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Article

Exploiting microplastics and the plastisphere for the surveillance of human pathogenic bacteria discharged into surface waters in wastewater effluent

Details

Citation

Woodford L, Messer LF, Ormsby MJ, White HL, Fellows R & Quilliam RS (2025) Exploiting microplastics and the plastisphere for the surveillance of human pathogenic bacteria discharged into surface waters in wastewater effluent. Water Research, 281, p. 123563. https://doi.org/10.1016/j.watres.2025.123563

Abstract
Discharge from wastewater treatment plants (WWTPs) is a well-characterised source of human pathogens and antimicrobial resistance genes entering the environment. However, determining whether pathogens released from effluent into surface waters are viable, and consequently pose a risk to human health, is hindered by the use of transient grab-sampling monitoring approaches. Here we present a novel surveillance system using low-cost microparticles (polyethylene, cork and rubber) deployed upstream and downstream of a WWTP effluent pipe, that exploits the ability of bacterial pathogens to form biofilms. Using quantitative culture-based and molecular methods, viable E. coli, Klebsiella spp., Citrobacter spp., and Enterococcus spp. were identified after only 24-hour of deployment. Moreover, these pathogens were continually present at each timepoint (2, 4, 6, 8, 10, 14 and 23 days) as biofilm communities matured, with all pathogens detected at higher concentrations downstream of the WWTP effluent pipe. Long-read whole genome sequencing revealed a suite of plasmids, virulence genes and antimicrobial resistance genes in bacterial pathogens isolated from biofilms formed downstream of the effluent pipe. Furthermore, recognising that pathogens are typically present at proportionally low concentrations within mixed biofilm communities, total biofilm pathogenicity was confirmed using a Galleria mellonella infection model. Full-length 16S rRNA gene sequencing revealed that human pathogens present in microplastic biofilms (the ¡®plastisphere¡¯) dominated the microbial community of infected G. mellonella larvae within 24 hr, suggesting these bacteria remained highly virulent. Overall, this study demonstrated the efficacy of an easy-to-deploy system for the surveillance and rapid detection of pathogenic bacteria being discharged from point-source pollution. We envisage that if used as part of an integrated environmental management approach, this approach could help to reduce the public and environmental health risks of human pathogens and antimicrobial resistance genes, by monitoring viable human pathogens entering surface waters.

Journal
Water Research: Volume 281

StatusPublished
Publication date31/08/2025
Publication date online31/03/2025
Date accepted by journal25/03/2025
URL
PublisherElsevier BV
ISSN0043-1354

People (3)

Miss Rosie Fellows

Miss Rosie Fellows

Research Assistant, Biological and Environmental Sciences

Dr Lauren Messer

Dr Lauren Messer

Post Doctoral Research Fellow, Biological and Environmental Sciences

Professor Richard Quilliam

Professor Richard Quilliam

Professor, Biological and Environmental Sciences

Projects (2)

Files (1)