With this project it was possible for the first time, to the best of my knowledge, to construct a stable multi-species consortium of 4 different wastewater bacteria species. This consortium of 4 strains was selected from an initial sample of 63 isolates by the following an approach designed by me tha tincliuded several steps from identification of the species to evaluate the different interactions types occurring between all, by analysing different combinations of 1 to 4 different strains.
The presence and activity of the beta-lactamases enzymes was accessed by a novel approach (construction of a fusion protein including the gene for a beta-lactamase protein and the gene of a reporter protein) being both expressed as a unique protein under the control of the beta-lactamase native promotor. The expression of such fusion protein enables to reveal that beta-lactamases are expressed and active at the periplasm of the producer cells and also in the extracellular, degrading the beta-lactam antibiotic outside of the cells.
Each strain was able to transfer beta-lactamases genes for all other 3 strains of the consortium by horizontal gene transfer. Furthermore, by increasing the number of strains in the biofilm consortium demonstrated that the complexity of the species diversity of the biofilm is correlated with the ability of the bacteria escape from the AB action.
From the thorough analysis of the beta-lactam resistome and microbiome from each treatment points of 2 full-scale WWTP, it was possible to pinpointing the exact treatments (secondary treatment and the disinfection steps) that impact on the dissemination of antibiotic resistance. These results were obtained for the discharged effluent and reused effluent, by analyzing genomic DNA and eDNA.
Exploitation and dissemination:
During the action, the outputs of the project were exploited and disseminated by different means, in all with the reference of the EU funding:
Scientific conferences and symposiums:
• BAGECO 15, 26-30 May 2019, Lisbon, Portugal;
• FEMS 2019 7-11th July 2019, Glasgow, Scotland
• The Danish Microbial Society Annual Congress 2019, 11th November 2019, Copenhagen, Denmark
• Biofilm minisymposium, 13 – 14 August 2018, The Maersk tower, University of Copenhagen, Denmark;
Scientific manuscripts for publication in Peer review scientific journals
• A manuscript entitled “The environmental contribution to carbapenem resistance dissemination by discharged and reused wastewater effluents: the role of cellular and extracellular DNA” is in the process or replying to the reviewer’s comments after submission in the journal Water Research
Outreach activities and other means than scientific publications
• Dansk Naturvidenskabsfestival, visiting the NGG International School, Hørshom,
• Interview to the University Journal (Uniavisen, Copenhagen University);
• Event days to introduce the activities and projects (including my MSCA IF project) developed at the Section of Microbiology, KU, to high school students and bachelor students searching for a Master theme
• Section of Microbiology webpage at KU website
• Twitter account (@AnaSilv82987273) and LinkedIn (linkedin.com/in/silvaafc) pages
