azoxystrobin and iprodione

Azoxystrobin (AZO) and Iprodione (IPR) fungicides are extensively used worldwide, and therefore, contaminate all environmental compartments. The toxicity and the mechanisms by which they affected immune cells are complex and remain unknown. This study investigated the impact of AZO and IPR on the in vitro function of mice peritoneal macrophages including lysosomal enzyme activity and tumor necrosis factor (TNF)α and nitric oxide (NO) production in response to lipopolysaccharide (LPS) stimulation, the proliferation of mice splenocytes stimulated by concanavalin (Con)A and LPS, and the production of the Th1cytokine interferon-gamma (IFNγ) and the Th2 cytokine interleukin (IL)-4 and IL-10 by ConA-activated splenocytes. This is the first report indicating that AZO and IPR fungicides dose-dependently inhibited mice macrophage lysosomal enzyme activity and LPS-stimulated production of TNFα and NO. Mitogen-induced proliferation of mice splenocytes was also suppressed by AZO and IPR in a dose-dependent manner. More pronounced impact was observed on ConA-induced response. The production of IFNγ by ConA-stimulated splenocytes was dose-dependently inhibited; however, the production of IL-4 and IL-10 increased in the same conditions. These results suggested that AZO and IPR polarized Th1/Th2 cytokine balance towards Th2 response. Overall, marked immunosuppressive effects were observed for AZO. The immunomodulatory effects caused by AZO and IPR were partially reversed by the pharmacological antioxidant N-acetylcysteine (NAC), suggesting that both fungicides exerted their actions through, at least in part, oxidative stress-dependent mechanism. Collectively, our data showed that AZO and IPR fungicides exerted potent immunomodulatory effects in vitro with eventually strong consequences on immune response and immunologically based diseases.

Topics: Acetylcysteine; Aminoimidazole Carboxamide; Animals; Cell Proliferation; Cell Survival; Cells, Cultured; Cytokines; Dose-Response Relationship, Drug; Environmental Pollutants; Fungicides, Industrial; Hydantoins; Macrophages, Peritoneal; Male; Mice; Pyrimidines; Spleen; Strobilurins

Botrytis fruit rot, caused by Botrytis cinerea, is one of the most important strawberry diseases worldwide, and fungicide applications are often used to manage the disease in commercial production. Isolates of B. cinerea were collected from conventional and organic strawberry fields in four Brazilian States from 2013 to 2015 and their sensitivity to the main single-site mode-of action fungicides used in Brazil was tested. Resistance to azoxystrobin, iprodione, pyrimethanil, and thiophanate-methyl was found and values for effective concentration that inhibited mycelial growth by 50% were higher than 71.9, 1.2, 5.0, and 688 µg/ml, respectively, regardless the production system. Resistance to these fungicides was observed in 87.5, 76.6, 23.4, and 92.2% of isolates from conventional fields and 31.4, 22.9, 14.3, and 51.4% of isolates from organic fields, respectively. Moreover, frequencies of isolates with multiple fungicide resistance to the four active ingredients were 20.6 and 2.8% whereas 6.3 and 27.8% were sensitive to the four fungicides for conventional and organic areas, respectively. Molecular analyses of the cytochrome b, β-tubulin, and bos1 genes revealed the presence of G143A; E198A; and I365 N/S, Q369P, or N373S mutations, respectively, in resistant isolates of B. cinerea. Field rates of fungicides sprayed preventively to inoculated strawberry fruit failed to control disease caused by the respective resistant isolates.

Topics: Aminoimidazole Carboxamide; Botrytis; Brazil; Drug Resistance, Fungal; Fragaria; Fruit; Fungicides, Industrial; Hydantoins; Plant Diseases; Pyrimidines; Strobilurins; Thiophanate

Rhizoctonia is a major pathogen of potato causing substantial yield losses worldwide. Control of Rhizoctonia diseases is based predominantly on the application of fungicides. However, little is known about the fungicide response variability of different Rhizoctonia anastomosis groups associated with potato diseases in South Africa. A total of 131 Rhizoctonia isolates were obtained from potato growing regions of South Africa from 2012 to 2014 and evaluated for sensitivity to fungicides in vitro and in vivo. The fungicides comprised six chemical formulations and one bio-fungicide representing seven Fungicide Resistance Action Committee groups. All Rhizoctonia anastomosis groups were sensitive to tolclofos-methyl (EC

Topics: Aminoimidazole Carboxamide; Dioxoles; Fungicides, Industrial; Hydantoins; Microbial Sensitivity Tests; Phenylurea Compounds; Plant Diseases; Pyrimidines; Pyrroles; Rhizoctonia; Solanum tuberosum; South Africa; Species Specificity; Strobilurins

The aim of this study was to determine the behaviour of strobilurin and carbocyamides commonly used in chemical protection of lettuce depending on carefully selected effective microorganisms (EM) and yeast (Y). Additionally, the assessment of the chronic health risk during a 2-week experiment was performed. The statistical method for correlation of physico-chemical parameters and time of degradation for pesticides was applied. In this study, the concentration of azoxystrobin, boscalid, pyraclostrobin and iprodione using liquid chromatography-mass spectrometry (LC-MS/MS) in the matrix of lettuce plants was performed, and there was no case of concentration above maximum residues levels. Before harvest, four fungicides and their mixture with EM (1 % and 10 %) and/or yeast 5 % were applied. In our work, the mixtures of 1%EM + Y and 10%EM + Y both stimulated and inhibited the degradation of the tested active substances. Adding 10%EM to the test substances strongly inhibited the degradation of iprodione, and its concentration decreased by 30 %, and in the case of other test substances, the degradation was approximately 60 %. Moreover, the addition of yeast stimulated the distribution of pyraclostrobin and boscalid in lettuce leaves. The risk assessment for the pesticides ranged from 0.4 to 64.8 % on day 1, but after 14 days, it ranged from 0.0 to 20.9 % for children and adults, respectively. It indicated no risk of adverse effects following exposure to individual pesticides and their mixtures with EM and yeast.

Topics: Aminoimidazole Carboxamide; Aspergillus; Biphenyl Compounds; Carbamates; Chromatography, Liquid; Environmental Monitoring; Fungicides, Industrial; Humans; Hydantoins; Lactobacillales; Lactuca; Methacrylates; Mucor; Niacinamide; Penicillium; Pesticide Residues; Pesticides; Pyrazoles; Pyrimidines; Rhodobacteraceae; Risk Assessment; Saccharomyces cerevisiae; Streptomyces; Strobilurins; Tandem Mass Spectrometry

Pesticides residues in aquatic ecosystems are an environmental concern which requires efficient analytical methods. In this study, we proposed a generic method for the quantification of 13 pesticides (azoxystrobin, clomazone, diflufenican, dimethachlor, carbendazim, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop and thifensulfuron-methyl) in three environmental matrices. Pesticides from water were extracted using a solid phase extraction system and a single solid-liquid extraction method was optimized for sediment and fish muscle, followed by a unique analysis by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Limits of quantification were below 5 ng L(-1) for water (except for fluroxypyr and iprodion) and ranged between 0.1 ng g(-1) and 57.7 ng g(-1) for sediments and regarding fish, were below 1 ng g(-1) for 8 molecules and were determined between 5 and 49 ng g(-1) for the 5 other compounds. This method was finally used as a new routine practice for environmental research.

Topics: Acetamides; Aminoimidazole Carboxamide; Animals; Benzimidazoles; Carbamates; Chemical Fractionation; Chromatography, Liquid; Environmental Monitoring; Fishes; Geologic Sediments; Hydantoins; Isoxazoles; Methacrylates; Muscles; Naphthalenes; Niacinamide; Oxazolidinones; Pesticide Residues; Pesticides; Phenylurea Compounds; Propionates; Pyrimidines; Quinoxalines; Reproducibility of Results; Solid Phase Extraction; Strobilurins; Sulfonylurea Compounds; Tandem Mass Spectrometry; Thiophenes; Water Pollutants, Chemical

The objective of this work was to test and compare different techniques used in tests for compatibility between the entomopathogenic fungus Beauveria bassiana (Balsamo) Vuill and phytosanitary products, in order to develop a protocol for in vitro tests. Four modes of contact were studied between B bassiana (CG432) and the fungicides iprodione (Rovral) 500 g litre(-1) SC) and azoxystrobin (Amistar) 500 g kg(-1) WG), and the insecticide endosulfan (Thiodan) 350 g litre(-1) EC), at three rates. The techniques consisted in incorporating the products into the culture medium (IM), combining the conidia into the products mix (MP) and spraying the products before (SB) and after (SA) inoculation of the fungus on Petri dishes. The fungitoxic effect of the products was studied on the basis of parameters such as germination, colony-forming units (CFUs), vegetative growth and sporulation. The effect of azoxystrobin on conidial germination was significantly higher in the IM technique than in the other techniques. With regard to CFUs, the IM and SB techniques showed the greatest differences relative to the control. Vegetative growth and sporulation were more affected when azoxystrobin was sprayed before the fungus was applied. At the commercial rate, iprodione had a greater effect on the CFU parameter in the IM and MP techniques, and on vegetative growth in the IM technique, than the other techniques used; however, there was no significant difference occurred between the techniques at the commercial rate with respect to germination and sporulation. Endosulfan was more toxic to germination in techniques SB and SA, and to the CFUs parameter in techniques IM and MP. As to vegetative growth and sporulation, regardless of rate, a more pronounced effect was observed in IM than in the other techniques. It can be inferred that there are differences between techniques and that a standardization of the compatibility tests is necessary. Another inference is that these techniques should reflect realistic exposure of the fungus to chemical formulations under field conditions.

Topics: Acrylates; Aminoimidazole Carboxamide; Animals; Ascomycota; Endosulfan; Fungicides, Industrial; Hydantoins; Insecticides; Methacrylates; Pest Control, Biological; Pyrimidines; Stem Cells; Strobilurins