0
Article Tier 2 Gut & Microbiome Marine & Wildlife Remediation Sign in to save

Microplastic biofilm, associated pathogen and antimicrobial resistance dynamics through a wastewater treatment process incorporating a constructed wetland

Water Research 2023 62 citations

AI summary Read the abstract

This study tracked how microplastic-associated biofilms, pathogens, and antibiotic resistance genes changed through a wastewater treatment process that included a constructed wetland. While the treatment reduced some pathogens, certain antibiotic resistance genes persisted on microplastic surfaces even after treatment. This means microplastics leaving treatment plants could carry drug-resistant bacteria into rivers and lakes, potentially affecting downstream drinking water sources.

Models
Study Type Environmental

Microplastics in wastewater are colonized by biofilms containing pathogens and antimicrobial resistance (AMR) genes that can be exported into receiving water bodies. This study investigated establishment and changes in microplastic-associated biofilm and AMR during a conventional full-scale 2100 population equivalent wastewater treatment process combined with a free water surface polishing constructed wetland. Sequential microplastic colonization experiments were conducted at different stages of the wastewater treatment process, including in raw sewage, treated effluent and the constructed wetland. Two scenarios were tested in which the constructed wetland served as either (i) a polishing step or (ii) as primary recipient of sewage inoculated microplastics. Bacterial 16S rRNA gene sequencing was carried out for qualitative bacterial community analysis. qPCR was applied for quantitative analysis of AMR genes (sul1, ermB, tetW, intiI1), bacterial biomass (16S rRNA) and a human fecal marker (HF183). Microbial diversity on microplastics increased with incubation time. The initial sewage-derived biofilm composition changed more significantly in the wastewater effluent compared to the constructed wetland. Pathogen and AMR load decreased by up to two orders of magnitude after coupled conventional and constructed wetland treatment, while less impact was observed when sewage-inoculated microplastic material was directly transferred into the constructed wetland. Aeromonas, Klebsiella, and Streptococcus were key pathogenic genera correlated with AMR in microplastic-associated biofilms. Despite decreasing trends on human pathogens and AMR load along the treatment process, microplastic-associated biofilms were a considerable potential hotspot for AMR (intI1 gene) and accommodated Cyanobacteria and fish pathogens.

More Papers Like This

Article Tier 2

Growth and prevalence of antibiotic-resistant bacteria in microplastic biofilm from wastewater treatment plant effluents

AI summary Read the abstract

Researchers studied antibiotic-resistant bacteria growing in biofilms on microplastic surfaces in wastewater treatment plant effluent. The study found that microplastic biofilms accumulated antibiotic-resistant bacteria including Pseudomonas, Aeromonas, and Bacillus, and that these biofilms harbored higher concentrations of resistance genes compared to surrounding water, suggesting microplastics may serve as reservoirs for antibiotic resistance.

Article Tier 2

Microplastic biofilms in water treatment systems: Fate and risks of pathogenic bacteria, antibiotic-resistant bacteria, and antibiotic resistance genes

AI summary Read the abstract

This review examines how microplastics in drinking water and wastewater treatment plants develop biofilms that harbor dangerous bacteria and antibiotic resistance genes. The biofilm-coated microplastics can protect pathogens from disinfection processes, allowing them to survive treatment and potentially reach tap water. This raises concerns about microplastics serving as vehicles for antibiotic-resistant bacteria in our water supply.

Article Tier 2

Stage-structured plastisphere succession sustains antibiotic resistomes on microplastics during full-scale A2/O wastewater treatment

AI summary Read the abstract

Tiny bits of plastic that pass through wastewater treatment plants can act like rafts for bacteria carrying antibiotic-resistance genes, and this study found that these "plastic-riding" microbial communities stay more stable and hold onto resistance genes better than bacteria floating freely in the water. That means treated wastewater released into rivers and lakes may still carry microplastic-linked antibiotic-resistant bacteria, which could contribute to the spread of hard-to-treat infections in the environment.

Article Tier 2

The dangerous transporters: A study of microplastic-associated bacteria passing through municipal wastewater treatment

AI summary Read the abstract

This study characterized bacterial communities attached to microplastics sampled from multiple stages of a municipal wastewater treatment plant, finding that diverse bacteria including potential pathogens and antibiotic-resistant strains remained attached to microplastics through all treatment steps. The results suggest microplastics could transport hazardous bacteria through wastewater treatment and into receiving environments.

Article Tier 2

Microbial Succession on Microplastics in Wastewater Treatment Plants: Exploring the Complexities of Microplastic-Microbiome Interactions

AI summary Read the abstract

This review examines how different microorganisms colonize microplastic surfaces in wastewater treatment plants, forming communities called biofilms that change as the treatment process progresses. These biofilms can include harmful bacteria and antibiotic-resistant organisms that ride on microplastics through the treatment process and into the environment. The findings are concerning because microplastics leaving treatment plants could carry disease-causing microbes into waterways used for drinking and recreation.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper