DDI - Apresentações orais em encontros internacionais
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- Exploring the aquatic resistomePublication . Rosado, Tânia; Manageiro, Vera; Balata, Duarte; Menezes, Carina; Ferreira, Eugénia; Paulo, Octávio; Caniça, Manuela; Dias, ElsaAntibiotic resistance is one of the major problems in public health today since the failure of antibiotherapy has dramatic clinical implications such as the increase of mobility/mortality and of health costs. Antibiotic resistance is a dynamic process since antibiotic-resistant microorganisms, and the corresponding genetic material, flows and disseminates among several settings simultaneously: humans, animals and natural habitats. Water environments are recognized as important pools of antibiotic pollution and antibiotic resistance genes, but the water resistome (collection of all genes responsible for antibiotic resistance in water environments) is far from being characterized. It is well known that antibiotic pollution affects the structure/functioning/diversity of aquatic ecosystems, namely the cyanobacteria community. However, the role of cyanobacteria in the context of antibiotic resistance was never characterized. In this presentation, the aims, the team, the methodologies and the preliminary results of the national project EXPLORAR – Exploring the Aquatic Resistome (PTDC/BIA-BMA/31451/2017), founded by the Portuguese Foundation for Science and Technology (FCT, PT) will be discussed. In this project, we are investigating the contribution of indigenous freshwater organisms (cyanobacteria and bacteria) to water resistome. We expect to identify and characterize ecological niches associated with antibiotic resistance in freshwater environments. This may contribute to define a monitoring strategy to map the antibiotic resistance profiles of national freshwater resources. We expect to contribute to the definition of preventive measures against the dissemination of antibiotic resistance in the environment.
- Freshwater cyanobacteria and antibiotic pollution: The Ecotoxicological and Antibiotic Resistance perspectivesPublication . Dias, Elsa; Vasconcelos, Vitor; Caniça, ManuelaThe release of antibiotics in natural ecosystems led to the development of antibiotic resistant (AR) microorganisms and alters the diversity/functioning of natural microbial communities. Freshwater cyanobacteria (CB) have been considered sensitive to antibiotics and they have been used as biologic indicators in environmental risk assessment of water contaminants, such as antibiotics. However, we have shown that CB strains from water environments exhibits reduced susceptibility to some antibiotics (nalidixic acid, trimethoprim), irrespective of the tested specie (Microcystis aeruginosa, Aphanizomenon gracile; Anabaena berghii, Planktothrix agardhii, Planktothrix mougeotti). The failure to detect genes conferring resistance to these antibiotics by PCR does not exclude the possibility of CB harbor AR determinants. NGS sequencing will help us to understand if unknown AR genes are present in CB genomes. Besides, we may also hypothesize that CB are intrinsically resistant to those compounds. On the other hand, the susceptibility to other antibiotics depended of the specie and/or the specie origin (freshwater reservoirs, wastewater treatment plants). Moreover, we also detect genes associated with resistance to other antibiotics (streptomycin, sulfonamides) and a class-1-type integron, in some strains. This suggests that CB might acquire resistant determinants from AR microbiota sharing the same habitats. Thus, the impact of antibiotic pollution in natural occurring CB is far from being elucidated. CB seems to have a role on water resistome but CB communities and their important ecological roles (primary and O2 production, CO2 fixation) may be also hampered by antibiotic exposure.