MICROPLASTIC AS AN EMERGING VECTOR FOR FOODBORNE PATHOGENS IN THE FOOD CHAIN; PLASTPATH

Quite a lot of attention has during the last years been paid to the health risk associated with microplastics in the environment and in food. However, the assessments done are so far inconclusive, and the Norwegian Scientific Committee for Food and Environment affirms that still very limited data of acceptable quality are available on levels of microplastics in foods. In PLASTPATH, we will study if environmental microplastic plays a role in the dissemination and protection of bacteria and virus in food and water. Our hypothesis is that bacteria and virus hitch-hike with the microplastics within the food production chain and therefore travel longer and more protected compared to free microbes. If so, abundant microplastic would be a risk of acquiring food- and waterborne diseases.

The project will characterize the microbe populations on the surface of microplastics in wastewater and sludge at two wastewater treatment plants and in water collected from a river. Furthermore, we will investigate how these microbe-populations develop in several controlled laboratory experiments. Lastly, we will evaluate the importance of microplastic attachment for the survival of microbes through the gastrointestinal system, and how this attachment influences the virulence of food- and waterborne pathogens. If PLASTPATH indeed finds microplastics to increase survival and dissemination of microbial pathogens in the food-chain and through water-systems, the project has highlighted the importance of regulating the amount of microplastics in the environment.

PLASTPATH is a collaboration between the Faculty of Veterinary Medicine, NMBU, NTNU Ålesund, NOFIMA, University of Barcelona and VEAS and “Lier vei, vann og avløp” wastewater plants.

PLASTPATH will contribute to food safety by addressing the hitherto neglected, but potential, food-related hazard to human health represented by microbial communities associated with microplastics (MP) (the plastisphere). MPs are small plastic particles that have a size of 5 mm or less. These ubiquitous environmental contaminants may harm ecosystems and their presence is expected to increase dramatically over the next decade. The complexity of challenges related to pollution from MPs is larger than previously thought, and concerns are now expressed about new contamination routes where MPs act as vectors for the introduction of pathogens into the food and drinking water supplies. MPs can be colonized by microorganisms, building up microbial biofilms that are different from the microbiomes associated with natural particles such as stones and material from vegetation. Due to their low biodegradability and extreme persistence in the environment, it is believed that MPs can serve as vectors for long distance transfer of bacteria and viruses that are pathogenic to humans and animals. Our hypothesis is that MPs serve as vectors for foodborne pathogens by protecting the hitchhiking microorganisms from stressors in the environment, in the food and in the digestive system and by facilitating interaction with intestinal epithelial cells.

PLASTPATH is organized into four scientific workpackages, and each workpackage is responsible for one of the four subobjectives of PLASTPATH: 1) Characterize MP associated microbial communities in Norwegian sewage and sludge from WWTPs and freshwater environments, 2) Develop a microfluidic platform in order to study establishment of plastispheres in controlled environments, 3) Study the survival, adhesion and potential uptake of the plastisphere through the digestive system in in vitro and ex vivo models, and 4) Study the survival, adhesion and potential uptake of plastispheres through the digestive system in an in vivo model (the Medaka fish).

PLASTPATH combines new developments within microfluidics technology with modern metagenomic-based analyses of microbial communities as well as studies of infectivity with advanced biological experimental models. To ensure biological and technological interdisciplinarity, the PLASTPATH team consists of research groups from two faculties at NMBU; Faculty of Veterinary Medicine and Faculty of Science and Technology, from NOFIMA and from Department of Microbiology, University of Barcelona. Collaboration with two WWTPs is established to facilitate field sampling and input from important stakeholders.