Advances in the effects of pyrethroid exposure on child development / 国际儿科学杂志

Pyrethroids, a broad class of synthetic organic insecticides applied in daily life, are highly toxic in the water environment and can cause organisms to develop symptoms of neurotoxicity.Environmental exposure has become one of the important factors explored during child growth and development in recent years, and the exposure of pyrethroids in the environment has gradually increased, making their effects on child growth and development also highly valued.A large number of studies at home and abroad have found that pyrethroids have effects on multi system development: exposure during pregnancy can lead to intrauterine growth restriction, malformations, etc.Postnatal exposure can lead to cognitive retardation, abnormal pubertal development, and may also increase the risk of allergic diseases, wheeze, cough, and acute lymphoblastic leukemia.This article provides a review of the effects of pyrethroid exposure on growth and developmental processes in children.

A case of poisoning caused by intramuscular injection of esfenvalerate / 中华劳动卫生职业病杂志

Esfenvalerate is a kind of commonly used highly effective pyrethroid insecticide. It is common for people who are poisoned by contact or misuse, but rarely reported for people who are poisoned by intramuscular injection. This paper reports a case of intramuscular injection of esfenvalerate in the Department of Infection, West China Hospital of Sichuan University in November 2021. The patient was intramuscularly injected with about 20 ml of esfenvalerate, inducing the sense of swelling and tingling, degeneration and necrosis of striated muscle tissue at the injection site, also liver function damage and other manifestations. The patient was discharged from hospital after rehydration, accelerating poison metabolism, anti-infection, liver protection and local puncture.

Genetic diversity and Kdr mutations of natural Aedes (Stegomyia) aegypti (Diptera: Culicidae) populations of Brazil

ABSTRACT Aedes (Stegomyia) aegypti is an important vector of dengue, yellow fever, chikungunya and Zika virus. It is well known that resistance monitoring and genetic diversity data help designing the vector control programs. This study aimed to evaluate resistance to pyrethroids (PYs) through the frequency of kdr mutations Val1016IIe and F1534C, and the genetic variation of the mitochondrial gene ND4 in six natural populations of A. aegypti from Paraná - Brazil. Adults were obtained from eggs collected from Alvorada do Sul, Marilena, Maringá, Nova Londrina, Paranavaí and São Carlos do Ivaí. From these adults, 345 were used to identify the 1016 and 1534 sites, and 120 were used to perform the ND4 gene analysis. The studied populations from Paraná showed PYs resistance, low gene flow and genetic diversity. Additionally, a relationship was observed among the haplotypes of populations from the Amazon and Southeastern Brazil, Peru, Mexico, and North America.

Simultaneous quantification of pyrethroid metabolites in urine of non-toilet-trained children in Japan

BACKGROUND@#Pyrethroid (PYR) insecticides are widely used for controlling various pests. There are two types that differ in terms of usage: agricultural-purpose PYR (agriculture-PYR) and hygiene purpose PYR (hygiene-PYRs). Few studies exist on the exposure to these chemicals in small children. In this study, we conducted biomonitoring of urinary pyrethroid metabolites in 1.5-year-old children throughout the year.@*METHODS@#Study subjects were 1075 children participating in an Aichi regional sub-cohort of the Japan Environment and Children's Study as of 18-month health check-up. The concentrations of four specific hygiene-PYR metabolites including 2,3,5,6-tetrafluoro-1,4-benzenedimethanol (HOCH2-FB-Al), and five common metabolites of hygiene- and agriculture-PYRs including 3-phenoxybenzoic acid (3PBA) and cis- and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane-1-carboxylic acid (DCCA), were measured in urine samples extracted from soiled diapers using a triple quadrupole gas chromatograph-mass spectrometer.@*RESULTS@#The highest detection frequencies were for 3PBA, followed by DCCA, 1R-trans-chrysanthemum dicarboxylic acid, and HOCH2-FB-Al. Among the six metabolites, urinary concentrations were seasonally varied. However, this variation was not observed in the most studied PYR metabolite, 3PBA. Spearman's correlation analysis demonstrated a significant positive correlation between FB-Al and DCCA (r = 0.56) and HOCH2-FB-Al and 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl alcohol (r = 0.60).@*CONCLUSIONS@#This biomonitoring survey found widespread and seasonally specific exposure to multiple hygiene- and agriculture-PYRs in 1.5-year-old Japanese children.

Research progress on detection methods of pyrethroid insecticide residues in human biomaterials / 环境与职业医学

In recent years, due to the wide use of pyrethroid insecticides, the impact of pyrethroid insecticides on human health cannot be ignored. Therefore, how to detect pyrethroid insecticide residues in human body accurately and efficiently has become a research hotspot. However, it is difficult to detect pyrethroid insecticides because of its low residues and fast metabolism. Our article reviewed research on the detection of pyrethroid pesticide residues in human biomaterials in recent years, listed various pretreatment methods and detection methods of different biomaterials in detail, as well as summarized reported limits of detection, limits of quantitation, and recoveries of different methods. Finally, we prospected further development in detection methods of pyrethroid pesticide residues in human biomaterials.

Bioaccumulation of Pyrethroid in Parasite Wenyonia acuminata (Cestoda: Caryophyllaeidae) and Host fish Synodontis clarias (Linnaeus, 1758) from Lekki Lagoon, Lagos Nigeria / Bioacumulação de piretroide no parasita Wenyonia acuminata (Cestoda: Caryophyllaeidae) e peixe hospedeiro Synodontis clarias (Linnaeus, 1758) da lagoa de Lekki, Lagos, Nigéria

Abstract This study was aimed at determining the concentration of pyrethroid in the surface water, sediment, Weyonia acuminata and Synodontis clarias fish in Lekki lagoon, Lagos, Nigeria. In-situ physicochemical analysis of the surface water was conducted using a calibrated handheld multi-parameter probe (Horiba Checker Model U-10). Intestinal samples from infected and uninfected fish were analyzed for pyrethroid concentrations, microbial colonization, proteins (PRO), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), malonaldehyde (MDA) and glutathione peroxidase (GPx). The histopathology of infected and uninfected intestinal tissues were analyzed using Haematoxylin and Eosin (H&E) stains and examined under a binocular light microscope (Model 230485). A total of 39 out of 98 S. clarias fish were infected with cestode parasite, Wenyonia acuminate, amounting to 39% parasite prevalence. Among the tested pyrethroids, Cyfluthrin and Alpha -cypermethrin had significant sorption of 1.62 and 3.27 respectively from the aqueous phase to the bottom sediment of the lagoon. Pyrethroid concentration was in the order of sediment > parasite> water > intestine> liver. The cholesterol, triglycerides, and LDL (low density lipids) in the parasite were higher than in the host fish (p<0.05). On the other hand, the fish hepatic protein, high density lipids (HDL) and glucose were higher than the levels in the parasites (p<0.05). There was a high prevalence of gut microbes (30 - 40%), which include Salmonella sp, Escherichia coli, Pseudomonas sp and Bacillus sp among individuals infected with gut Cestodes, Wenyonia sp compared with uninfected individual which had higher gut Staphylococcus sp., Klebsiella sp., and Proteus sp. (10- 40%). among the congeners of pyrethroids analyzed, Cyfluthrin > Alpha-Cyermethrin had significant sorption on the sediment, however unlike a benthopelagic fish, no pyrethroid was accumulated in the S. clarias from the sediment. The fish however accumulated Alpha-Cypermethrin from the aqueous phase. The parasite on the other hand accumulated Bathroid significantly from the surface water and bottom sediment which may be linked to the higher stress levels observed in the parasite than the host fish. The parasite in turn inflicted histological alterations on the host intestine, marked by moderate inflammation of mucosa, alteration of the villi microstructure, moderate stunting of the villous structure and moderate fibrosis of villous structure. The study demonstrated the efficiency of histopathological and microbial analysis in biomonitoring studies enteric parasites and early detection of pyrethroid toxicity respectively compared to bioaccumulation analysis.

Resumo Este estudo teve como objetivo determinar a concentração de piretroide nos peixes de águas superficiais, sedimentos, Wenyonia acuminata e Synodontis clarias na lagoa de Lekki, Lagos, Nigéria. A análise físico-química in situ da água de superfície foi realizada usando uma sonda multiparâmetro manual calibrada (Horiba Checker Modelo U-10). Amostras intestinais de peixes infectados e não infectados foram analisadas quanto a concentrações de piretroides, colonização microbiana, proteínas (PRO), superóxido dismutase (SOD), catalase (CAT), glutationa reduzida (GSH), malonaldeído (MDA) e glutationa peroxidase (GPx). A histopatologia dos tecidos intestinais infectados e não infectados foi analisada usando manchas de Hematoxilina e Eosina (H&E) e examinada sob um microscópio de luz binocular (Modelo 230485). Um total de 39 dos 98 peixes de S. clarias foi infectado com o parasita cestoide Wenyonia acuminata, totalizando 39% de prevalência do parasita. Entre os piretroides testados, ciflutrina e alfa-cipermetrina tiveram sorção significativa de 1,62 e 3,27, respectivamente, da fase aquosa ao sedimento de fundo da lagoa. A concentração de piretroides estava na ordem de sedimentos > parasita > água > intestino > fígado. O colesterol, os triglicerídeos e o LDL (lipídios de baixa densidade) no parasita foram maiores que no peixe hospedeiro (p < 0,05). Por outro lado, a proteína hepática dos peixes, os lipídios de alta densidade (HDL) e a glicose foram superiores aos níveis nos parasitas (p < 0,05). Houve uma alta prevalência de micróbios intestinais (30-40%), incluindo Salmonella sp., Escherichia coli, Pseudomonas sp. e Bacillus sp. entre indivíduos infectados no intestino com o parasita cestoide Wenyonia sp. em comparação com indivíduos não infectados com Staphylococcus sp., Klebsiella intestinal sp. e Proteus sp. (10-40%). Entre os congêneres dos piretroides analisados, ciflutrina > alfa-cipermetrina teve sorção significativa no sedimento, porém, diferentemente de um peixe bentopelágico, nenhum piretroide foi acumulado no S. clarias do sedimento. No entanto, os peixes acumularam alfa-cipermetrina a partir da fase aquosa. O parasita, por outro lado, acumulou Bathroid significativamente da água superficial e do sedimento do fundo, o que pode estar relacionado aos níveis mais altos de estresse observados no parasita do que no peixe hospedeiro. O parasita, por sua vez, causou alterações histológicas no intestino hospedeiro, marcadas por inflamação moderada da mucosa, alteração da microestrutura das vilosidades, atrofia moderada da estrutura das vilosidades e fibrose moderada da estrutura das vilosidades. O estudo demonstrou a eficiência da análise histopatológica e microbiana nos estudos de biomonitoramento de parasitas entéricos e detecção precoce da toxicidade dos piretroides, respectivamente, em comparação à análise de bioacumulação.

Bioefficacy of mosquito mat vaporizers and associated metabolic detoxication mechanisms in Aedes aegypti (Linnaeus) in Selangor, Malaysia: A statewide assessment

@#This study aims to examine the efficacy of mosquito mat vaporizers on Aedes aegypti and their associated metabolic detoxication mechanisms. For this purpose, Aedes aegypti (Linnaeus) was collected from nine districts in Selangor, Malaysia and tested with mosquito vaporizing mat bioassays. The same populations were also subjected to biochemical assays to investigate activities of detoxifying enzymes, namely non-specific esterase (EST), glutathione-S-transferase (GST) and mixed function oxidase (MFO). The efficacy of Ae. aegypti on the active ingredients tested in decreasing order were d- allethrin > dimefluthrin > prallethrin with PBO > prallethrin. The results further indicated significant enhancement mean levels of EST, GST and MFO in pyrethroid-resistant populations. The mortality rate of Ae. aegypti in response to pyrethroid active ingredients was associated with MFO activity, suggesting it is an important detoxification enzyme for the populations tested. In view of the presence of resistance against household insecticide products, pyrethroid efficacy on Ae. aegypti populations needs to be monitored closely to ensure the implementation of an effective vector control program in Malaysia.

Understanding Behavioural Temperament of Phlebotomus argentipes Under the Influence of DDT-IRS Versus SP-IRS for Scoping New Approaches for Maximum Control Over the VL-Vector Population in Bihar

Background:After the decades of Dichlorodiphenyltrichloroethane (DDT) use, Phlebotomus argentipesreportedly developed resistance against it affecting every aspect of vector control at grass-root level. Although DDT based Indoor Residual Spray (IRS) has been replaced with Alphacypermethrine-a Synthetic Pyrethroid (SP) based insecticide, since 2016 butits successful implementation at the Visceral Leishmaniasis (VL) endemic regime of Bihar doesn’t cause much effect upon VL vector density. Furthermore, the outcomes of existing operational research works, it Original ResearchArticle had been observed that VL vectors are continuously changing its behavior under the pressure of insecticides. Methods: For validating the hypothesis, present study has been carried out at Vaishali and Patna being highly and semi-endemic sites respectively for quantifying the oriental behavior among VL vectors persuaded by the IRS and enforce them to remain alive and get trapped in light trap even after changed chemical composition of IRS i.e., SP-IRS from routine DDT-IRS. Results:Following results, a significant reduction in sand fly density (i.e., 33.09% and 29.16%) was observed for outdoor and indoor caught sand flies, collected with light trap and aspirator respectively. Significant higher no. of sand fly collection in terms of per light traps per night was recorded from the outdoor sites than thosefrom indoor habitat for each village of Vaishali and Saran district of Bihar. Higher no. of male sand flies than to that of female ones were collected from outdoor sites and only unfed female sand flies (i.e., 100%) were caught following SP-IRS from each study villages of Vaishali and Saran districts of Bihar.Conclusions:The results of higher no. of sand flies collection from the outdoor sites as compared with the indoor habitat validate the hypothesis of gradual shifting of habitat of VL vectors from endophilic to exophilic which is undoubtedly followed due to the fact of developed resistance among them against chemical constituent of IRS. Results provide very useful information about the sand fly dynamics under the impact of IRS and accordingly, advocates the combined approach of IRS along with insecticidal fogging together at a same time that could be an effective dividend for maximum VL vector control along for negotiating VL cases at par for longer duration during the maintenance phase at the VL foci.

Neurohistological Changes in the Spinal Cord of Albino Rats after Inhalational Exposure to Pyrethroid Based Mosquito Repellent

Background: The use of liquid vaporizers as residential insecticides to control the problem of mosquito bites and to prevent adult, newborns and children from deadly vector borne diseases like Malaria, Dengue and chikungunya etc. is ever increasing. These products contain pyrethroid and emit parallethrin vapours when put to use at home. There are numerous side effects of these vapours like allergic sinusitis, difficulty in respiration, sleep disturbance, giddiness, headache, body ache and lethargy but the market for these product decides the outcome of all the research concerned with its safety. Histological studies can establish their toxic effects on Spinal Cord, cervical and lumbar enlargements in the White and Grey matter that forms structural continuity with the CNS. Accordingly the present  study was planned to assess the safety of  pyrethroid based mosquito repellent inhalational use and the histological insult to the spinal cord of  Albino rats. Methods: Total of twenty albino rats were equally divided into control and experimental group. The experimental group was exposed  to 3.2% w/v prallethrin vapours for total of 12 hours per day for 180 days. The control group rats was exposed to identical situation but without any exposure. The albino rats  were sacrificed after the study period of exposure of 180 days. Spinal cord dissected., tissue processed, sectioned and stained with  haematoxylin, eosin and thionin. Results: Grey matter of the spinal cord at cervical and lumbar enlargement showed numerous vacuoles with lightly stained cell body of neurons and Nissl’s dissolution with occasional inflammatory cells. Conclusions: Neurohistological study, inhalational route, neurotoxicity, adult albino rats, prallethrin vapours, spinal cord.

Research progress on pesticide residues in Chinese medicinal materials and pesticide removal methods / 中草药

Recently, with the increasing demand of Chinese medicinal materials production, the use of pesticides during cultivation has also increased, which caused seriously pesticide residues in Chinese medicinal materials. At present, pesticide residues in Chinese medicinal materials have resulted in severe impacts on quality, safe usage and export of Chinese medicinal materials. This article reviews the research progress on three major pesticide residues in Chinese medicinal materials over the past ten years, and the data showed that the residual situation of organochlorine pesticides, organophosphorus pesticides and pyrethroid pesticides in Chinese medicinal materials are still serious, but the research status is not optimistic. Meanwhile, the statistical result from current feasible pesticide removal methods showed that the usage frequency of physical method is higher than that of chemical removal method, in addition, biological methods have not yet popularized in Chinese medicinal materials. Furthermore, different pesticide removal methods were evaluated according to the characteristics of pesticide residues in Chinese medicinal materials and the particularity of each method. As a result, a pesticide removal method by using genetic engineering technology that is green, efficient and environmental friendly was recommended, which won’t destroy the active ingredients of Chinese medicinal materials. The feasible measures to improve pesticide residues in Chinese medicinal materials are prospected in this article.

Pyrethroid Exposure and Related Factors among Pregnant Women in the First Trimester in Rural Yunnan Province, China / 昆明医科大学学报

Objective To investigate the level and relevant factors of pyrethroid pesticide exposure among pregnant women during the first trimester in rural areas of Yunnan province,and to provide basic data for further study and provide a basis for the formulation of intervention measures to reduce exposure.Methods According to the birth cohort of rural Yunnan built in 2014, pregnant women in the first trimester were recruited in two townships of an agricultural county who were confirmed pregnant and continued pregnancy in antenatal clinics. The concentration of the metabolites of the pesticides in the urine of women was determined by super high performance liquid chromatography and the contact status of pyrethroid pesticides was analyzed using a questionnaire survey. Results A total of 419 women in the first trimester were surveyed and 94.51% of women detected at least one of the pyrethroid metabolites, among which the detection rates of 3－Phenoxybenzoic acid (3－PBA), cis－/trans－3－ (2, 2－Dichloroethenyl)－2, 2－dimethyl－cyclopropanecarboxylate (cis－/trans－DCCA) and 4－fluoro－3－phenoxybenzoic acid (4－F－3－PBA) were 79.47%, 62.05% and 24.58%,and the median concentrations were 3.53 ng/mL, 14.80 ng/m L and less than the minimum detection limit 0.4 ng/m L.Only 12 people (2.95%) reported that they had exposure to pesticides.Self－reported exposure rate was not consistent with the actual exposure rate.Multivariate linear regression analysis showed that the season was a factor affecting the level of three metabolites in women in the first trimester. Higher lever was found in women in spring (t=2.147,P=0.032), summer (t=2.144,P=0.035) and winter (t=2.453,P=0.015) compared to those in autumn.Conclusion Pyrethroid pesticides were widely exposed in the pregnant women in rural areas of Yunnan province. Some women have higher exposure level, which is related to the season.

Ocimum basilicum essential oil combined with deltamethrin to improve the management of Spodoptera frugiperda / Óleo essencial de Ocimum basilicum associado à deltametrina no manejo de Spodoptera frugiperda

ABSTRACT For an important and expensive crop such as corn, the resistance of Spodoptera frugiperda J.E. Smith to various pesticides has led to research throughout the world for a potential insecticide from a natural source. For the management of pest resistance, natural compounds associated with synthetic insecticides can be a promising tool because they can reduce the application of the synthetics molecules while maintaining their effectiveness and promoting the control of the pests. Linalool is a potential insecticide that is easily obtained because it is found in high concentrations in the essential oil of Ocimum basilicum L. Therefore, the present study aimed to evaluate the toxicity of this essential oil and its combination with deltamethrin to control S. frugiperda. Through dose response assays, the acute toxicities (LD50) of the essential oil and deltamethrin were estimated. Additionally, the combination of these materials was also assessed, attaining a reduction of 80% of the LD50 of deltamethrin while obtaining the same result as when the pyrethroid was administered alone. From these results, it is expected that the combination of natural compounds and synthetic insecticides will be a promising practice, helping to manage resistance while reducing the environmental impact of toxic compounds.

RESUMO Para uma cultura importante e expressiva como o milho, a resistência de Spodoptera frugiperda J.E. Smith a vários inseticidas atraiu a atenção no mundo para pesquisar o potencial inseticida de compostos naturais. Para o manejo da resistência, os compostos naturais associados a inseticidas sintéticos podem ser uma ferramenta promissória por reduzirem a aplicação das moléculas sintéticas para que não percam sua eficácia, além de promover o controle das pragas. O linalol é um terpenoide considerado como inseticida potencial, pode ser facilmente obtido naturalmente uma vez que é encontrado em alta concentração no óleo essencial de Ocimum basilicum. Portanto, o presente estudo teve como objetivo avaliar a toxicidade deste óleo essencial e sua combinação com deltametrina no controle de Spodoptera frugiperda. Através do ensaio de dose-resposta, foi estimada a toxicidade aguda (DL50) do óleo essencial e da deltametrina. Adicionalmente, foi também avaliada a combinação entre ambos, alcançando uma redução de 80% da DL50 de deltametrina para se obter o mesmo resultado quando o piretroide foi administrado sozinho. A partir dos nossos resultados, espera-se que uma combinação de uso de compostos naturais e inseticidas sintéticos possa ser uma prática promissora, auxiliando no manejo da resistência de pragas e principalmente reduzindo os impactos ambientais de compostos tóxicos.

Acute Toxicity of the Insecticide Cypermethrin (CYPERMON ® 20 EC) on Four Species of Colombian Anurans / Toxicidad aguda del insecticida cipermetrina (cypermon ® 20 ec) en cuatro especies de anuros colombianos

RESUMEN El insecticida cipermetrina (CY) es usado en la agricultura para el control de plagas; sin embargo, por su acción neurotóxica puede afectar organismos no blanco como los anuros. El objetivo del trabajo fue determinar la toxicidad (concentración letal media: CL50, y algunos efectos subletales: retrasos en el desarrollo, capacidad de natación y longitud total de las larvas) del insecticida CY (Cypermon® 20EC) expuesto durante 96 horas en embriones y renacuajos de cuatro especies de anuros bajo pruebas de laboratorio y microcosmos. Los embriones de Rhinella humboldti fueron los más sensibles en condiciones de laboratorio (CL50= 6,27 mg/L) y Boana xerophylla en microcosmos (CL50= 88,32 mg/ha), mientras que los de Engystomops pustulosus fueron los más resistentes (laboratorio: CL50= 1 1,80 mg/L; microcosmos: CL50= 1 12,37 mg/ha). Rhinella marina mostró una sensibilidad intermedia. En los renacuajos no fue posible calcular los valores CL50 debido a la alta mortalidad registrada en las concentraciones experimentales en laboratorio y microcosmos, las cuales fueron 40 y 122 veces menores al valor de aplicación del insecticida (500 mg/L y 1,52 mg/ha, respectivamente). Por otra parte, se encontró una reducción significante en la longitud total y la capacidad de natación de las larvas obtenidas de los embriones expuestos a la CY, pero no en el tiempo de desarrollo. En conclusión, la exposición a la cipermetrina provocó una letalidad alta en los renacuajos y efectos subletales en estadíos tempranos del desarrollo, por lo que a las concentraciones recomendadas de aplicación, este insecticida es tóxico para las especies de estudio.

ABSTRACT The cypermethrin (CY) insecticide is used in agriculture for the control of pests; however, due to its neurological action can affect non-target organisms such as anurans. The aim of this study was to evaluate the toxicity (median lethal concentration: LC50, and some sublethal effects: developmental delays, swimming performance and total length of larvae) of the insecticide CY (Cypermon® 20EC) exposed during 96 hours to embryos and tadpoles of four anuran species under laboratory and microcosm tests. The embryos of Rhinella humboldti were the most sensitive in laboratory conditions (LC50= 6.27 mg/L) and Boana xerophylla in microcosms (LC50= 88.32 mg/ha), whereas Engystomops pustulosus (laboratory: LC50= 1 1.80 mg/L, microcosms: LC50= 1 12.37 mg/ha) was the most resistant species. Rhinella marina showed an intermediate sensitivity. It was not possible to calculate the tadpole LC50 values due to the high mortality recorded in the experimental concentrations, both in laboratory and microcosms, which were 40 and 122 times lower than the value suggested for the application of the insecticide in field (500 mg/L and 1.52 mg/ha, respectively). On the other hand, it was found a significant decreasing in the total length and swimming performance of the larvae obtained from the embryos exposed to CY, but not in the embryonic developmental time. In conclusion, the exposure to the cypermethrin produced a high tadpole lethality and sublethal effects on developing embryos; therefore, under the recommended concentrations of field exposition, this insecticide is toxic for the study species.

First investigation of deltamethrin pyrethroid susceptibility and resistance status of Anopheles labranchiae (Falleroni, 1926), potential malaria vector in Tunisia

Objective:To evaluate the deltamethrin pyrethroid insecticides against Anopheles labranchiae,potential malaria vector in Tunisia.Methods:Six field populations of Anopheles labranchiae mosquitoes were collected from six localities in Northern and Central Tunisia between October and November 2016.Different bioassays were performed to estimate the level of resistance in each collected population.Two synergists were used to estimate the involvement of detoxification enzymes in insecticide resistance.Results:All studied strains were resistant and the RRs0 ranged from 12.5 in sample #1 to 72.5 in sample #6.Synergist tests using piperonyl butoxide indicated the involvement of monoxygenases enzymes in the recorded resistance.In contrast,the increase of deltamethrin mortality was not significant in presence of S,S,sributyl phosphorothioate (0.8 ＜ SR ＜ 1.2),suggesting no role of esterases (and/or GST) in the resistance phenotype.The correlation recorded between mortality due to DDT and the LC50 of deltamethrin insecticide indicated an insensitive sodium channel affected by Kdr mutation (Spearman rank correlation,r =-0.59,P ＜ 0.01).Conclusions:These results should be considered in the current mosquitoes control programs in Tunisia.The use of pesticides and insecticides by both agricultural and public health departments in Tunisia should be more rational to reduce the development of resistance in populations.Different insecticide applications should be implemented alternately.

First investigation of deltamethrin pyrethroid susceptibility and resistance status of Anopheles labranchiae (Falleroni, 1926), potential malaria vector in Tunisia

Objective To evaluate the deltamethrin pyrethroid insecticides against Anopheles labranchiae, potential malaria vector in Tunisia. Methods Six field populations of Anopheles labranchiae mosquitoes were collected from six localities in Northern and Central Tunisia between October and November 2016. Different bioassays were performed to estimate the level of resistance in each collected population. Two synergists were used to estimate the involvement of detoxification enzymes in insecticide resistance. Results All studied strains were resistant and the RR

Diversity of insects under the effect of Bt maize and insecticides / Diversidade de insetos sob a influência do milho Bt e inseticidas

The genetically modified maize to control some caterpillars has been widely used in Brazil. The effect of Bt maize and insecticides was evaluated on the diversity of insects (species richness and abundance), based on the insect community, functional groups and species. This study was conducted in genetically modified maize MON810, which expresses the Cry1Ab protein from Bacillus thuringiensis Berliner, and conventional maize with and without insecticide sprays (lufenuron and lambda-cyhalothrin) under field conditions in Ponta Grossa (Paraná state, Brazil). Insect samplings were performed by using pitfall trap, water tray trap and yellow sticky card. A total of 253,454 insects were collected, distributed among nine orders, 82 families and 241 species. No differences were observed in the insect community based on the richness, diversity and evenness indices. Predators and pollinators were more abundant in genetically modified maize. Parasitoids, detritivores, sap-sucking herbivores and chewing herbivores were more abundant in conventional maize with insecticide sprays. Significant differences were found for the species Colopterus sp., Colaspis occidentalis (L.) and Nusalala tessellata (Gerstaecker) which were most abundant in Bt maize, and Dalbulus maidis and Condylostylus sp.2 in conventional maize.(AU)

O milho geneticamente modificado visando ao controle de lagartas tem sido amplamente utilizado no Brasil. Em estudo de campo realizado em Ponta Grossa (Paraná, Brasil), compararam-se, com base na diversidade (riqueza de espécies e abundância), os efeitos do milho Bt e do controle químico sobre a comunidade de insetos, grupos funcionais e espécies. A comunidade de insetos foi amostrada no milho geneticamente modificado MON810, que expressa a proteína Cry1Ab de Bacillus thuringiensis Berliner, e no milho convencional com e sem a aplicação de inseticidas (lufenuron e lambda-cialotrina). As amostragens foram realizadas por meio da coleta de insetos utilizando-se armadilha de queda, bandeja-d'água e cartão adesivo. Foram coletados 253.454 insetos, distribuídos em nove ordens, 82 famílias e 241 espécies. Não foram observadas diferenças na comunidade de insetos para os índices de riqueza, diversidade e equitabilidade nos tratamentos avaliados. Predadores e polinizadores foram mais abundantes no milho geneticamente modificado, e parasitoides, decompositores, sugadores e mastigadores, no milho convencional com inseticida. Diferenças significativas foram detectadas para as espécies Colopterus sp., Colaspis occidentalis (L.) e Nusalala tessellata (Gerstaecker), mais abundantes no milho Bt, e Dalbulus maidis e Condylostylus sp.2, mais abundantes no milho convencional.(AU)

Bioaccumulation of Pyrethroid in Parasite Wenyonia acuminata (Cestoda: Caryophyllaeidae) and Host fish Synodontis clarias (Linnaeus, 1758) from Lekki Lagoon, Lagos Nigeria

Abstract This study was aimed at determining the concentration of pyrethroid in the surface water, sediment, Weyonia acuminata and Synodontis clarias fish in Lekki lagoon, Lagos, Nigeria. In-situ physicochemical analysis of the surface water was conducted using a calibrated handheld multi-parameter probe (Horiba Checker Model U-10). Intestinal samples from infected and uninfected fish were analyzed for pyrethroid concentrations, microbial colonization, proteins (PRO), superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), malonaldehyde (MDA) and glutathione peroxidase (GPx). The histopathology of infected and uninfected intestinal tissues were analyzed using Haematoxylin and Eosin (H&E) stains and examined under a binocular light microscope (Model 230485). A total of 39 out of 98 S. clarias fish were infected with cestode parasite, Wenyonia acuminate, amounting to 39% parasite prevalence. Among the tested pyrethroids, Cyfluthrin and Alpha cypermethrin had significant sorption of 1.62 and 3.27 respectively from the aqueous phase to the bottom sediment of the lagoon. Pyrethroid concentration was in the order of sediment > parasite> water > intestine> liver. The cholesterol, triglycerides, and LDL (low density lipids) in the parasite were higher than in the host fish (p 0.05). On the other hand, the fish hepatic protein, high density lipids (HDL) and glucose were higher than the levels in the parasites (p 0.05). There was a high prevalence of gut microbes (30 - 40%), which include Salmonella sp, Escherichia coli, Pseudomonas sp and Bacillus sp among individuals infected with gut Cestodes, Wenyonia sp compared with uninfected individual which had higher gut Staphylococcus sp., Klebsiella sp., and Proteus sp. (10- 40%). among the congeners of pyrethroids analyzed, Cyfluthrin > Alpha-Cyermethrin had significant sorption on the sediment, however unlike a benthopelagic fish, no pyrethroid was accumulated in the S. clarias from the sediment. The fish however accumulated Alpha-Cypermethrin from the aqueous phase. The parasite on the other hand accumulated Bathroid significantly from the surface water and bottom sediment which may be linked to the higher stress levels observed in the parasite than the host fish. The parasite in turn inflicted histological alterations on the host intestine, marked by moderate inflammation of mucosa, alteration of the villi microstructure, moderate stunting of the villous structure and moderate fibrosis of villous structure. The study demonstrated the efficiency of histopathological and microbial analysis in biomonitoring studies enteric parasites and early detection of pyrethroid toxicity respectively compared to bioaccumulation analysis.

Resumo Este estudo teve como objetivo determinar a concentração de piretroide nos peixes de águas superficiais, sedimentos, Wenyonia acuminata e Synodontis clarias na lagoa de Lekki, Lagos, Nigéria. A análise físico-química in situ da água de superfície foi realizada usando uma sonda multiparâmetro manual calibrada (Horiba Checker Modelo U-10). Amostras intestinais de peixes infectados e não infectados foram analisadas quanto a concentrações de piretroides, colonização microbiana, proteínas (PRO), superóxido dismutase (SOD), catalase (CAT), glutationa reduzida (GSH), malonaldeído (MDA) e glutationa peroxidase (GPx). A histopatologia dos tecidos intestinais infectados e não infectados foi analisada usando manchas de Hematoxilina e Eosina (H&E) e examinada sob um microscópio de luz binocular (Modelo 230485). Um total de 39 dos 98 peixes de S. clarias foi infectado com o parasita cestoide Wenyonia acuminata, totalizando 39% de prevalência do parasita. Entre os piretroides testados, ciflutrina e alfa-cipermetrina tiveram sorção significativa de 1,62 e 3,27, respectivamente, da fase aquosa ao sedimento de fundo da lagoa. A concentração de piretroides estava na ordem de sedimentos > parasita > água > intestino > fígado. O colesterol, os triglicerídeos e o LDL (lipídios de baixa densidade) no parasita foram maiores que no peixe hospedeiro (p 0,05). Por outro lado, a proteína hepática dos peixes, os lipídios de alta densidade (HDL) e a glicose foram superiores aos níveis nos parasitas (p 0,05). Houve uma alta prevalência de micróbios intestinais (30-40%), incluindo Salmonella sp., Escherichia coli, Pseudomonas sp. e Bacillus sp. entre indivíduos infectados no intestino com o parasita cestoide Wenyonia sp. em comparação com indivíduos não infectados com Staphylococcus sp., Klebsiella intestinal sp. e Proteus sp. (10-40%). Entre os congêneres dos piretroides analisados, ciflutrina > alfa-cipermetrina teve sorção significativa no sedimento, porém, diferentemente de um peixe bentopelágico, nenhum piretroide foi acumulado no S. clarias do sedimento. No entanto, os peixes acumularam alfa-cipermetrina a partir da fase aquosa. O parasita, por outro lado, acumulou Bathroid significativamente da água superficial e do sedimento do fundo, o que pode estar relacionado aos níveis mais altos de estresse observados no parasita do que no peixe hospedeiro. O parasita, por sua vez, causou alterações histológicas no intestino hospedeiro, marcadas por inflamação moderada da mucosa, alteração da microestrutura das vilosidades, atrofia moderada da estrutura das vilosidades e fibrose moderada da estrutura das vilosidades. O estudo demonstrou a eficiência da análise histopatológica e microbiana nos estudos de biomonitoramento de parasitas entéricos e detecção precoce da toxicidade dos piretroides, respectivamente, em comparação à análise de bioacumulação.

Estado de la resistencia a insecticidas en Aedes aegypti (Diptera: Culicidae) del municipio Pinar del Río / Situation of resistance to insecticides in Aedes aegypti (Diptera: Culicidae) from Pinar del Rio municipality

Introducción: el programa de control de Aedes aegypti (Linnaeus) (Diptera: Culicidae) en Cuba utiliza temefos como larvicida y piretroides como adulticidas, aunque el organofosforado clorpirifos ha sido utilizado esporádicamente. Conocer el nivel de resistencia a estos insecticidas es esencial para lograr un control efectivo de esta especie. Objetivo: determinar el nivel de resistencia a insecticidas en su grado técnico y en sus formulaciones comerciales en Ae. aegypti de Pinar del Río. Métodos: una cepa de Ae. aegypti del Área de Salud Raúl Sánchez, Pinar del Río, fue evaluada a través de los bioensayos de la Organización Mundial de la Salud para determinar la susceptibilidad en larvas al organofosforado temefos en su formulación técnica. Se evaluaron además tres formulaciones granuladas de temefos (Abatex-G1, Biolarv G-1 y Temefar G-1). En el estado adulto se determinó el nivel de susceptibilidad a los insecticidas piretroides: cipermetrina, deltametrina, lambdacialotrina y al organofosforado clorpirifos, en su formulación técnica. Además se evaluaron algunos en su formulación comercial: Galgotrin 25 EC (cipermetrina), Aqua K-Otrina 2 EW (deltametrina) y Clorcide 44 EC (clorpirifos). Resultados: en larvas, se encontró alta resistencia a temefos, en su formulación técnica, y con los productos en su formulación comercial, se observó una efectividad del 100 por ciento, con recambio diario de agua, de hasta 20 días para Temefar G1, 18 días para Biolarv G1 y 12 días para Abatex G1. En los ensayos de adultos, la cepa resultó susceptible a cipermetrina, deltametrina y clorpirifos, y resistente a lambdacialotrina. Con respecto a las tres formulaciones comerciales evaluadas, solo se observó resistencia a Aqua K-Otrina 2 EW. Conclusiones: el uso de estrategias de control integrado de Ae. aegypti se hace necesario para disminuir la frecuencia de uso de temefos, y así recuperar la efectividad de este insecticida. Además, se evitaría la aparición de resistencia a productos adulticidas que aun mantienen su efectividad para el control efectivo de esta especie en la zona de estudio(AU)

Introduction: the control program of Aedes aegypti (Linnaeus) (Diptera: Culicidae) in Cuba uses temephos as larvicide and pyrethroids as adulticide although the organophosphorate chlorpyrifos has been barely used. The level of knowledge about resistance to insecticides is essential to effectively control this species. Objective: to determine the level of resistance to insecticides of Ae. aegypti from Pinar del Rio in its technical aspect and in commercial formulations. Methods: one Ae. aegypti strain from the health area Raul Sánchez in Pinar del Rio province was evaluated through the World Health Organization bioassays to determine susceptibility of larvae to temephos in its technical formulation. Additionally, three granulated formulations of temephos were evaluated (Abatex-G1, Biolarv G-1 and Temefar G-1). In the adult state, the level of susceptibility to pyrethroids called cypermethrin, deltamethrin, lambda cyhalothrine and to organophosphate chlorpyrifos in its technical formulation. Some of them were evaluated in its commercial formulation (Galgotrin 25 EC (cypermethrin), Aqua K-Otrina 2 EW (deltamethrin) and Clorcide 44 EC (chlorpyrifos). Results: it was found in larvae that the resistance to temephos was high in the technical formulation, but the commercial formulation showed an effectiveness rate of 100 percent., with daily change of water, up to 20 days for Temefar G1, 18 days for Biolarv G1 and 12 for Abatex G1. In the assays with adult vectors, the strain turned to be susceptible to cypermethrin, deltamethrin and chlorpyrifos and resistant to lambda cyhalothrin. Regarding the three evaluated commercial formulations, resistance to Aqua K-Otrina 2 EW was proved. Conclusions: the use of integrated control strategies for Ae. aegypti makes it necessary to reduce the frequency of use of temephos and to recover the effectiveness of this insecticide. Moreover, it will avoid the occurrence of resistance to adulticide products that are still effective for the control of this species in the study area(AU)

Association between urinary 3-phenoxybenzoic acid and body mass index in Korean adults: 1st Korean National Environmental Health Survey

BACKGROUND: According to US-EPA report, the use of pyrethrins and pyrethroids has increased during the past decade, and their area of use included not only in agricultural settings, but in commerce, and individual household. It is known that urinary 3-PBA, major metabolite of pyrethroid, have some associations with health effect in nervous and endocrine system, however, there’s no known evidence that urinary 3-PBA have associations with obesity. METHOD: We used data of 3671 participants aged above 19 from the Korean National Environmental Health Survey in 2009–2011. In our analysis, multivariate piece-wise regression and logistic regression analysis were used to investigate the association between urinary 3-PBA (3-Phenoxybenzoic Acid) and BMI. RESULT: Log-transformed level of urinary 3-PBA had significantly positive association with BMI at the low-level range of exposure (p < 0.0001), and opposite associations were observed at the high level exposure (p = 0.04) after adjusting covariates. In piece-wise regression analysis, the flexion point that changes direction of the associations was at around 4 ug/g creatinine of urinary 3-PBA. As quintiles based on concentration of urinary 3-PBA increased to Q4, the ORs for prevalence of overweight (BMI ≥ 23 kg/m2) were increased, and the OR of Q5 was lower than that of Q4 (OR = 1.810 for Q4; OR = 1.483 for Q5). In the analysis using obesity (BMI ≥ 25 kg/m2) as outcome variable, significant associations were observed between obesity and quintiles of 3-PBA, however, there were no differences between the OR of Q5 and that of Q4 (OR = 1.659 for Q4; OR = 1.666 for Q5). CONCLUSION: Our analysis suggested that low-level of pyrethroid exposure has positive association with BMI, however, there is an inverse relationship above the urinary 3-PBA level at 4 ug/g creatinine. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40557-015-0079-7) contains supplementary material, which is available to authorized users.

Evaluation of Acute toxicity of Lambda Cyhalothrin in Mus musculus L.

Lambda Cyhalothrin (LCT) is a type II synthetic pyrethroid widely used in agriculture, home pest control and protection of food stuff. Here, we evaluated its toxicity on biochemical parameters (Total protein, Acetyl cholinesterase, RNA and DNA) and liver histological alteration in mice after 24 h of oral administration @ 25, 50 and 75% of LD50 i.e., 26.49 mg/kg/body wt. Distilled water (DW) and Cyclophosphamide (CP @ 40 mg/kg/body wt.) were used as negative and positive control, respectively. LCT treated mice showed significant decrease in total protein (P <0.01), acetyl cholinesterase (P <0.001) and DNA (P <0.001) in a dose dependent manner. On the contrary, RNA content showed significant increase (P <0.01) at 50% of LD50 of LCT. Histological observations of the mice liver showed vascular congestion and hepatocyte degeneration with 6.63 mg/kg/body wt. of LCT; and accumulation of RBCs with sinusoid degeneration and wide necrotic area with pyknosis with 13.25 and 19.88 mg/kg/body wt., respectively. The results demonstrated LCT induced biochemical changes and hepatotoxicity in female mice.