The typology of organic wastes influences dose-response relationships between sulfonamide residues and antibiotic resistance genes in amended soils.

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Development of a soft extraction method for sulfamethoxazole and transformation products from agricultural soils: Effects of organic matter co-extraction on the environmental availability assessment

The recycling of biosolids and livestock manure in agriculture may lead to the introduction of antibiotic residues, i.e., parent molecule and transformation products, into amended soils. Their fate in soils can be approached through the assessment of their environmental availability. In this work, the environmental availability of sulfamethoxazole (SMX) and three transformation products (N4-acetyl-SMX, 3-amino-5-methylisoxazole, aniline) was assessed in soils amended with sludge compost or cow manure throughout a three-month incubation, using soft extractions with CaCl2, EDTA or cyclodextrin solutions. First, the freeze-storage of soil samples was shown to decrease the SMX extractability. The SMX extractability depended on the initial concentration, the amendment type and the extracting solution at day 0. From 1.9% up to 63% of the SMX total content was initially extractable. The lowest fractions were quantified in EDTA extracts in which the dissolved organic matter was the most complex and responsible for high matrix effects in mass spectrometry compared to CaCl2 extracts. The purification of cyclodextrin extracts highly reduced the matrix effects, but CaCl2 was considered as the most suitable extractant. SMX extractability strongly decreased after the first 8days of incubation to finally reach 0.4-0.8% after 84days, whatever the initial conditions. This high decrease could be related to humification observed through the increasing complexity of extracted dissolved organic matter. Very low levels of transformation products were quantified throughout the incubation period. The low environmental availability of SMX was mainly due to its sorption on soil organic matter and resulted in its low biotransformation in these amended soils

A new UHPLC-MS/MS analytical method to assess the environmental availability of sulfamethoxazole and three transformation products in soil amended with manure

A new UHPLC-MS/MS analytical method to assess the environmental availability of sulfamethoxazole and three transformation products in soil amended with manure. 1st International Conference on the Risk Assessment of PHarmaceuticals in the Environmen

Assessing the environmental availability of sulfamethoxazole and its acetylated metabolite in agricultural soils amended with compost and manure: an experimental and modeling study

Assessing the environmental availability of sulfamethoxazole and its acetylated metabolite in agricultural soils amended with compost and manure: an experimental and modeling study. EGU 2017, European Geophysical Union General Assembly 201

Impact écotoxicologique d’un antibiotique sur les processus microbiens du cycle de l’azote, dans des sols amendés par des produits résiduaires organiques

The environmental concern regarding the antibiotics has increased considerably, due to their intensive uses in human and veterinary medicines and the growing interest in organic wastes recycling as soil amendments. While the occurrence and persistence of antibiotics and antimicrobial resistance in environm ent have become major human health issues, their ecotoxicological impacts on microbial ecosystem processes (organic matter degradation and nutrient recycling) are not well understood. The exposure (fate and bioavailability of antibiotics) and ecological ch aracteristics of microbial communities (resistance and resilience) influence the impacts. Organic matter is a key environmental factor influencing the dissipation and the bioavailability of antibiotics, in soils. Also, organic matter and nutrient inputs in fluence microbial communities in amended soil. Our objectives were to investigate the effects of the sulfamethoxazole (SMX) on microbial nitrogen transformations. A dose - effect approach was performed with different doses of SMX added to different organic w astes (compost of sewage sludge - green waste (SGW), farmyard manure (FYM)), before their mixing on soil microcosms. The final concentrations of SMX in amended soils ranged from 0.022 to 2.22 mg kg - 1 dw , with control soil microcosms amended with SGW or FYM without SMX. Nitrogen forms, potential nitrification and denitrification activities were determined in soils, after 8, 28 and 84 days following amendments. The total and available concentrations of SMX were extracted with organic and aqueous solutions, res pectively, and then quantified by UPLC - MS/MS. Only the nitrification activity was adversely impaired by SMX, following a dose - response pattern, in SGW amended soils, but not in FYM amended soils. These effects were related to the soil nitrate contents in soil - SGW, as functional output. The chemical assessment of SMX availability did not show strong differences between the SGW or FYM amended soils, in opposite to nitrification response. Actually, the acute toxicity of SMX, following a bacteriostatic action, can be only detected on growing microbial populations, such as nitrifiers, in SGW amended soils with high NH 4 + levels. Denitrification activity was not consistently affected by SMX, despite high nutrient levels (nitrate and organic carbon). Nitrification appeared as a sensitive indicator of SMX effects on soil microbial functioning, while denitrification seemed to be more resistant. Different level of taxonomic diversity can explain these differences. In addition, the magnitude of effects of low doses of S MX (< 0.5 mg kg - 1 dw ) slightly decrease after 84 days of exposure, compared to days 8 and 28, in accordance with the decrease of SMX availability, measured in SGW amended soils. This highlighted resilience capabilities of soil nitrification, following short - term impairments, which could be promoted by dissipation of SMX, leading to a decrease of its bioavailability. Analytical chemistry plays an important role in understanding ecotoxicity through the assessment of exposure scenario

Environmental availability of sulfamethoxazole and its acetylated metabolite added to soils via sludge compost or bovine manure

The fate of antibiotics and their metabolites in soils after application of organic waste depends on their environmental availability, which depends on the quality and biodegradability of the added exogenous organic matter (EOM). This study aimed at better understanding the fate of sulfamethoxazole (SMX) and N‑acetyl‑sulfamethoxazole (AcSMX) metabolite added to soils via sludge compost or cow manure application, during a 28-day incubation. Experimental results obtained for mineralized, extractable, and non-extractable fractions as well as EOM mineralization were used to couple SMX and AcSMX dynamics to the EOM evolution using the COP-Soil model. According to various mechanisms of extraction, CaCl2, EDTA and cyclodextrin solutions extracted contrasted available fractions (31–96% on day 0), resulting in different sets of parameter values in the model. CaCl2 extraction was the best method to assess the sulfonamide availability, leading to low relative root mean squared errors and best simulations of SMX and AcSMX dynamics. The decrease of SMX and AcSMX availability over time went with the formation of non-extractable residues, mostly of physicochemical origin. Using the COP-Soil model, the co-metabolism was assumed to be responsible for the formation of biogenic non-extractable residues and the low mineralization of SMX and AcSMX

A new extraction method to assess the environmental availability of ciprofloxacin in agricultural soils amended with exogenous organic matter

Fluoroquinolone antibiotics such as ciprofloxacin can be found in soils receiving exogenous organic matter (EOM). Their long-term behavior in EOM-amended soils and their level of biodegradability are not well understood partly due to a lack of methods to estimate their environmental availability. We performed different aqueous extractions to quantify the available fraction of 14C-ciprofloxacin in soils amended with a compost of sewage sludge and green wastes or a farmyard manure contaminated at relevant environmental concentrations.After minimizing 14C-ciprofloxacin losses by adsorption on laboratory vessel tubes, three out of eleven different aqueous solutions were selected, i.e., Borax, Na2EDTA and 2-hydroxypropyl-β-cyclodextrin. During 28 d of incubation, the non-extractable fractions were very high in all samples, i.e., 57–67% of the initial 14C-activity, and the availability of the antibiotic was very low, explaining its low biodegradation. A maximum of 6.3% of the initial 14C-activity was extracted from soil/compost mixtures with the Na2EDTA solution, and 7.2% from soil/manure mixtures with the Borax solution. The available fraction level was stable over the incubation in soil/compost mixtures but slightly varied in soil/manure mixtures following the organic matter decomposition.The choice of different soft extractants highlighted different sorption mechanisms controlling the environmental availability of ciprofloxacin, where the pH and the quality of the applied EOM appeared to be determinant

Exposures of soil microbial communities to realistic antibiotics concentrations: key parameters for environmental risk assessment

While the occurrence and persistence of antibiotics in environment are recognized as ma- jor environmental and human health issues, their ecotoxicological impacts on soil microbial communities are still overlooked for environmental risk assessment. Most available studies highlight effects on soil microbial communities at antibiotic concentrations or under exposure pathways that are far from realistic conditions. To investigate the relationships between SMX (sulfamethoxazole) availability and impact on microbial nitrogen-cycling communities and antibiotic resistance genes (ARGs), a dose-effect approach was performed, with sludge com- post or farmyard manure amended soil microcosms. The organic wastes were contaminated before mixing in soils, to obtain SMX concentration surrounding those usually measured in amended agricultural soils. Microbial descriptors were monitored during 84 days following amendments. The total and available fractions of SMX were quantified by UPLC-MS/MS. At these low but environmentally realistic concentrations, only nitrification was impaired by SMX, in compost-amended soils and little consistent effect was observed on denitrification. However, SMX availability was similar in both compost- or manure-amended soils, thus not explain the short-term effects. A temporal decrease of SMX availability contributed to the nitrification recovery, in compost-amended soils. The dynamics of ARGs were partly ex- plained by SMX gradient, but the duration of the experiment and the type of organic waste influenced the ARGs responses to SMX. Although it is necessary to define normal operating ranges of these descriptors, for further interpretations of their suitability as indicators in risk assessment, nitrification and abundances of ARGs are sensitive descriptors of AB effects on soil microbial functioning

Correction to: What are the effective solutions to control the dissemination of antibiotic resistance in the environment? A systematic review protocol

International audienceCorrection to: Environ Evid (2018) 7:3 https ://doi.org/10.1186/s1375 0-018-0118-2 : Following publication of the original article [1], the authors reported that wrong website were hyperlinked in the “Methods” section of the paper. The article has been updated and the links have been removed.Reference :1. Goulas A, Livoreil B, Grall N, Benoit P, Couderc-Obert C, Dagot C, Patureau D, Petit F, Laouénan C, Andremont A. What are the effective solutionsto control the dissemination of antibiotic resistance in the environment? A systematic review protocol. Environ Evid. 2018;7:3. https ://doi.org/10.1186/s1375 0-018-0118-2. HAL Id : hal-0172487