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Frontiers in Chemistry 2019Organophosphorus (OP) pesticides are widely used to control pests because of their high activity. This study described a rapid and sensitive lateral flow...
Organophosphorus (OP) pesticides are widely used to control pests because of their high activity. This study described a rapid and sensitive lateral flow immunochromatographic (LFIC) assay based on up-converting nanoparticles (UCNPs) for multi-residue detection of three OP pesticides. The developed assay integrated novel fluorescent material UCNPs labeled with a broad-specific monoclonal antibody. Based on the competitive platform by immobilized antigen in the test zone, the optimized UCNPs-LFIC assay enabled sensitive detection for parathion, parathion-methyl, and fenitrothion with IC of 3.44, 3.98, and 12.49 ng/mL ( ≥ 0.9776) within 40 min. The detectable ability ranged from 0.98 to 250 ng/mL. There was no cross-reactivity with fenthion, phoxim, isocarbophos, chlorpyrifos, or triazophos, even at a high concentration of 500 ng/mL. Matrix interference from various agricultural products was also studied in food sample detection. In the spiked test, recoveries of the three OP pesticides ranged from 67 to 120% and relative standard deviations were below 19.54%. These results indicated that the proposed strip assay can be an alternative screening tool for rapid detection of the three OP pesticides in food samples.
PubMed: 30792975
DOI: 10.3389/fchem.2019.00018 -
Acta Veterinaria Scandinavica Sep 2018Fleas (Ceratophyllus sciurorum) are common on farmed mink in Denmark. When present, the fleas have a negative impact on the health of the farmed mink and are of nuisance...
BACKGROUND
Fleas (Ceratophyllus sciurorum) are common on farmed mink in Denmark. When present, the fleas have a negative impact on the health of the farmed mink and are of nuisance for farm staff. Severe infestations of fleas cause anemia, poor growth and may result in death of mink kits. Changed behavior of the dams is also observed. Further it has been demonstrated that the fleas are vectors of Aleutian disease virus. Flea control is based on use of a few insecticides and resistance has been reported against permethrin. There is thus a need for new flea control products. In this blinded, randomized clinical trial according to GCP standard, phoxim spray and bendiocarb powder for flea control on mink farms were investigated.
RESULTS
Both the phoxim spray solution and bendiocarb powder were found to be efficient for the control of C. sciurorum fleas on farmed mink. Phoxim treatments reduced the number of fleas by 98.4% and the bendiocarb treatments reduced the number of fleas by 99.0% in the mink nest boxes when compared to counts in controls. No clinical signs were observed post treatment.
CONCLUSIONS
The study demonstrated that phoxim sprayed on the animals and the use of bendiocarb powder in the nest box material were highly efficient for the control of the C. sciurorum fleas on farmed mink. Both products were safe to use at the recommended dose rate. Both compounds are recommended to be integrated in a new farm management plan suggested here.
Topics: Animals; Denmark; Flea Infestations; Mink; Organothiophosphorus Compounds; Phenylcarbamates; Random Allocation; Treatment Outcome
PubMed: 30243298
DOI: 10.1186/s13028-018-0412-6 -
Toxicology Research Mar 2018Research has shown that organophosphorus pesticides impair glucose homeostasis and cause insulin resistance and type 2 diabetes. The current study investigates the...
Research has shown that organophosphorus pesticides impair glucose homeostasis and cause insulin resistance and type 2 diabetes. The current study investigates the influence of phoxim on insulin signaling pathways and the protective effects of vitamin E. Phoxim (180 mg kg) and VE (200 mg kg) were administered orally to Sprague-Dawley rats over a period of 28 consecutive days. After exposure to phoxim, the animals showed glucose intolerance and hyperinsulinemia during glucose tolerance tests, and insulin tolerance tests demonstrated an impaired glucose-lowering effect of insulin. Phoxim increases the fasting glucose, insulin and cholesterol levels, as well as the liver hexokinase activity (HK) significantly while decreasing the high density lipoprotein (HDL) cholesterol, and glycogen content in the liver and skeletal muscles observably. Furthermore, we observed an increase of insulin resistance biomarkers and a decrease of insulin sensitivity indices. The insulin receptor substrate (IRS)-2 mRNA expressions of liver and skeletal muscles were down-regulated by phoxim, while the expression of IRS-1 showed no difference. There were no differences in triglycerides, LDL-cholesterol, and fasting glucose treated with phoxim. On the basis of biochemical and molecular findings, phoxim has been determined to impair glucose homeostasis through insulin resistance and insulin signaling pathway disruptions resulting in a reduced function of insulin in hepatocytes and muscles. VE supplementation reduced the fasting glucose, increased the glycogen content and HDL-cholesterol, but did not reduce the insulin resistance indices, when phoxim-treated rats were compared to VE supplemented rats. Overall, this study shows that vitamin E modifies the phoxim toxicity in rats only to a moderate degree.
PubMed: 30090575
DOI: 10.1039/c7tx00243b -
Parasites & Vectors Jul 2018Besnoitiosis is caused by different species of intracellular protozoan parasites belonging to the family Sarcocystidae and affecting multiple host species worldwide....
BACKGROUND
Besnoitiosis is caused by different species of intracellular protozoan parasites belonging to the family Sarcocystidae and affecting multiple host species worldwide. Including B. besnoiti, ten species are described infecting animals. Among ungulates, Besnoitia bennetti infects horses, donkeys and zebras and was described in Africa and in the USA where donkey besnoitiosis is considered as an emerging disease.
CASE PRESENTATION
A two-year-old male donkey was purchased in May 2016 in poor body condition (cachexia, alopetic areas and pruritus mainly on neck and head) by the present owner in Le Roeulx (Belgium) from a milk producing donkey farm in Frasnes-lez-Buissenal (Belgium). Shortly after its purchase and shearing, the donkey presented with crusts, hyperkeratosis (both flanks and neck) anorexia and cachexia. A treatment with phoxim was given with no improvement. A cutaneous biopsy of hyperkeratotic skin was performed in July. It showed a perivascular eosinophilic infiltrate with a large thick walled cyst located in the dermis containing numerous bradyzoites. This was highly suggestive of besnoitiosis. Several skin biopsy samples were obtained for qPCR analysis and confirmed the presence of Besnoitia spp. DNA. Further laboratory diagnosis tests were performed (western blot and rDNA sequencing) confirming Besnoitia bennetti aetiology for the male. For the female, the punch-biopsy, haematology and qPCR were negatives but the western blot showed the presence of antibodies directed to Besnoitia spp. Further clinical examination performed in August highlighted scleral pinhead sized cysts (pearl) in the right eye and between nares. Another ten-year-old female donkey purchased in France and sharing the same accommodation showed a good clinical condition, but a thorough clinical examination showed the presence of numerous cysts on the inner face of upper labial mucosa. A daily treatment based on sulfamethaxzole and trimethoprim (Emdotrim 60% Mix®, 30 mg/kg) was given orally and some improvement was noticed.
CONCLUSION
This is the first evidence of Besnoitia bennetti infection (Protozoa: Apicomplexa) in donkeys (Equus asinus) in Belgium.
Topics: Animals; Base Sequence; Belgium; Coccidiosis; DNA, Protozoan; DNA, Ribosomal; Equidae; Female; France; Male; Phylogeny; Polymerase Chain Reaction; Sarcocystidae; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 30021659
DOI: 10.1186/s13071-018-2993-3 -
Parasites & Vectors Jun 2018The poultry red mite Dermanyssus gallinae negatively impacts bird welfare and health, and interferes with egg production and quality, while emerging acaricide resistance...
BACKGROUND
The poultry red mite Dermanyssus gallinae negatively impacts bird welfare and health, and interferes with egg production and quality, while emerging acaricide resistance limits control options. Fluralaner, a novel miticide for administration in drinking water, is approved for control of D. gallinae infestations. Mite sensitivity testing is relevant to gauge field isolate susceptibility to available treatments.
METHODS
Thirteen D. gallinae isolates collected during 2014 through 2016 from farms in Germany, France, Spain and Brazil, and a 2001 laboratory-maintained isolate were used for acaricide contact sensitivity testing. Tested compounds were cypermethrin, deltamethrin, phoxim, propoxur, and the recently available acaricides, spinosad and fluralaner. In each study, at least one isolate was exposed to increasing concentrations of at least one acaricide. In one study, additional testing determined the sensitivity of the 2001 isolate to fluralaner using a mite-feeding test, and of fluralaner, phoxim and spinosad using an immersion test. At least two replicates were used for each dilution. Vehicle and untreated controls were also included.
RESULTS
Based on 90% mortality (LC) values, the laboratory isolate was susceptible to fluralaner (15.6-62.5 parts per million, ppm), phoxim (< 500 ppm), propoxur (< 125 ppm), and deltamethrin (500-1000 ppm). All field isolates remained sensitive to fluralaner concentrations ≤ 125 ppm. Spinosad LC values for laboratory and field isolates ranged between 2000-4000 ppm. For phoxim, relative to the laboratory isolate, there was reduced sensitivity of two German isolates (LC up to 4000 ppm) and two French isolates (> 4000 ppm). An isolate from Spain demonstrated reduced sensitivity to phoxim, propoxur and deltamethrin; an isolate from Brazil showed reduced sensitivity to propoxur and cypermethrin. Mite LC when exposed to fluralaner by blood feeding was < 0.1 ppm.
CONCLUSIONS
Contact sensitivity testing indicated apparent resistance to at least one of phoxim, deltamethrin, cypermethrin and propoxur in 13 field isolates from Europe and Brazil. All isolates were highly susceptible to fluralaner. Fluralaner was approximately 1000 times more active by feeding than by contact. Fluralaner's distinct mode of action and efficacy against isolates largely refractory to those acaricides, makes it a promising option for the control of D. gallinae infestations of poultry.
Topics: Acaricides; Animals; Brazil; Europe; Isoxazoles; Mites; Nitriles; Pyrethrins
PubMed: 29941050
DOI: 10.1186/s13071-018-2956-8 -
Bacterial communities in natural versus pesticide-treated Aphis gossypii populations in North China.MicrobiologyOpen Mar 2019The cotton-melon aphid, Aphis gossypii Glover, is a worldwide-spreading species, and pesticide-resistant populations are increasing rapidly. In this study,...
The cotton-melon aphid, Aphis gossypii Glover, is a worldwide-spreading species, and pesticide-resistant populations are increasing rapidly. In this study, investigations were performed based on Illumina HiSeq sequencing of the 16S rDNA V4 region for the bacterial communities embodied as intracellular symbionts under natural and in pesticide-treated populations of A. gossypii. The results revealed that more than 82% of bacterial communities belonged to the phylum Proteobacteria in which the maximum proportion (53.24%) was of the genus Arsenophonus; Hamiltonella composed 22.31; and 1.37% was of the genus Acinetobacter. The relative abundance of Hamiltonella was obvious, vertically transmitted, divided into two groups, and its infection influenced the bacterial communities in A. gossypii. Symbiont density and composition were changed in samples tested on different days. Azadirachtin and phoxim influenced on the composition of bacterial communities. Different biomarkers were used for pesticide-treated samples with LEfSe results. These findings will increase awareness regarding bacterial communities in naturally occurring populations of A. gossypii and pave the way to study the relationship between symbionts and pesticide resistance.
Topics: Animals; Aphids; China; Cluster Analysis; DNA, Bacterial; DNA, Ribosomal; Microbiota; Pesticides; Phylogeny; RNA, Ribosomal, 16S; Sequence Analysis, DNA
PubMed: 29877631
DOI: 10.1002/mbo3.652 -
Parasites & Vectors Aug 2017Northern fowl mites (Ornithonyssus sylviarum) are obligate hematophagous ectoparasites of both feral birds and poultry, particularly chicken layers and breeders. They... (Comparative Study)
Comparative Study
Comparative in vitro evaluation of contact activity of fluralaner, spinosad, phoxim, propoxur, permethrin and deltamethrin against the northern fowl mite, Ornithonyssus sylviarum.
BACKGROUND
Northern fowl mites (Ornithonyssus sylviarum) are obligate hematophagous ectoparasites of both feral birds and poultry, particularly chicken layers and breeders. They complete their entire life-cycle on infested birds while feeding on blood. Infestations of O. sylviarum are difficult to control and resistance to some chemical classes of acaricides is a growing concern. The contact susceptibility of O. sylviarum to a new active ingredient, fluralaner, was evaluated, as well as other compounds representative of the main chemical classes commonly used to control poultry mite infestations in Europe and the USA.
METHODS
Six acaricides (fluralaner, spinosad, phoxim, propoxur, permethrin, deltamethrin) were dissolved and serially diluted in butanol:olive oil (1:1) to obtain test solutions used for impregnation of filter paper packets. A carrier-only control was included. Thirty adult northern fowl mites, freshly collected from untreated host chickens, were inserted into each packet for continuous compound exposure. Mite mortality was assessed after incubation of the test packets for 48 h at 75% relative humidity and a temperature of 22 °C.
RESULTS
Adult mite LC /LC values were 2.95/8.09 ppm for fluralaner, 1587/3123 ppm for spinosad, 420/750 ppm for phoxim and 86/181 ppm for propoxur. Permethrin and deltamethrin LC values could not be calculated due to lack of mortality observed even at 1000 ppm.
CONCLUSIONS
Northern fowl mites were highly sensitive to fluralaner after contact exposure. They were moderately sensitive to phoxim and propoxur, and less sensitive to spinosad. Furthermore, the tested mite population appeared to be resistant to the pyrethroids, permethrin and deltamethrin, despite not being exposed to acaricides for at least 10 years.
Topics: Acaricides; Animals; Chickens; Drug Combinations; Drug Resistance; Europe; Macrolides; Mite Infestations; Mites; Nitriles; Organothiophosphorus Compounds; Permethrin; Poultry Diseases; Propoxur; Pyrethrins
PubMed: 28768553
DOI: 10.1186/s13071-017-2289-z -
Scientific Reports Jan 2017Aminoacyl-tRNA synthetases are the key enzymes for protein synthesis. Glycine, alanine, serine and tyrosine are the major amino acids composing fibroin of silkworm....
Aminoacyl-tRNA synthetases are the key enzymes for protein synthesis. Glycine, alanine, serine and tyrosine are the major amino acids composing fibroin of silkworm. Among them, the genes of alanyl-tRNA synthetase (AlaRS) and glycyl-tRNA synthetase (GlyRS) have been cloned. In this study, the seryl-tRNA synthetase (SerRS) and tyrosyl-tRNA synthetase (TyrRS) genes from silkworm were cloned. Their full length are 1709 bp and 1868 bp and contain open reading frame (ORF) of 1485 bp and 1575 bp, respectively. RT-PCR examination showed that the transcription levels of SerRS, TyrRS, AlaRS and GlyRS are significantly higher in silk gland than in other tissues. In addition, their transcription levels are much higher in middle and posterior silk gland than in anterior silk gland. Moreover, treatment of silkworms with phoxim, an inhibitor of silk protein synthesis, but not TiO NP, an enhancer of silk protein synthesis, significantly reduced the transcription levels of aaRS and content of free amino acids in posterior silk gland, therefore affecting silk protein synthesis, which may be the mechanism of phoxim-silking disorders. Furthermore, low concentration of TiO NPs showed no effect on the transcription of aaRS and content of free amino acids, suggesting that TiO NPs promotes silk protein synthesis possibly by increasing the activity of fibroin synthase in silkworm.
Topics: Amino Acid Sequence; Amino Acids; Animals; Bombyx; Cloning, Molecular; DNA, Complementary; Evolution, Molecular; Gene Expression; Metal Nanoparticles; Open Reading Frames; Phylogeny; Serine-tRNA Ligase; Titanium; Tyrosine-tRNA Ligase
PubMed: 28134300
DOI: 10.1038/srep41563 -
Parasites & Vectors Aug 2015Culicoides biting midges are biological vectors of internationally important arboviruses of livestock and equines. Insecticides are often employed against Culicoides as...
BACKGROUND
Culicoides biting midges are biological vectors of internationally important arboviruses of livestock and equines. Insecticides are often employed against Culicoides as a part of vector control measures, but systematic assessments of their efficacy have rarely been attempted. The objective of the present study is to determine baseline susceptibility of multiple Culicoides vector species and populations in Europe and Africa to the most commonly used insecticide active ingredients. Six active ingredients are tested: three that are based on synthetic pyrethroids (alpha-cypermethrin, deltamethrin and permethrin) and three on organophosphates (phoxim, diazinon and chlorpyrifos-methyl).
METHODS
Susceptibility tests were conducted on 29,064 field-collected individuals of Culicoides obsoletus Meigen, Culicoides imicola Kieffer and a laboratory-reared Culicoides nubeculosus Meigen strain using a modified World Health Organization assay. Populations of Culicoides were tested from seven locations in four different countries (France, Spain, Senegal and South Africa) and at least four concentrations of laboratory grade active ingredients were assessed for each population.
RESULTS
The study revealed that insecticide susceptibility varied at both a species and population level, but that broad conclusions could be drawn regarding the efficacy of active ingredients. Synthetic pyrethroid insecticides were found to inflict greater mortality than organophosphate active ingredients and the colony strain of C. nubeculosus was significantly more susceptible than field populations. Among the synthetic pyrethroids, deltamethrin was found to be the most toxic active ingredient for all species and populations.
CONCLUSIONS
The data presented represent the first parallel and systematic assessment of Culicoides insecticide susceptibility across several countries. As such, they are an important baseline reference to monitor the susceptibility status of Culicoides to current insecticides and also to assess the toxicity of new active ingredients with practical implications for vector control strategies.
Topics: Africa; Animals; Biological Assay; Ceratopogonidae; Europe; Insect Vectors; Insecticides; Organophosphates; Parasitic Sensitivity Tests; Pyrethrins; Survival Analysis
PubMed: 26310789
DOI: 10.1186/s13071-015-1042-8 -
Scientific Reports Jul 2015CeCl3 can reduce the damage caused by OP pesticides, in this study we used the brain of silkworms to investigate the mechanism of CeCl3 effects on pesticide resistance....
CeCl3 can reduce the damage caused by OP pesticides, in this study we used the brain of silkworms to investigate the mechanism of CeCl3 effects on pesticide resistance. The results showed that phoxim treatments led to brain damages, swelling and death of neurons, chromatin condensation, and mitochondrial damage. Normal nerve conduction was severely affected by phoxim treatments, as revealed by: increases in the contents of neurotransmitters Glu, NO, and ACh by 63.65%, 61.14%, and 98.54%, respectively; decreases in the contents of 5-HT and DA by 53.19% and 43.71%, respectively; reductions in the activities of Na(+)/K(+)-ATPase, Ca(2+)/Mg(2+)-ATPase, and AChE by 85.27%, 85.63%, and 85.63%, respectively; and increase in the activity of TNOS by 22.33%. CeCl3 pretreatment can significantly reduce such damages. Results of DGE and qRT-PCR indicated that CeCl3 treatments significantly upregulated the expression levels of CYP4G23, cyt-b5, GSTs-σ1, ace1, esterase-FE4, and β-esterase 2. Overall, phoxim treatments cause nerve tissue lesions, neuron death, and nerve conduction hindrance, but CeCl3 pretreatments can promote the expression of phoxim resistance-related genes in silkworm brains to reduce phoxim-induced damages. Our study provides a potential new method to improve the resistance of silkworms against OP pesticides.
Topics: Animals; Bombyx; Brain; Cerium; Enzymes; Gene Expression Regulation; Insect Proteins; Insecticides; Larva; Neurotoxicity Syndromes; Neurotransmitter Agents; Organothiophosphorus Compounds; Protective Agents; Toxicity Tests
PubMed: 26227613
DOI: 10.1038/srep12761