herbicides, glyphosate (GLY) and isoproturon (IPU), via experimental modifications of two source bacterial communities. We used statistical methods stemming from genomic prediction to link community composition to herbicides degradation potentials. Our approach proved to be efficient with correlation estimates over 0.8 - between model predictions and measured pesticide degradation values. Multi-degrading bacterial communities were obtained by coalescing bacterial communities with high GLY or IPU degradation ability based on their community-level properties. Finally, we evaluated the efficiency of constructed multi-degrading communities to remove pesticide contamination in a different soil. While results are less clear in the case of GLY, we showed an efficient transfer of degrading capacities towards the receiving soil even at relatively low inoculation levels in the case of IPU. Altogether, we developed an innovative protocol for building multi-degrading simplified bacterial communities with the help of genomic prediction tools and coalescence, and proved their efficiency in a contaminated soil.
Topics: Biodegradation, Environmental; Soil Pollutants; Soil Microbiology; Glyphosate; Glycine; Bacteria; Herbicides; Phenylurea Compounds; Pesticide Residues
PubMed: 38688223
DOI: 10.1016/j.jhazmat.2024.134454 -
Pesticide Biochemistry and Physiology May 2024White mustard, (Sinapis alba), a problematic broadleaf weed in many Mediterranean countries in arable fields has been detected as resistant to tribenuron-methyl in...
White mustard, (Sinapis alba), a problematic broadleaf weed in many Mediterranean countries in arable fields has been detected as resistant to tribenuron-methyl in Tunisia. Greenhouse and laboratory studies were conducted to characterize Target-Site Resistance (TSR) and the Non-Target Site Resistance (NTSR) mechanisms in two suspected white mustard biotypes. Herbicide dose-response experiments confirmed that the two S. alba biotypes were resistant to four dissimilar acetolactate synthase (ALS)-pinhibiting herbicide chemistries indicating the presence of cross-resistance mechanisms. The highest resistance factor (>144) was attributed to tribenuron-methyl herbicide and both R populations survived up to 64-fold the recommended field dose (18.7 g ai ha). In this study, the metabolism experiments with malathion (a cytochrome P450 inhibitor) showed that malathion reduced resistance to tribenuron-methyl and imazamox in both populations, indicating that P450 may be involved in the resistance. Sequence analysis of the ALS gene detected target site mutations in the two R biotypes, with amino acid substitutions Trp574Leu, the first report for the species, and Pro197Ser. Molecular docking analysis showed that ALS enzyme cannot properly bind to tribenuron-methyl's aromatic ring due to a reduction in the number of hydrogen bonds, while imazamox can still bind. However, Trp574Leu can weaken the binding affinity between the mutated ALS enzyme and both herbicides with the loss of crucial interactions. This investigation provides substantial evidence for the risk of evolving multiple resistance in S. alba to auxin herbicides while deciphering the TSR and NTSR mechanisms conferring cross resistance to ALS inhibitors.
Topics: Acetolactate Synthase; Herbicides; Herbicide Resistance; Sinapis; Malathion; Mutation; Plant Proteins; Arylsulfonates; Molecular Docking Simulation; Imidazoles
PubMed: 38685248
DOI: 10.1016/j.pestbp.2024.105882 -
PLoS Biology Apr 2024Peptidoglycan (PG) and most surface glycopolymers and their modifications are built in the cytoplasm on the lipid carrier undecaprenyl phosphate (UndP). These...
Peptidoglycan (PG) and most surface glycopolymers and their modifications are built in the cytoplasm on the lipid carrier undecaprenyl phosphate (UndP). These lipid-linked precursors are then flipped across the membrane and polymerized or directly transferred to surface polymers, lipids, or proteins. Despite its essential role in envelope biogenesis, UndP is maintained at low levels in the cytoplasmic membrane. The mechanisms by which bacteria distribute this limited resource among competing pathways is currently unknown. Here, we report that the Bacillus subtilis transcription factor SigM and its membrane-anchored anti-sigma factor respond to UndP levels and prioritize its use for the synthesis of the only essential surface polymer, the cell wall. Antibiotics that target virtually every step in PG synthesis activate SigM-directed gene expression, confounding identification of the signal and the logic of this stress-response pathway. Through systematic analyses, we discovered 2 distinct responses to these antibiotics. Drugs that trap UndP, UndP-linked intermediates, or precursors trigger SigM release from the membrane in <2 min, rapidly activating transcription. By contrasts, antibiotics that inhibited cell wall synthesis without directly affecting UndP induce SigM more slowly. We show that activation in the latter case can be explained by the accumulation of UndP-linked wall teichoic acid precursors that cannot be transferred to the PG due to the block in its synthesis. Furthermore, we report that reduction in UndP synthesis rapidly induces SigM, while increasing UndP production can dampen the SigM response. Finally, we show that SigM becomes essential for viability when the availability of UndP is restricted. Altogether, our data support a model in which the SigM pathway functions to homeostatically control UndP usage. When UndP levels are sufficiently high, the anti-sigma factor complex holds SigM inactive. When levels of UndP are reduced, SigM activates genes that increase flux through the PG synthesis pathway, boost UndP recycling, and liberate the lipid carrier from nonessential surface polymer pathways. Analogous homeostatic pathways that prioritize UndP usage are likely to be common in bacteria.
Topics: Cell Wall; Bacillus subtilis; Signal Transduction; Bacterial Proteins; Peptidoglycan; Polyisoprenyl Phosphates; Anti-Bacterial Agents; Gene Expression Regulation, Bacterial; Cell Membrane
PubMed: 38683856
DOI: 10.1371/journal.pbio.3002589 -
Spectrochimica Acta. Part A, Molecular... Aug 2024For addressing the challenges of strong affinity SERS substrate to organophosphorus pesticides (OPs), herein, a rapid water-assisted layer-by-layer heteronuclear growth...
For addressing the challenges of strong affinity SERS substrate to organophosphorus pesticides (OPs), herein, a rapid water-assisted layer-by-layer heteronuclear growth method was investigated to grow uniform UiO-66 shell with controllable thickness outside the magnetic core and provide abundant defect sites for OPs adsorption. By further assembling the tailored Au@Ag, a highly sensitive SERS substrate FeO-COOH@UiO-66/Au@Ag (FCUAA) was synthesized with a SERS enhancement factor of 2.11 × 10. The substrate's suitability for the actual vegetable samples (cowpeas and peppers) was confirmed under both destructive and non-destructive detection conditions, showing a strong SERS response to fenthion and triazophos, with limits of detection of 1.21 × 10 and 2.96 × 10 mg/kg in the vegetables under destructive conditions, and 0.13 and 1.39 ng/cm for non-destructive detection, respectively. The FCUAA substrate had high SERS performance, effective adsorption capability for OPs, and demonstrated good applicability, thus exhibiting great potential for rapid detection of trace OPs residues in the food industry.
Topics: Spectrum Analysis, Raman; Pesticide Residues; Vegetables; Gold; Organophosphorus Compounds; Silver; Fenthion; Triazoles; Limit of Detection; Organothiophosphates; Food Contamination; Adsorption
PubMed: 38678838
DOI: 10.1016/j.saa.2024.124336 -
Ecotoxicology and Environmental Safety Jun 2024Farmland soil organisms frequently encounter pesticide mixtures presented in their living environment. However, the underlying toxic mechanisms employed by soil animals...
Farmland soil organisms frequently encounter pesticide mixtures presented in their living environment. However, the underlying toxic mechanisms employed by soil animals to cope with such combined pollution have yet to be explored. This investigation aimed to reveal the changes in cellular and mRNA levels under chlorpyrifos (CPF) and lambda-cyhalothrin (LCT) co-exposures in earthworms (Eisenia fetida). Results exhibited that the combination of CPF and LCT triggered an acute synergistic influence on the animals. Most exposures resulted in significant alterations in the activities of total superoxide dismutase (T-SOD), copper/zinc superoxide dismutase (Cu/Zn-SOD), caspase 3, and carboxylesterase (CarE) compared to the basal level. Moreover, when exposed to chemical mixtures, the transcription levels of four genes [heat shock protein 70 (hsp70), gst, sod, and calreticulin (crt)] also displayed more pronounced changes compared with their individual exposures. These changes in determined parameters indicated the occurrence of oxidative stress, cell death, detoxification dysfunction, and endoplasmic reticulum damage after co-exposure to CPF and LCT in E. fetida. The comprehensive examination of mixture toxicities of CPF and LCT at different endpoints would help to understand the overall toxicity they cause to soil invertebrates. The augmented deleterious effect of these pesticides in a mixture suggested that mixture toxicity assessment was necessary for the safety evaluation and application of pesticide mixtures.
Topics: Animals; Oligochaeta; Chlorpyrifos; Pyrethrins; Nitriles; Superoxide Dismutase; Soil Pollutants; Oxidative Stress; HSP70 Heat-Shock Proteins; Carboxylesterase; Insecticides; Caspase 3; Calreticulin; Glutathione Transferase
PubMed: 38677072
DOI: 10.1016/j.ecoenv.2024.116374 -
International Journal of Molecular... Apr 2024The trichothecene biosynthesis in begins with the cyclization of farnesyl pyrophosphate to trichodiene, followed by subsequent oxygenation to isotrichotriol. This...
The trichothecene biosynthesis in begins with the cyclization of farnesyl pyrophosphate to trichodiene, followed by subsequent oxygenation to isotrichotriol. This initial bicyclic intermediate is further cyclized to isotrichodermol (ITDmol), a tricyclic precursor with a toxic trichothecene skeleton. Although the first cyclization and subsequent oxygenation are catalyzed by enzymes encoded by and , the second cyclization occurs non-enzymatically. Following ITDmol formation, the enzymes encoded by , , , and catalyze 3--acetylation, 15-hydroxylation, 15--acetylation, and A-ring oxygenation, respectively. In this study, we extensively analyzed the metabolites of the corresponding pathway-blocked mutants of . The disruption of these genes, except , led to the accumulation of tricyclic trichothecenes as the main products: ITDmol due to disruption; a mixture of isotrichodermin (ITD), 7-hydroxyisotrichodermin (7-HIT), and 8-hydroxyisotrichodermin (8-HIT) due to disruption; and a mixture of calonectrin and 3-deacetylcalonectrin due to disruption. However, the Δ mutant accumulated substantial amounts of bicyclic metabolites, isotrichotriol and trichotriol, in addition to tricyclic 15-deacetylcalonectrin (15-deCAL). The ΔΔ double gene disruptant transformed ITD into 7-HIT, 8-HIT, and 15-deCAL. The deletion of and overexpression of and trichothecene regulatory genes did not result in the accumulation of 15-deCAL in the transgenic strain. Thus, the absence of Tri3p and/or the presence of a small amount of 15-deCAL adversely affected the non-enzymatic second cyclization and C-15 hydroxylation steps.
Topics: Fusarium; Cyclization; Trichothecenes; Acetylation; Fungal Proteins; Polyisoprenyl Phosphates; Biosynthetic Pathways
PubMed: 38673874
DOI: 10.3390/ijms25084288 -
International Journal of Molecular... Apr 2024A widely used organophosphate flame retardant (OPFR), triphenyl phosphate (TPP), is frequently detected in various environmental media and humans. However, there is...
A widely used organophosphate flame retardant (OPFR), triphenyl phosphate (TPP), is frequently detected in various environmental media and humans. However, there is little known on the human corneal epithelium of health risk when exposed to TPP. In this study, human normal corneal epithelial cells (HCECs) were used to investigate the cell viability, morphology, apoptosis, and mitochondrial membrane potential after they were exposed to TPP, as well as their underlying molecular mechanisms. We found that TPP decreased cell viability in a concentration-dependent manner, with a half maximal inhibitory concentration (IC50) of 220 μM. Furthermore, TPP significantly induced HCEC apoptosis, decreased mitochondrial membrane potential in a dose-dependent manner, and changed the mRNA levels of the apoptosis biomarker genes (, , , , and ). The results showed that TPP induced cytotoxicity in HCECs, eventually leading to apoptosis and changes in mitochondrial membrane potential. In addition, the caspase-dependent mitochondrial pathways may be involved in TPP-induced HCEC apoptosis. This study provides a reference for the human corneal toxicity of TPP, indicating that the risks of OPFR to human health cannot be ignored.
Topics: Humans; Apoptosis; Flame Retardants; Mitochondria; Epithelium, Corneal; Membrane Potential, Mitochondrial; Cell Survival; Caspases; Epithelial Cells; Organophosphates; Cells, Cultured
PubMed: 38673741
DOI: 10.3390/ijms25084155