Plastic-associated pathogens in marine environments: a meta-analysis

The global accumulation of plastic debris in marine ecosystems is continually increasing. Understanding the interaction between these debris and the bacterial biofilm on their surface is essential, particularly with regard to potential human pathogenic bacteria (PHPB). In this meta-analysis, we re-evaluated 16S rRNA metabarcoding data from 52 plastisphere-related studies, published up to 2024. We compared the bacteriomes of plastics and other marine substrates, identifying PHPB associated with each type of substrate. Did not appear more abundant nor richer in the plastisphere than in other marine solid substrates. Nevertheless, we described a distinctive PHPB signature associated with plastics, including Vibrionaceae bacteria (4 % of the whole plastisphere) and particularly Vibrio alginolyticus. The contribution of other marine substrates to plastic PHPB was quantified and we found that shell and wood substrates were potential sources of PHPB for plastics. Our results suggest that both plastics and other marine solid substrates could serve as reservoirs for PHPB. However, plastics convey specific PHPB communities, and due to their ubiquity and persistence in marine ecosystems, plastic debris poses a higher risk as fomites compared to other substrates.