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Objective To explore the residual level of FPMs in indoor dust samples in Shenzhen from 2020 and 2021, and to analyze its temporal distribution characteristics. Methods In the present study, indoor dust samples (n=193) from residential buildings in Shenzhen. were collected to analyze the temporal variation characteristics of FPMs. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was applied to determine the concentrations of FP and its four major metabolites (fipronil-sulfone, fipronil-sulfide, fipronil-desulfinyl, and fipronil-amide; abbreviated as FP-SFO, FP-SFI, FP-DES, and FP-AM) in the samples. The sum of the concentrations of FP and its four metabolites was represented as additive mass concentration (ΣFPMs). Additionaly, Wilcoxon test was performed to determine the temporal distribution differences of FPMs’ concentrations. Results From 2020 to 2021, the concentration of ΣFPMs for the in door dust samples in Shenzhen ranged from 0.51 to 4 415 ng/g (median: 18.8ng/g). FP, FP-SFO AND FP-SFI were the major target analytes in the sample with detection rates of 90.60%，86.20% and 75.40%, respectively. The detection rates of other metabolites were low (≤ 44.3%). Analysis of the temporal variation trend of FPMs’ concentrations showed that there was no significant difference in the levels of ΣFPMs between warm season（spring and summer）and cold season（autumn and winter）in the indoor dust samples from 2020 to 2021(2.38 vs 2.84ng/g , P > 0.05). However , the concentrations of FP-SFI and ΣFPMs in the indoor dust samples collected from 2021 showed an significantly increasing trend compared with 2020（1.02 vs 1.89 , 17.80vs. 20.10 ng/g , P < 0.05). Conclusion From 2020 to 2021 , the detection level of FPMs in indoor dust in Shenzhen is relatively high and shows an upward trend , with no obvious seasonal difference. However, whether the residual level of FPMs in indoor dust poses a risk to human health needs further study.
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@#Abstract: Objective In order to explore the application prospects of the phenyl pyrazole insecticide fipronil for mosquito control and identify potential target genes involved in the resistance of Aedes aegypti to fipronil, and lay the foundation for an in-depth study of the resistance mechanism of Aedes aegypti to fipronil. Methods Using Aedes aegypti sensitive strains as experimental materials, Aedes aegypti larvae were treated with fipronil, and the differences in gene expression of Aedes aegypti larvae before and after drug administration were compared at the transcriptome level using transcriptome sequencing combined with bioinformatics analysis, and the differential genes were analyzed. Results A total of 757 differentially expressed genes were identified between the fipronil-treated group and control group, including 217 and 540 up- and down-regulated genes, respectively. Among these, the expression of glutamate-gated chloride channel (GluCls) genes varied significantly before and after treatment. Gene ontology analysis revealed that differentially expressed genes were enriched in catalytic activity, binding, metabolic processes, and membrane-related functions, while KEGG pathway analysis indicated enrichment in biosynthesis, metabolism, and life regulation processes, while the glutathione metabolic pathway was enriched in 15 differentially expressed genes. Conclusions The transcriptome results revealed that GST gene expression was significantly upregulated in fipronil-treated Aedes aegypti larvae, indicating that GST gene is involved in the development of fipronil resistance in Aedes aegypti larvae. In addition, GluCls gene expression was also significantly different before and after treatment, suggesting that GluCls migh be a potential target receptor for fipronil resistance in Aedes aegypti. As GluCls is an ideal target receptor found only in invertebrates, this discovery provides a reference and basis for further exploration of the toxicological mechanism of fipronil on Aedes aegypti.
ABSTRACT
Fipronil was registered in Uruguay in 1997, and, since then, it has been used for the control of Haematobia irritans irritans and Rhipicephalus microplus. The susceptibility of H. irritants to this drug has not been evaluated. Therefore, the goal of the present study was to evaluate the resistance of H. irritans to fipronil. Additionally, a survey was carried out with the farmers to evaluate the use of fipronil for H. irritans control in the ranches where the flies came from. For the bioassays, 31 field populations of H. irritans were exposed to 10 concentrations of fipronil (3.2-16.0μg.cm2), and their LC50 values were calculated using probit analysis. A bioassay was performed with horn flies from the susceptible colony maintained at the USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory for comparison and calculation of resistance ratios (RRs). All 31 field populations surveyed in the study were susceptible to fipronil, with resistance ratios ranging from <0.5 to 2.2. Four populations with RRs >1 did not differ significantly from the susceptible strain. A single population showed an RR >2.2. Overall, the survey shows that fipronil was mostly used for R. microplus control, and in only three ranches, which were free of R. microplus, was fipronil used for horn fly control. Seventeen farmers did not use fipronil at all in the last three years. It is concluded that, in Uruguay, field populations of horn flies remain susceptible to fipronil.(AU)
O fipronil foi registrado no Uruguai em 1997 e, desde então, tem sido utilizado no controle de Haematobia irritans irritans e Rhipicephalus microplus. O objetivo do presente estudo foi avaliar a susceptibilidade de populações de campo de H. irritans ao fipronil. Além disso, foi realizada uma pesquisa para avaliar a utilização de fipronil e as práticas de controle de H. irritans nas fazendas de onde provinham as moscas. Para os bioensaios, 31 populações de campo de H. irritans foram expostas a 10 concentrações de fipronil (3,2-16,0μg.cm2), e seus valores de CL50 foram calculados usando análise probit. Um bioensaio foi realizado com H. irritans da colônia suscetível mantida no USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory para comparação e cálculo das razões de resistência (RRs). Todas as 31 populações de campo pesquisadas no estudo eram suscetíveis ao fipronil, com taxas de resistência variando de <0,5 à 2,2. Quatro populações com Rrs >1 não diferiram significativamente da cepa suscetível. Uma única população apresentou RR >2,2. No geral, o fipronil tinha sido usado principalmente para o controle de R. microplus, e em apenas três fazendas, que estavam livres de R. microplus, o fipronil era utilizado para o controle da H. irritans. Em 17 fazendas não tinha sido utilizado fipronil nos últimos três anos. Conclui-se que no Uruguai as populações de H. irritans no campo permanecem suscetíveis ao fipronil.(AU)
Subject(s)
Animals , Cattle , Biological Assay , Pest Control, Biological , Rhipicephalus/pathogenicity , Diptera , Livestock , Surveys and Questionnaires , Disease Susceptibility , LaboratoriesABSTRACT
ABSTRACT: Fipronil was registered in Uruguay in 1997, and, since then, it has been used for the control of Haematobia irritans irritans and Rhipicephalus microplus. The susceptibility of H. irritants to this drug has not been evaluated. Therefore, the goal of the present study was to evaluate the resistance of H. irritans to fipronil. Additionally, a survey was carried out with the farmers to evaluate the use of fipronil for H. irritans control in the ranches where the flies came from. For the bioassays, 31 field populations of H. irritans were exposed to 10 concentrations of fipronil (3.2-16.0g.cm2), and their LC50 values were calculated using probit analysis. A bioassay was performed with horn flies from the susceptible colony maintained at the USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory for comparison and calculation of resistance ratios (RRs). All 31 field populations surveyed in the study were susceptible to fipronil, with resistance ratios ranging from 0.5 to 2.2. Four populations with RRs >1 did not differ significantly from the susceptible strain. A single population showed an RR >2.2. Overall, the survey shows that fipronil was mostly used for R. microplus control, and in only three ranches, which were free of R. microplus, was fipronil used for horn fly control. Seventeen farmers did not use fipronil at all in the last three years. It is concluded that, in Uruguay, field populations of horn flies remain susceptible to fipronil.
RESUMO: O fipronil foi registrado no Uruguai em 1997 e, desde então, tem sido utilizado no controle de Haematobia irritans irritans e Rhipicephalus microplus. O objetivo do presente estudo foi avaliar a susceptibilidade de populações de campo de H. irritans ao fipronil. Além disso, foi realizada uma pesquisa para avaliar a utilização de fipronil e as práticas de controle de H. irritans nas fazendas de onde provinham as moscas. Para os bioensaios, 31 populações de campo de H. irritans foram expostas a 10 concentrações de fipronil (3,2-16,0g.cm2), e seus valores de CL50 foram calculados usando análise probit. Um bioensaio foi realizado com H. irritans da colônia suscetível mantida no USDA-ARS Knipling-Bushland U.S. Livestock Insects Research Laboratory para comparação e cálculo das razões de resistência (RRs). Todas as 31 populações de campo pesquisadas no estudo eram suscetíveis ao fipronil, com taxas de resistência variando de 0,5 à 2,2. Quatro populações com Rrs >1 não diferiram significativamente da cepa suscetível. Uma única população apresentou RR >2,2. No geral, o fipronil tinha sido usado principalmente para o controle de R. microplus, e em apenas três fazendas, que estavam livres de R. microplus, o fipronil era utilizado para o controle da H. irritans. Em 17 fazendas não tinha sido utilizado fipronil nos últimos três anos. Conclui-se que no Uruguai as populações de H. irritans no campo permanecem suscetíveis ao fipronil.
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Objective To study the first-time killing efficacy and the chain-killing efficacy of four gel baits against Blattella germanica: 1% chlorpyrifos, 0.05% fipronil, 2.15% imidacloprid, and 0.5% dinotefuran and provide a basis for drug selection in controlling Blattella germanica. Methods Laboratory killing efficacy test was conducted according to the national standard GB/T 13917.7-2009 and the chain-killing efficacy test was conducted for three rounds.The first round of chain efficacy test was conducted by feeding the cockroaches killed in the laboratory efficacy test, and each next round by feeding the cockroaches killed in the last round.Median lethal time (LT50), 95% confidence limit, and toxicological regression equation of each test were calculated by software DPS V9.01. Results The LT50 of the efficacy test with 1% chlorpyrifos gel bait was 0.745 5 (0.603 4-0.890 3) d.The LT50 of the first, second and third chain experiments increased by 3.30, 2.18 and 2.76 times, respectively.The LT50 of the efficacy test with 0.05% fipronil gel bait was 0.846 5(0.464 7-1.228 0)d, and increased by 5.42, 2.09 and 1.48 times, respectively, in the first, second and third chain experiments.The LT50 of the efficacy test with 2.15% imidacloprid gel bait was 3.192 1(2.865 0-3.506 0)d, and increased by 1.13, 1.65 and 1.15 times, respectively in the first, second and third chain experiments.The LT50 of the efficacy test with 0.5% dinotefuran gel bait was 0.997 1(0.805 8-1.191 6) d, and increased by 3.85, 1.37 and 1.78 times, respectively in the first, second and third chain experiments. Conclusion In the laboratory killing efficacy test, 1% chlorpyrifos, 0.05% fipronil, and 0.5% dinotefuran gel baits are better than 2.15% imidacloprid gel bait.In the chain-killing efficacy test, 2.15% imidacloprid and 0.5% dinotefuran gel baits are better than 1% chlorpyrifos and 0.05% fipronil gel baits.Based on our results, we recommend the use of 0.5% dinotefuran gel bait for comprehensive and sustained killing effect.
ABSTRACT
Residues of plant protection products have been reported in floral resources such as pollen, but the potential risks of pollinator exposure are still unclear. Therefore, studies are needed to assess the risk of exposure/intoxication of bees, as they collect these resources to maintain their colony. The present study used a randomized design with five treatments: thiamethoxam, clothianidin, imidacloprid, fipronil, and a control. Pollen was collected from two soybean plants per repetition during their entire flowering period, mixed with 8 g of sugar cake (distilled water + sugar), and offered to adult bees that were then followed for the assessment of mortality over time (1, 2, 4, 8, 16, 24 and 32 h after initial exposure). Among the generalized linear models evaluated, the beta binomial model was the best fit. The treatments were compared within each time period by overlapping credibility intervals using Bayesian inference. The probability of bee mortality was low in the first hours of evaluation and gradually increased over time in all chemical treatments. When comparing the means of the beta-binomial model, no statistical differences among treatments was observed, indicating a mortality similar to that of the control group.(AU)
Resíduos de produtos de proteção de plantas têm sido relatados em recursos florais como o pólen, mas os potenciais riscos da exposição aos polinizadores ainda não estão claros. Portanto, tornam-se necessários estudos para avaliar o risco da exposição/intoxicação das abelhas, já que necessitam destes recursos para a manutenção da colônia. O presente estudo utilizou um delineamento inteiramente ao acaso com cinco tratamentos: tiametoxam, clotianidina, imidacloprid, fipronil e testemunha. O pólen foi coletado durante todo o período de floração de duas plantas de soja por repetição e incorporado a 8 g de pasta candi (água destilada + açúcar), e oferecido às abelhas adultas e logo após foi avaliada a mortalidade ao longo do tempo (1, 2, 4, 8, 16, 24 e 32 h após a exposição inicial). Dentre os modelos lineares generalizados testados o modelo do tipo beta binomial foi o que melhor se ajustou. Os tratamentos foram contrastados dentro de cada intervalo de tempo pela sobreposição dos intervalos de credibilidade através Inferência Bayesiana. A probabilidade de mortalidade das abelhas foi pequena nas primeiras horas de avaliação, aumentando gradativamente ao longo do tempo em todos os tratamentos. Ao comparar as médias do modelo beta-binomial, não foram observadas diferenças estatísticas entre os tratamentos, indicando uma mortalidade padrão inclusive na testemunha.(AU)
Subject(s)
Pollen , Soybeans , Bees , Seeds , Apis mellifica , Mortality , Thiamethoxam , HymenopteraABSTRACT
Immunotoxicity is defined as adverse effects on the functioning of the immune system that results from exposure to chemical substances. The present investigation was carried out to evaluate immunomodulating effect of Morus alba (500mg/kg B.w.) against immunotoxicity induced by sub-acute exposure of Fipronil (10mg/kg B.w.) in rats. Sub-acute immunotoxicity was conducted in adult male wistar rats. Rats were randomly divided into four groups (6 rats/group). Group I served as control in which corn oil (acting as a vehicle of Fipronil) was administered @10 ml/kg B.w. Group II served as Fipronil treated group @10 mg/kg B.w. In Group III Fipronil along with Morus alba fruits extract @ 300 mg/kg B.w. was administered and in Group IV Morus alba fruits extract @ 300 mg/kg B.w. was administered. Vehicle, Fipronil and Morus alba were administered daily to the rats by oral gavage for 28 days. The dose of fipronil was selected on the basis of LD50 in rats. TLC, DLC, serum total protein, albumin, globulin, A:G ratio, serum antibody titer/haemagglutination (HA) titer and delayed type hypersensitivity (DTH) response were estimated. Fipronil produced immunotoxicity in the form of alteration from normal values in these parameters. Morus alba was significantly effective in restoration of these parameters towards normal. The study suggested that Morus alba has immunomodulating potential against toxicity induced by fipronil in rats.
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Objective: To establish a method for the determination of fipronil and its metabolites in vegetables by ultra performance liquid chromatography-quadrupole-electrostatic field/orbital trap high resolution mass spectrometry. Methods: After homogenizing the vegetable samples, acetonitrile was added for ultrasonic extraction, then sodium chloride and anhydrous sodium sulfate were added to remove water. Finally, N- propyl ethylenediamine(PSA)powder, C18 powder and anhydrous sodium sulfate were added to remove impurities and purify the samples. Thermo Syncronis C18 column(100 mm×2.1 mm, 1.7 μm)was used for chromatographic separation of the samples. Data were collected under the Full MS-ddMS2 scanning mode of Q-Exactive high resolution mass spectrometry for qualitative and quantitative analysis. Results: The linearity of fipronil and its metabolites was good in the concentration range of 0.1-5.0 μg/L, and the correlation coefficient r2 were all greater than 0.9900. The average recovery of each component was 95.4%-108.6%, RSD was 0.769-5.563%, and RSD within 24 hours was 1.531%-4.959%. Conclusion: The present method appears to be simple, rapid, reproducible, stable and sensitive, which is suitable for rapid qualitative and quantitative detection of fipronil and its metabolites in vegetables.
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Objective@#To understand the status and health risk assessment of dietary fipronil contamination among 20 provinces of China.@*Methods@#A total of 13 kinds of dietary samples in Chinese total diet study include cereals, legumes, potatoes, meats, eggs, aquatics, dairies, vegetables, fruits, sugars, beverages and water, alcohols, condiments and their corresponding products. Among them, condiments were used in the preparation of 12 other sample categories; thus, the actual mixed dietary samples of each province covered 12 groups. A total of 240 mixed dietary samples were collected from 20 provinces in China from 2009 to 2013. After the sample extraction and cleanup, dietary samples were analyzed for the residues of fipronil and its metabolites to obtain the contamination levels of fipronil residues using liquid chromatography-high resolution mass spectrometry. The dietary intake of adult residents was estimated based on food consumption of general population of China.@*Results@#Among the 240 dietary samples, the detection rate of fipronil was 10.4% (25 samples), and the detection rates of fipronil metabolites, i.e. fipronil desulfinyl, fipronil sulfone and fipronil sulfide were 20.4% (49 samples), 40.0% (96 samples) and 8.8% (21 samples), respectively. According to the dietary exposure analysis, the average lower and upper dietary exposure levels of fipronil residues in adult residents of China were 11.34 and 12.35 ng·kg-1·d-1, accounting for 5.7% and 6.2% of acceptable daily intake (ADI), respectively. The highest adult dietary intake of fipronil residues was found in Hunan province, with a value of 72.98 ng·kg-1·d-1, accounting for 36.5% of ADI. Vegetables were the main dietary source of fipronil residues, which contributed to 71.0% of the total intake dose.@*Conclusion@#Fipronil residues were detected in varying degrees in dietary samples, yet the health risk caused by the dietary intake of adult residents among 20 provinces of China is low.
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En este trabajo se describe la resistencia de una población Rhipicephalus microplus resistente al fipronil 1% (ECTOLINE®) en condiciones de campo en el este de Santiago del Estero, Argentina. Las pruebas fueron realizadas a modo de réplicas en dos establecimientos: "Establecimiento A" y "Establecimiento B". En el Establecimiento A las diferencias en los niveles de infestación con garrapatas entre los grupos tratado y control nunca fueron estadísticamente significativas. Los porcentajes de eficacia oscilaron entre 27,3% y 69,3%. En el Establecimiento B las diferencias entre los grupos tratado y control fueron significativas, con porcentajes de eficacia aumentando de 87,6% el día 2 post-tratamiento a 95,4% el día 7 post-tratamiento. Las tasas de eclosión de los huevos originados de las teleóginas colectadas de los grupos tratados y control en el Establecimiento A fueron similares. La aplicación de fipronil 1% en el Establecimiento B tuvo una eficacia global prácticamente absoluta, porque si bien la eficacia terapéutica no alcanzó el 100%, la viabilidad reproductiva de las teleóginas obtenidas de los bovinos tratados fue nula. Los resultados del presente trabajo constituyen el primer registro publicado de una población de R. microplus resistente al fipronil 1% en condiciones de campo en Argentina.
The resistance of a population of Rhipicephalus microplus (Acari: Ixodidae) to fipronil 1% (ECTOLINE®) in the east of Santiago del Estero, Argentina, is described in this work. The trials were performed as replicates in two establishments: "Establishment A" and "Establishment B". The differences in the level of tick infestation between treated and control groups in the Establishment A were not significant. The efficacy percentage ranged from 27.3% to 69.3%. Contrarily, the differences between treated and control groups in the Establishment B were significant, with efficacy percentage increasing from 87.6% (day 2 post-treatment) to 95.4% (day 7 post-treatment). The eclosion rates of the eggs produced by the engorged females collected in both treated and control groups in Establishment A were similar. The application of fipronil 1% in the Establishment B had an efficacy almost absolute, because even though the therapeutic efficacy did not reach 100%, the reproductive viability of the engorged females collected on the treated cattle was null. The results of this work constitute the first published record of a population of R. microplus resistant to fipronil 1% under field conditions in Argentina.
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The study was conducted in order to evaluate the effect of a fipronil/(S)-methoprene formulation against fleas on naturally infested cats. The study involved a population of 89 cats distributed among 24 veterinary practices in 9 regions of Spain. The product was applied according to label instructions on days 0, 30 and 60. Animals underwent parasitological and clinical assessments on day 0 and thereafter in monthly intervals (every 30 days) until day 90. Ctenocephalides felis was the most abundant species (98.9% of all fleas collected), and flea abundance on Day 0 was associated with the hair type, the location of the household, and the time elapsed from the last anti-flea treatment. Fipronil/(S)-methoprene demonstrated high efficacy and induced the reduction of clinical signs related to the presence of fleas. Clinical signs and flea abundance decreased significantly throughout time (P=0.001) with an efficacy rate of 72.6% at Day 30, 88.4% at Day 60 and 93.9% at Day 90. A high level of flea control and a remission of the clinical signs related to presence of fleas were observed on cats following 3 monthly applications a fipronil/(S)-methoprene formulation.(AU)
Subject(s)
Animals , Cats , Ctenocephalides , Flea Infestations/prevention & control , Insecticides/therapeutic use , Methoprene/therapeutic use , Ectoparasitic Infestations/prevention & controlABSTRACT
Fipronil is a pesticide widely used for controlling fleas and ticks in domestic animals, and its short-term exposure can lead to serious effects on animals. However, the possible genotoxic effect of this compound has not been investigated in target animals. Based on the hypothesis that fipronil can induce genotoxicity, this study evaluated the effect of fipronil on DNA damage in peripheral blood cells. For that purpose, ten dogs of both sexes were used in the study. The product (6.7mg/kg) was applied on the dorsal neck region of each animal. Peripheral blood samples were collected immediately prior to application of the product, and at 3, 8 and 24 hours after the application. Samples were processed for comet assay. No statistically significant differences were found among the four time points. The current study suggests for the first time that a single exposure to this pesticide does not induce systemic genotoxic effect in dogs.(AU)
O fipronil é um inseticida/herbicida amplamente utilizado para controle de pulgas e carrapatos em animais domésticos. Sua exposição a curto prazo tem acarretado efeitos deletérios em animais. Entretanto, o possível efeito genotóxico deste composto ainda não foi investigado em animais alvo. Baseando-se na hipótese de que o fipronil pode induzir genotoxicidade, o presente estudo avaliou o efeito deletério do fipronil no material genético de células de sangue periférico. Para isso, dez cães sadios, de ambos os sexos, foram utilizados neste estudo. O produto (6,7mg/kg) foi aplicado na região dorsal do pescoço de cada animal. As amostras de sangue foram coletadas imediatamente antes da aplicação do produto (controle) e após três, oito e 24 horas da aplicação. As amostras foram imediatamente processadas para condução do teste do cometa, a fim de se avaliar os danos basais no DNA. Não houve diferença significativa entre os quatro momentos de coleta em relação aos danos no material genético. O estudo sugere, pela primeira vez, que uma exposição única a este pesticida não induz efeito genotóxico sistêmico em cães.(AU)
Subject(s)
Animals , Dogs , Genotoxicity/analysis , Pesticides/analysis , Comet Assay/veterinary , DNA DamageABSTRACT
Objective@#To compare the residual distribution of fipronil and its metabolites in white and yellow egg, and to analyze the residual changes of fipronil and its metabolites in raw and cooked samples, regarding the risk assessment of fipronil and its metabolites via consuming egg for different age groups.@*Methods@#The white egg and yellow egg were isolated from 10 egg samples containing fipronil residues. Samples were extracted with acetonitrile and purified, and determined by liquid chromatography-high resolution mass spectrometry. The chromatographic analysis was performed on a BEH C18 column with 0.1% acetic acid and acetonitrile as mobile phase with gradient elution, and external standard calibration was used for quantification. The negative ion acquisition mode was applied and quantitative analysis was carried out by using Full Scan/ddms2 model.@*Results@#The results showed that fipronil sulfone was the main residue detected in eggs; The content of fipronil sulfone in white egg was between 2.5 and 59.9 μg/kg, the median was 16.1 μg/kg; and the content of fipronil sulfone in yellow egg ranged from 81.5 and 1 526.0 μg/kg, with a median of 390.0 μg/kg. The ratio of fipronil sulfone in yellow egg to white egg ranged from 8.0 and 14.6. Compared with that observed in fresh egg, after heating or cooking, the content ratio of fipronil sulfone residue between cooked samples and raw samples from yellow egg was between 0.80 and 0.96, the median was 0.90; and the ratio from white egg ranged from 0.65 to 1.06, the median was 0.83. The conversion coefficient of fipronil sulfone (f) between white egg and yellow egg was 3.1.@*Conclusion@#Yellow egg is a major intake source of fipronil and metabolites residues, and there is no obvious change for fipronil sulfone residue in eggs after heating or cooking. The conversion coefficient of fipronil sulfone (f) between white egg and yellow egg lays the foundation for assessing the health risks of fipronil and metabolites residues through yellow egg intake in special population.
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ABSTRACT The aim of this study was to characterize the mechanism of toxicity of fipronil on hepatocytes isolated from the rat and the effect of its biotransformation on the toxicological potential. The toxicity of fipronil was assessed by monitoring the oxygen consumption and mitochondrial membrane potential, intracellular ATP concentration, Ca2+ homeostasis and cell viability. The cell viability was evaluated by trypan blue exclusion in hepatocytes that were isolated from the normal rats and by the release of the enzymes alanine transaminase and aspartate transaminase in hepatocytes that were isolated from the normal rats or proadifen-pretreated rats. Fipronil reduced mitochondrial respiration in the cells that were energized with glutamate plus malate in a dose-dependent manner and dissipated the mitochondrial membrane potential that was accompanied by a reduction in ATP concentration and a disruption of intracellular Ca2+ homeostasis. The cell viability was affected by fipronil with higher potency in hepatocytes that were isolated from the normal rats, which indicated that the metabolism of this insecticide increased its toxicological potential. The results of this study indicated that the toxicity of fipronil to the hepatocytes was related to the inhibition of mitochondrial activity, which led to decreased ATP synthesis and a consequent alteration in intracellular Ca2+ homeostasis and ultimately resulted in cell death.
ABSTRACT
This study was conducted to show the effectiveness of a novel formulation of fipronil in a spot-on formulation for the therapeutic and preventive control of Rhipicephalus sanguineus in naturally infested dogs. Ticks on all dogs were counted at the moment of treatment and weekly after treatment (therapeutic efficacy) or infestation (preventive efficacy). The profile of the therapeutic efficacy for Rhipicephalus sanguineus suggested that the formulation was able to control the Ixodid species for at least 42 days after the treatment.
Este estudo teve como objetivo avaliar a eficácia de uma nova formulação "spot-on" à base de fipronil na terapêutica e prevenção do parasitismo por Rhipicephalus sanguineus em cães naturalmente infestados. Foi realizada contagem dos carrapatos no momento da aplicação do produto e semanalmente após o tratamento (eficácia terapêutica), bem como avaliando sua reinfestação (eficácia preventiva). Perfis terapêuticos e preventivos sugerem que a formulação controla o parasitismo por R. sanguineus em cães por pelo menos 42 dias após o tratamento.
Subject(s)
Animals , Male , Female , Dogs , Acaricides/administration & dosage , Antiparasitic Agents/administration & dosage , Dog Diseases/drug therapy , Dog Diseases/parasitology , Pyrazoles/administration & dosage , Rhipicephalus sanguineus , Tick Infestations/drug therapy , Tick Infestations/veterinary , Administration, Topical , Brazil , Treatment OutcomeABSTRACT
An examination of a selective control of Rhipicephalus (Boophilus) microplus and consequent cost reduction was carried out in two areas of native pasture in the municipality of Lages, State of Santa Catarina, Southern Brazil, from May 2007 to April 2009. Forty cattle were divided into two groups of 20 animals each (conventional and selective control groups). At 14-day intervals female ticks larger than 4.5 mm found on the right flank of cattle bodies were counted, and these results multiplied by two. Fipronil 1 mg.kg-1 pour on was then administered for tick control. In the conventional group all the cattle were treated when tick count averaged more than 40 female ticks per animal while in the selective group only animals parasitized by more than 40 ticks were treated with acaricide. Every 28 days the cattle's weight was checked for cost-effective analysis. The conventional group required an additional 20 doses of fipronil compared with the selective one. There was no statistically significant differences regarding weight gain in both groups.
Com o objetivo de avaliar o método de controle seletivo do Rhipicephalus (Boophilus) microplus e reduzir os custos para o controle, de maio de 2007 a abril de 2009, em duas invernadas de campo nativo no município de Lages, SC, utilizaram-se 40 bovinos que foram divididos em dois grupos (convencional e seletivo), de 20 animais cada. A cada 14 dias foi realizada a contagem das fêmeas maiores ou igual a 4,5 mm, no lado direito do corpo dos animais, e o valor obtido, multiplicado por dois. Foi utilizado fipronil 1 mg.kg-1 pour on para o controle de carrapatos. No grupo convencional, foram tratados todos os bovinos quando a média do grupo foi igual ou superior a 40 fêmeas e no grupo seletivo, foram tratados apenas os animais que apresentaram uma infestação igual ou superior a 40. A cada 28 dias foi realizada a pesagem dos animais para análise da relação custo/benefício. Foram realizadas 20 aplicações a mais do carrapaticida no grupo convencional em relação ao seletivo. Não houve diferença estatística entre o ganho de peso do grupo convencional em relação ao grupo seletivo.
Subject(s)
Animals , Cattle , Acaricides/therapeutic use , Antiparasitic Agents/therapeutic use , Cattle Diseases/prevention & control , Pyrazoles/therapeutic use , Rhipicephalus , Tick Infestations/veterinary , Brazil , Tick Control/methods , Tick Infestations/prevention & controlABSTRACT
Background & objectives: Resistance amongst cockroaches has been reported to most of the spray insecticides apart from the problem of food contamination and inconvenience. Gel baits which can be selectively applied have been found effective in control of cockroaches in laboratory studies but very few field studies are available. This trial was planned to evaluate the efficacy of fipronil (0.01%) and imidacloprid (2.15%) gels over synthetic pyrethroid (0.02% deltamethrin + 0.13% allethrin) and propoxur (2%) aerosols in control of cockroaches in the field. Methods: Survey was done to find out pre-treatment density in catering establishments and houses by visual count and sticky trap methods. A total of 10 catering establishments and 10 houses having high cockroach infestation were selected by sampling (two catering establishments and houses for each insecticidal treatment and two for control). Propoxur and synthetic pyrethroid aerosols were used for spraying the infested sites once only. Single application of fipronil and imidacloprid gels was used as crack and crevice treatment. Visual count method gave better indications of cockroach infestation as compared to sticky trap method, hence, the same was followed for post-treatment evaluation every week up to 12 weeks. Results: Synthetic pyrethroid could not bring about the desired reduction in cockroach infestation in the present study. Single application of fipronil gel was able to reduce cockroach infestation up to 96.8% at the end of 12 weeks whereas imidacloprid application resulted in 90.9% reduction and propoxur resulted in 77.5%. However, propoxur was more effective in reducing the cockroach density by first week in comparison to imidacloprid and fipronil gels but its efficacy started declining after 8th week. Difference was found statistically significant by Kruskal-Wallis H-test. Conclusion: The study reports the efficacy of propoxur aerosol, imidacloprid gel and fipronil gel baits for control of cockroaches.
ABSTRACT
No presente trabalho, foram avaliadas, comparativamente, duas formulações comerciais tópicas, contendo 10 por cento de fipronil, para o controle da pulga Ctenocephalides felis felis em gatos. O experimento foi realizado no Laboratório de Quimioterapia Experimental em Parasitologia Veterinária do Departamento de Parasitologia Animal, Instituto de Veterinária, da Universidade Federal Rural do Rio de Janeiro. Foram empregados 18 gatos, sem raça definida, divididos em três grupos de seis. Um grupo permaneceu sem tratamento (controle), e os demais foram medicados com uma formulação referência do mercado veterinário ou com uma nova formulação em teste. Os animais tratados receberam 0,5 mL do produto ao longo da região dorso-cervical e foram infestados nos dias - 2, +5, +12, +19, +26 e +33. A primeira avaliação foi realizada quatro dias após a primeira infestação e, as demais, 48 horas após cada infestação, por meio do comb test. Ambas as formulações testadas foram eficazes até o dia +35 após o tratamento, não havendo diferenças entre seus níveis de eficácia ao longo do período experimental. A nova formulação, contendo fipronil a 10 por cento, apresentou a eficácia desejada no controle de C. f. felis em gatos.
The goal of the present study was to evaluate the comparative efficacy of two topical formulations containing 10 percent fipronil on the control of Ctenocephalides felis felis on cats. The trial was performed at the Laboratory of Experimental Chemotherapy in Veterinary Parasitology from the Department of Animal Parasitology of the Institute of Veterinary of the Universidade Federal Rural do Rio de Janeiro. Eighteen mixed-breed cats were divided in three groups of six animals each. One group remained without treatment (control). The other groups received as treatment the two topical formulations, a commercial reference and the novel one, both containing 10 percent fipronil. Treated animals received 0.5 mL of product along their cervical region. Cats were infested on days - 2, +5, +12, +19, +26 and +33. Evaluations were made using the "comb test". The first one was undertaken 4 days after the initial infestation (day +2), and others 48 hours after following infestations (days +7, +14, +21, +28 and + 35). Both tested formulations had satisfactory efficacy until day + 35. No differences were observed comparing the efficacy levels between both formulations troughout the experimental period. The novel topical 10 percent fipronil formulation presented desirable efficacy on the control of C. f. felis on cats.
Subject(s)
Animals , Cats , Cat Diseases/prevention & control , Ectoparasitic Infestations/veterinary , Insecticides/administration & dosage , Pyrazoles/administration & dosage , Siphonaptera , Administration, Topical , Ectoparasitic Infestations/prevention & controlABSTRACT
The rosewood tree (Aniba rosaeodora Ducke) is known for its linalool which provides a strong, fragrant smell in all parts of the plant. Due to its exploitation in the Amazon for its linalool in the use of perfumes, the rosewood is in danger of extinction. Its irregular fruiting increases the difficulty in obtaining seeds for producing seedlings and, in addition, part of its production is lost due to pests attacking the seeds. Due to these factors, the object of this study was to achieve the application of insecticides on seeds and seedlings in nursery to avoid or minimize the attack of pests, thus improving seedling production. 300 seeds were used, distributed into 2 treatments and 1 witness. Each treatment (n = 100) was set for 4 repetitions (trays) with 25 seeds. The insecticide used was acetamiprid and fipronil in concentrations of 0.09 mg / plant and 0.18 mg / plant, respectively for treatment 1 (T1) and the treatment 2 (T2), distributed in the form of "sachês". The T1 received the application from 1 "sachê" and T2 the implementation of two "sachês", buried with washed sand in seaders. The results were evaluated by analysis of Variance (ANOVA) using the Systat 9 program and the averages compared by the Tukey test at 5% of significance. The rates of germination were: witness with 62%; T1 with 73% and T2 with 79%. There was an attack of insects only in the witness treatment with 23% of the total (n = 300), and the results were statistically significant (F = 31.263 p 0.001). There were significant differences only between the height of the seedlings in treatments T1 and T2 and witness treatment (F = 15.090 p 0.001).The main pest identified was Heilipus odoratus (Coleoptera: Curculionidae). We, therefore, recommended the concentration of 0.09 mg of acetamiprid and fipronil distributed in "sachês" in sowing and transplanted to reduce the attack of pests in seeds and seedlings of rosewood in nurseries.
O pau-rosa (Aniba rosaeodora) é conhecido pela presença do álcool linalol, que fornece um odor forte e perfumado em todas as partes da planta. A sua exploração na Amazônia ao longo dos últimos anos, para utilização do linalol como fixador de perfumes, coloca o pau-rosa em risco de extinção, a sua frutificação irregular aumenta a dificuldade em se obter sementes para a produção de mudas e, além disso, parte de sua produção é perdida face ao ataque de pragas nas sementes. Em razão desses fatores o presente estudo teve como objetivo realizar a aplicação de inseticidas nas sementes e mudas em viveiro a fim de evitar ou minimizar o ataque de pragas, aumentando, assim, a produção de mudas. Utilizou-se um total de 300 sementes, distribuídas em 2 tratamentos e 1 testemunha. Cada tratamento (n = 100) foi constituído por 4 repetições (bandejas) com 25 sementes. O inseticida utilizado nos tratamentos foi acetamiprid e fipronil nas concentrações de 0,09 mg/planta e 0,18 mg/planta, respectivamente, para o tratamento 1 (T1) e o tratamento 2 (T2), distribuídos na forma de sachês. O T1 recebeu a aplicação de 1 sachê e o T2 a aplicação de dois sachês, enterrados com areia lavada nas sementeiras. Para avaliar os resultados foi feita uma análise de Variância (ANOVA), usando o programa Systat 9 e as médias comparadas pelo teste de Tukey em nível de 5%. As taxas de germinação foram: testemunha com 62%; T1 com 73% e T2 com 79%. Houve ataque de insetos em sementes apenas na testemunha com 23% do total (n = 100) e os resultados foram estatisticamente significativos (F = 31,263; p 0,001). Houve diferenças significativas apenas entre a altura das plântulas nos tratamentos T1 e T2 e a testemunha (F = 15,090; p 0,001). A principal praga identificada atacando as sementes foi Heilipus odoratus (Coleoptera: Curculionidae). Recomenda-se, portanto, a concentração de 0,09 mg de acetamiprid e fipronil distribuídos em sachês nas sementeiras e no transplantio para diminuir o ataque de pragas em sementes e mudas de pau-rosa em viveiros.
ABSTRACT
The goal of the present study was to evaluate the comparative efficacy of two topical formulations containing 10% fipronil on the control of Ctenocephalides felis felis on cats. The trial was performed at the Laboratory of Experimental Chemotherapy in Veterinary Parasitology from the Department of Animal Parasitology of the Institute of Veterinary of the Universidade Federal Rural do Rio de Janeiro. Eighteen mixed-breed cats were divided in three groups of six animals each. One group remained without treatment (control). The other groups received as treatment the two topical formulations, a commercial reference and the novel one, both containing 10% fipronil. Treated animals received 0.5 mL of product along their cervical region. Cats were infested on days - 2, +5, +12, +19, +26 and +33. Evaluations were made using the "comb test". The first one was undertaken 4 days after the initial infestation (day +2), and others 48 hours after following infestations (days +7, +14, +21, +28 and + 35). Both tested formulations had satisfactory efficacy until day + 35. No differences were observed comparing the efficacy levels between both formulations troughout the experimental period. The novel topical 10% fipronil formulation presented desirable efficacy on the control of C. f. felis on cats.
No presente trabalho, foram avaliadas, comparativamente, duas formulações comerciais tópicas, contendo 10% de fipronil, para o controle da pulga Ctenocephalides felis felis em gatos. O experimento foi realizado no Laboratório de Quimioterapia Experimental em Parasitologia Veterinária do Departamento de Parasitologia Animal, Instituto de Veterinária, da Universidade Federal Rural do Rio de Janeiro. Foram empregados 18 gatos, sem raça definida, divididos em três grupos de seis. Um grupo permaneceu sem tratamento (controle), e os demais foram medicados com uma formulação referência do mercado veterinário ou com uma nova formulação em teste. Os animais tratados receberam 0,5 mL do produto ao longo da região dorso-cervical e foram infestados nos dias - 2, +5, +12, +19, +26 e +33. A primeira avaliação foi realizada quatro dias após a primeira infestação e, as demais, 48 horas após cada infestação, por meio do comb test. Ambas as formulações testadas foram eficazes até o dia +35 após o tratamento, não havendo diferenças entre seus níveis de eficácia ao longo do período experimental. A nova formulação, contendo fipronil a 10%, apresentou a eficácia desejada no controle de C. f. felis em gatos.