Anthelminthic Veterinary Medicines Interactions with the Soil Microbiota

Anthelminthics (AHs) are used to control gastrointestinal nematodes (GINs) in productive animals. They are rapidly excreted by animals, ending up in soil through direct deposition of animal dung or application of animal excreta as manures. Most environmental research on AHs has focused on their toxicity to aquatic organisms and soil fauna while their interactions with the soil microbiota, a key component of a functioning soil ecosystem, have been overlooked. In this article, we summarize current knowledge on the interactions of Ahs with the soil (micro) biota, we highlight recent evidence for the toxicity of AHs on soil microorganisms and discuss those results in the frame of the current environmental risk assessment (ERA) of veterinary medicines

Effects of Systemic Pesticides Imidacloprid and Metalaxyl on the Phyllosphere of Pepper Plants

Microbes inhabiting the phyllosphere of crops are exposed to pesticides applied either directly onto plant foliage or indirectly through soil. Although, phyllosphere microbiology has been rapidly evolving, little is still known regarding the impact of pesticides on the epiphytic microbial community and especially on fungi. We determined the impact of two systemic pesticides (metalaxyl and imidacloprid), applied either on foliage or through soil, on the epiphytic fungal and bacterial communities via DGGE and cloning. Both pesticides induced mild effects on the fungal and the bacterial communities. The only exception was the foliage application of imidacloprid which showed a more prominent effect on the fungal community. Cloning showed that the fungal community was dominated by putative plant pathogenic ascomycetes (Erysiphaceae and Cladosporium), while a few basidiomycetes were also present. The former ribotypes were not affected by pesticides application, while selected yeasts (Cryptococcus) were stimulated by the application of imidacloprid suggesting a potential role in its degradation. A less diverse bacterial community was identified in pepper plants. Metalaxyl stimulated an Enterobacteriaceae clone which is an indication of the involvement of members of this family in fungicide degradation. Further studies will focus on the isolation of epiphytic microbes which appear to be stimulated by pesticides application

Identification and characterization of tebuconazole transformation products in soil by combining suspect screening and molecular typology

International audienceOnce released into the environment, pesticides generate transformation products (TPs) which may be of (eco-)toxicological importance. Past studies have demonstrated the difficulty to predict pesticide TP occurrence and their environmental risk by monitoring-driven approaches mostly used in current regulatory frameworks targeting only known toxicologically relevant TPs. We present a novel combined approach which identifies and categorizes known and unknown pesticide TPs in soil by combining suspect screening time-of-flight mass spectrometry with in silico molecular typology. This approach applies an empirical and theoretical pesticide TP library for compound identification by both non-target and target time-of-flight (tandem) mass spectrometry and structural elucidation through a molecular structure correlation program. In silico molecular typology was then used to group the detected TPs according to common molecular descriptors and to indirectly elucidate their environmental properties by analogy to known pesticide compounds having similar molecular descriptors. This approach was evaluated via the identification of TPs of the triazole fungicide tebuconazole occurring in a field dissipation study. Overall, 22 empirical and 12 yet unknown TPs were detected and categorized into three groups with defined environmental properties. This approach combining suspect screening time-of-flight mass spectrometry with molecular typology could be extended to other organic pollutants and used to rationalize the choice of TPs to be intensively studied towards a more comprehensive environmental risk assessment scheme

Diabetes mellitus and cardiovascular risk management in patients with rheumatoid arthritis: an international audit

Aim: The objective was to examine the prevalence of atherosclerotic cardiovascular disease (ASCVD) and its risk factors among patients with RA with diabetes mellitus (RA-DM) and patients with RA without diabetes mellitus (RAwoDM), and to evaluate lipid and blood pressure (BP) goal attainment in RA-DM and RAwoDM in primary and secondary prevention. Methods: The cohort was derived from the Survey of Cardiovascular Disease Risk Factors in Patients with Rheumatoid Arthritis from 53 centres/19 countries/3 continents during 2014-2019. We evaluated the prevalence of cardiovascular disease (CVD) among RA-DM and RAwoDM. The study population was divided into those with and without ASCVD, and within these groups we compared risk factors and CVD preventive treatment between RA-DM and RAwoDM. Results: The study population comprised of 10 543 patients with RA, of whom 1381 (13%) had DM. ASCVD was present in 26.7% in RA-DM compared with 11.6% RAwoDM (p<0.001). The proportion of patients with a diagnosis of hypertension, hyperlipidaemia and use of lipid-lowering or antihypertensive agents was higher among RA-DM than RAwoDM (p<0.001 for all). The majority of patients with ASCVD did not reach the lipid goal of low-density lipoprotein cholesterol <1.8 mmol/L. The lipid goal attainment was statistically and clinically significantly higher in RA-DM compared with RAwoDM both for patients with and without ASCVD. The systolic BP target of <140 mm Hg was reached by the majority of patients, and there were no statistically nor clinically significant differences in attainment of BP targets between RA-DM and RAwoDM. Conclusion: CVD preventive medication use and prevalence of ASCVD were higher in RA-DM than in RAwoDM, and lipid goals were also more frequently obtained in RA-DM. Lessons may be learnt from CVD prevention programmes in DM to clinically benefit patients with RA .The work was supported by grants from the South Eastern Regional Health Authorities of Norway (2013064 for AGS and 2016063 for SR) and FOREUM (the Foundation for Research in Rheumatology for AMK). Further support was through a collaborative agreement for independent research from Eli Lilly who had no role in the study design, data collection and analysis, decision to publish or preparation of the manuscript

Lab to Field Assessment of the Ecotoxicological Impact of Chlorpyrifos, Isoproturon, or Tebuconazole on the Diversity and Composition of the Soil Bacterial Community

Pesticides are intentionally applied to agricultural fields for crop protection. They can harm non-target organisms such as soil microorganisms involved in important ecosystem functions with impacts at the global scale. Within the frame of the pesticide registration process, the ecotoxicological impact of pesticides on soil microorganisms is still based on carbon and nitrogen mineralization tests, despite the availability of more extensive approaches analyzing the abundance, activity or diversity of soil microorganisms. In this study, we used a high-density DNA microarray (PhyloChip) and 16S rDNA amplicon next-generation sequencing (NGS) to analyze the impact of the organophosphate insecticide chlorpyrifos (CHL), the phenyl-urea herbicide isoproturon (IPU), or the triazole fungicide tebuconazole (TCZ) on the diversity and composition of the soil bacterial community. To our knowledge, it is the first time that the combination of these approaches are applied to assess the impact of these three pesticides in a lab-to-field experimental design. The PhyloChip analysis revealed that although no significant changes in the composition of the bacterial community were observed in soil microcosms exposed to the pesticides, significant differences in detected operational taxonomic units (OTUs) were observed in the field experiment between pesticide treatments and control for all three tested pesticides after 70 days of exposure. NGS revealed that the bacterial diversity and composition varied over time. This trend was more marked in the microcosm than in the field study. Only slight but significant transient effects of CHL or TCZ were observed in the microcosm and the field study, respectively. IPU was not found to significantly modify the soil bacterial diversity or composition. Our results are in accordance with conclusions of the Environmental Food Safety Authority (EFSA), which concluded that these three pesticides may have a low risk toward soil microorganisms

Pesticide soil microbial toxicity: setting the scene for a new pesticide risk assessment for soil microorganisms (IUPAC Technical Report)

International audiencePesticides constitute an integral part of modern agriculture. However, there are still concerns about their effects on non-target organisms. To address this the European Commission has imposed a stringent regulatory scheme for new pesticide compounds. Assessment of the aquatic toxicity of pesticides is based on a range of advanced tests. This does not apply to terrestrial ecosystems, where the toxicity of pesticides on soil microorganisms, is based on an outdated and crude test (N mineralization). This regulatory gap is reinforced by the recent methodological and standardization advances in soil microbial ecology. The inclusion of such standardized tools in a revised risk assessment scheme will enable the accurate estimation of the toxicity of pesticides on soil microorganisms and on associated ecosystem services. In this review we (i) summarize recent work in the assessment of the soil microbial toxicity of pesticides and point to ammonia-oxidizing microorganisms (AOM) and arbuscular mycorrhizal fungi (AMF) as most relevant bioindicator groups (ii) identify limitations in the experimental approaches used and propose mitigation solutions, (iii) identify scientific gaps and (iv) propose a new risk assessment procedure to assess the effects of pesticides on soil microorganisms

Application of fingerprinting molecular methods in bioremediation studies

Bioremediation has been identified as a beneficial and effective strategy for the removal of recalcitrant environmental contaminants. Bioaugmentation of polluted environments with exogenous degrading microorganisms constitutes a major strategy of bioremediation. However, the ecological role of these strains and their impact on the endogenous microbial community of the micro-ecosystems where they are released should be known. Fingerprinting PCR-based methods, like denaturating gradient gel electrophoresis(DGGE) and terminal restriction fragment length polymorphism (TRFLP), could be used in studies exploring the ecology of pollutant-degrading microorganisms and their effects on the structure of the soil microbial community. This chapter provides a brief outline of the technical details involved in the application of DGGE and TRFLP fingerprinting in soil microbial ecology, with particular reference to bioremediation studies

Towards a better pesticide policy for the European Union

EABIOmEDOCT INRAThis opinion article aims to foster the debate about pesticide legislation in the European Union (EU). Numerous formerly authorized and widely used pesticides are now banned in the EU because unexpected and unacceptable risks emerged after their initial introduction to the market. Throughout this time lapse, environmental quality and human health have been threatened by the use of these compounds. These hazards could have been prevented by a more responsive pesticide regulatory framework. This article provides detailed insights into the pros and cons of pesticides, and points out weaknesses of the current pesticide environmental risk assessment procedures. Possibilities for improving the robustness and reliability of the pesticide regulatory framework are discussed

Application of the RICEWQ-VADOFT model to simulate leaching of propanil in rice paddies in Greece

In recent years models have become an integral part of the pesticide registration processes. However, there are still no validated models which can adequately describe the specific conditions of rice paddies. Accordingly, this study aimed to evaluate the capability of a proposed model, the RICEWQ-VADOFT model, to simulate leaching of propanil. Model performance was evaluated with a data set derived from a field study (1993–1994) carried out in five paddy fields in the southern part of the Axios river basin. Predicted and measured concentrations of propanil leaching to the deeper soil layer were in good agreement. The Root Mean Square Error (RMSE) and Modeling Efficiency (EF) values calculated for three of the five studied fields varied between 39.4–46.1 and 0.813–0.867, respectively, indicating good model performance. However, little agreement between predicted and observed pesticide concentrations was evident in the remaining two paddies. This was attributed to the presence of preferencial flow mechanisms in these particular fields, which facilitated the rapid transport of high concentrations of propanil into the deeper soil layers, and which the model was not able to predict

Emerging technologies in bioremediation: constraints and opportunities

Intensive industrialisation, inadequate disposal, large-scale manufacturing activities and leaks of organic compounds have resulted in long-term persistent sources of contamination of soil and groundwater. This is a major environmental, policy and health issue because of adverse effects of contaminants on humans and ecosystems. Current technologies for remediation of contaminated sites include chemical and physical remediation, incineration and bioremediation. With recent advancements, bioremediation offers an environmentally friendly, economically viable and socially acceptable option to remove contaminants from the environment. Three main approaches of bioremediation include use of microbes, plants and enzymatic remediation. All three approaches have been used with some success but are limited by various confounding factors. In this paper, we provide a brief overview on the approaches, their limitations and highlights emerging technologies that have potential to revolutionise the enzymatic and plant-based bioremediation approaches