Microplastics in wastewater as a carrier and dispersal route of antibiotic resistance in oceans

Prosjektet har gitt oss ny kunnskap om spredning og utslipp av bakterier med antimikrobilelle resistensgener i avløpsanlegg og vil gi oss et bedre innblikk i hvordan foskjellige typer plastpolymerer danner biofilm som kan spres slike uønskede bakterier. Prosjektet ble dessverre rammet av covid-19 og utveksling samt koordinering be vanskeliggjort, men vi har likevel utviklet felles protokoller for kultivering av biofilm på plastpolymerer og analyse av disse. Vi utviklet også felles protokoller for prøvetaking og sekvensering på MinIon. Flere master og bachelor studenter har gjennomført sine oppgaver i prosjektet, både i Norge og i Sør Afrika. Det samme har også en PhD student i Sør Afrika. Vi vil fortsette å publisere resultater fra dette prosjektet i løpet av 2023, selv om prosjektet formelt avsluttes mars 2023.

Actual relates to the number of MSc and BSc produced in the project, as well as the continuation of the collaboration through a NRC funded grant on microplastics and AMR (MarMib). Potential outcomes are information to policymakers on wastewater treatment strategies, in particular the absence of biological treatment systems. Impacts are the long term commitment due to several projects resulting from this collaboration. The NRC funded project MarMib (Project number 315812 - FORSKER20) continues our joint effort to understand the effects on the interactions between amr and microplastics. Also, IMPACT (Project number: 336411 - BEDREHELSE) is funded from the ideas and progress from this SANOCEAN project. Several other collaborations have been established and grant proposals have been submitted.

Microplastics released through waste water may be a potential source for selecting and spreading antibiotic resistant genes. The biofilms formed on the plastic particles could promote cell to cell contact and thereby enabling horisontal gene transfer of antibiotic resistant genes, as well as functioning as a physical vessel for dissemination of such resistance genes, which of course is a threat to human health. By seasonal sampling of influx and efflux water at waste water treatment plants, we want to investigate the types of microplastics released throughout the seasons, and to examine their affinity for biofilm formations and role in horisontal gene transfer. By comparing waste water treatment plants in South Africa and Norway, we can inform policy makers in both continent as to the threat and effect of microplastic release into the environment when it comes to antibiotic resistance, and potential give science based advice on type of plastics used and on preferable waste water treatment strategies. In the first phase of the project, we want to sample seasonal (spring/autumn) influx and efflux water at 2 different treatment plants in each country - preferably with different waste water treatments and determine physical properties of the filaments and retention efficiencies of the treatments. Then we seek to describe the biofilms formed at the particles, by doing phylogenetic analyses based on 16s sequencing. Antibiotic resistance genes, plasmid specific genes and gene transfer elements determine the possibility for spread of ABres genes aided by biofilms and microplastics. Lab tests of the different types of microplastics found by sampling, may carry different potential for biofilm formation and HGT, and we will test this by laboratory studies (transformation frequencies and biofilm affinity). Lastly, the outcome should be of great interest to policy makers in both countries and will provide science based advice on microplastic handling in the future.