• Bonnineau, C.
• Dagot, Christophe
• Laurent, F. Martin
• Labanowski, Jérôme
• Bouchez, Agnes

Abstract

Since the early 20's antibiotics have been massively produced and consumed for the benefit of both human and animal healths. Nevertheless, antibiotics have also reached the aquatic environment through diffuse sources (e.g. veterinary treatment) and through wastewater. Consequently, antibiotics concentrations between the ng/L and µg/L range are regularly detected in surface water. Antibiotics have also been found in sediments and aquatic biota. The ubiquitous presence of antibiotics exert a selective pressure on microbial communities leading to the acquisition and dissemination of antibioresistance in the environment. While both antibiotics and antibioresistance have been found in different aquatic compartments, more investigation is required to better understand their repartition and to identify hotspots of accumulation. Microbial resistance to antibiotics is commonly assessed by quantifying resistance genes or isolating antibiotic resistant bacteria. Nevertheless, other techniques of antibioresistance assessment do not require a priori knowledge of resistance genes or cultivable bacteria. For instance, integrons are mobile genetic elements involved in antibiotic resistance and commonly found in human, animal and in the environment. Previous studies highlighted a strong link between integrons and multi-resistance to antibiotics, suggesting the use of integrons as biomarker of antibioresistance. Antibiotic resistance can also be estimated by measuring the acquisition of antibiotics tolerance at community level, following a PICT approach (Pollution Induced Community Tolerance). These approaches have been previously used to link pesticides exposure and biological effects. Assessing the tolerance of natural microbial community to antibiotics, following a PICT approach, is therefore likely to reveal microbial exposure to antibiotics and to highlight the acquisition of resistance to antibiotics. Aquatic microbial communities adapted to antibiotics contamination are also likely to develop biodegradation potential as observed in soil community. Thus, estimating the importance of microbial degradation of antibiotics could inform us on the potential role of these communities on antibiotics dynamics. To tackle these research questions, the ANTIBIO-TOOLS project gathers 5 complementary research teams with the aim of (i) investigating the repartition of antibiotics and antibioresistance in different aquatic compartments; (ii) comparing various methods of antibioresistance detection and (iii) exploring the role of microbial community in antibiotic biodegradation. To do so, a 2-year campaign will be conducted on 2 sites belonging to regional observatories and presenting contrasting levels to pharmaceuticals : the Arve river belonging to Sipibel and the Geneva lake belonging to the Observatory of Alpins Lakes. On each sampling campaign, the following parameters will be determined : (i) antibiotics levels in water, sediments and periphyton; (ii) antibioresistance in periphyton and sediments using various techniques : detection of resistance genes, integrons quantification, detection of tolerance acquisition via a PICT approach ; (iii) antibiotics biodegradation potential of microbial community from sediments (by radiorespirometric measurement) ; (iv) diversity of bacteria and diatoms in periphyton and sedments; (v) physico-chemical parameters and (vi) metallic contamination in sediments. Thus, the project ANTIBIO-TOOLS should provide helpful information on the dynamic of antibioresistance in the aquatic environment: hotspots, temporal variability, influence of biotic and abiotic factors (e.g. microbial community composition, antibiotics contamination). By comparing the response of various tools monitoring antibioresistance, this project will provide guidelines for their use. Finally highlighting a potential microbial degradation of antibiotics would be promising for monitoring natural attenuation and potential recovery of the environment.

Topics

• impedance spectroscopy
• surface