Skip to main content

River plastics may harbour potential pathogens and antimicrobial resistance genes

Microbial communities growing on plastic debris in rivers may have the capacity to harbour potentially pathogenic microbes and act as reservoirs of antimicrobial resistance genes, according to a study published in Microbiome. The findings also highlight differences in the potential pathogens and antimicrobial resistance genes that new and degraded  plastics may have the capacity to harbour.

Vinko Zadjelovic, Elizabeth Wellington, Joseph Christie-Oleza and colleagues characterised the microbial communities found on the surface of low-density polyethylene plastic films after they were submerged in the River Sowe, UK one kilometre downstream from a wastewater treatment plant for seven days in February 2020. Half of the plastic samples were new and half had been heated in an oven for six months to mimic the degradation or weathering of plastic that often occurs in the environment. They then compared this with microbial communities found on a control surface (wood sticks) that had been submerged in the same river for seven days and with microorganisms extracted from river water samples.

The authors found that plastic, wood and water samples all harboured potentially pathogenic microbes but that the types of potential pathogens extracted from plastic and wood samples differed from those in river water samples. Plastic and wood samples harboured the potential pathogens Pseudomonas aeruginosa, Acinetobacter and Aeromonas — bacteria known as ‘opportunistic’ that pose a greater risk to individuals with compromised immune systems — while water samples contained the potential human pathogens Escherichia, Salmonella, Klebsiella, and Streptococcus. Similarly, the authors found that although antimicrobial resistance genes were present within microorganisms extracted from all samples , the types of antimicrobials that these genes conferred resistance to differed between those from plastic and wood samples, and those from water samples.

When the authors compared the microbial communities growing on new and degraded plastics, they found that P. aeruginosa (which can cause infections in hospital patients) was particularly abundant on degraded plastic samples. They speculate that this could be due to degraded plastics releasing larger amounts of organic compounds that encourage microbial growth than new plastics. They also found that the relative abundance of antimicrobial resistance genes present in microbial communities was higher among those from degraded plastic samples than among those from new plastic samples, however they note that the reasons for this are unclear.

The authors suggest that further research is needed to investigate the potential risks that plastic pollution with the capacity to harbour potentially pathogenic microbes and antimicrobial resistance genes could pose to human health and the spread of antimicrobial resistance genes in the environment.


Media Contact
Deborah Kendall-Cheeseman
Communications Manager
Springer Nature
T: +44 (0)20 7843 2653

Notes to editor:

1. Research article:

“Microbial hitchhikers harbouring antimicrobial‑resistance genes in the riverine plastisphere”
Microbiome 2023
DOI: 10.1186/s40168-023-01662-3
The article is available at the journal website.

Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BMC's open access policy.

2. Microbiome: The scope of the journal encompasses studies of microbiomes colonizing humans, animals, plants or the environment, both built and natural or manipulated, as in agriculture. Studies on the development and application of meta-omics approaches or novel bioinformatics tools, on community/host interaction with emphasis on structure-function relationship that would lead to substantial advances in the field will be considered for publication.

3. A pioneer of open access publishing, BMC has an evolving portfolio of high quality peer-reviewed journals including broad interest titles such as BMC Biology and BMC Medicine, specialist journals such as Malaria Journal and Microbiome, and the BMC series. At BMC, research is always in progress. We are committed to continual innovation to better support the needs of our communities, ensuring the integrity of the research we publish, and championing the benefits of open research. BMC is part of Springer Nature, giving us greater opportunities to help authors connect and advance discoveries across the world.