We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
UVA Induced Photoaging of Microplastics Enhances Antibiotic Resistance Gene Enrichment in Sewage Biofilms
AI summary Read the abstract
Scientists found that when sunlight breaks down plastic from disposable cups (like the lining in paper coffee cups) in sewage water, bacteria stick to the damaged plastic more easily and are more likely to trade genes that make them resistant to antibiotics. This matters because it suggests sun-damaged microplastics in wastewater could act as breeding grounds that help "superbugs" develop and spread, potentially making infections harder to treat down the line.
Microplastics are widely distributed across environmental systems, including sewage, which represents an important pathway for antimicrobial resistance (AMR) into aquatic ecosystems. Polyethylene (PE), routinely used as an inner lining in single-use disposable paper cups, represents a potential source of consumer-derived microplastics, whose photoaging may influence AMR dynamics in wastewater. In this study, pristine and UVA-aged polyethylene microplastics were incubated in raw influent sewage at a sewage treatment plant at the IIT Hyderabad. Following 30 days of exposure, microplastic-associated biofilms were retrieved and analysed by quantitative PCR (qPCR) for total bacterial biomass (16S rRNA), an Escherichia coli marker (uidA), six antibiotic resistance genes (ARGs: aph(3″)-Ib, blaCTX-M, blaNDM, qnrS, sul2, tetW), and a mobile genetic element marker (intI1). The highly abundant targets 16S rRNA, aph(3″)-Ib, sul2, and intI1 exhibited higher absolute abundances on aged microplastics, with sul2 and intI1 showing statistically significant increases (p ≤ 0.05) after normalization to 16S rRNA. Conversely, the less abundant ARGs blaCTX-M, blaNDM, and qnrS, together with tetW, exhibited higher levels on pristine microplastics. Scanning electron microscopy revealed bacteria with putative sex pili, structures associated with conjugative horizontal gene transfer (HGT), predominantly on aged microplastics, whereas pristine microplastics mainly showed bacteria with fimbriae. Extracellular polymeric substance (EPS)-rich regions and surface irregularities were also associated with greater bacterial biomass on aged microplastics. Overall, UVA-induced photoaging was associated with enhanced microbial colonization and selective changes in ARG abundance, supporting the potential role of aged microplastics as vectors of AMR in wastewater environments.
More Papers Like This
Photoaged microplastics enhanced the antibiotic resistance dissemination in WWTPs by altering the adsorption behavior of antibiotic resistance plasmids
AI summary Read the abstract
Researchers found that microplastics exposed to UV light become significantly better at attracting and holding antibiotic resistance genes, increasing their capacity by 43 to 48 percent compared to unaged particles. This enhanced adsorption was linked to increased surface roughness and chemical changes on the plastic surface. The study suggests that UV-treated wastewater discharge may inadvertently accelerate the spread of antibiotic resistance in the environment through aged microplastics.
Effects of polymer type and aging on enrichment of antibiotic resistance genes and pathogens in biofilm on microplastics in biological wastewater treatment
AI summary Read the abstract
Tiny plastic particles in wastewater treatment plants act like magnets for bacteria, and this study found that the type of plastic and how much it's been broken down by sunlight both affect how much antibiotic-resistant bacteria build up on its surface. Plastics that break down more easily (like biodegradable PLA) and plastics that had been "aged" by UV light collected especially high levels of antibiotic resistance genes, meaning these microplastics could help spread drug-resistant germs back into our water and environment. This matters because it suggests not all plastics pose the same risk, and even "eco-friendly" biodegradable plast
Aging of microplastics weakens chlorination efficiency and enhances persistence of antibiotic resistance determinants
AI summary Read the abstract
Scientists found that when microplastics get "weathered" by sun exposure (similar to what happens in the environment), they become rougher and stickier, making it easier for bacteria to cling to them and form protective biofilms. In lab tests, this aging effect made standard chlorine water treatment much less effective—weathered microplastics let 2-25 times more antibiotic-resistant bacteria and their resistance genes survive disinfection compared to fresh plastic. While this was a controlled lab study using higher-than-typical microplastic levels, it raises concerns that aging microplastics in wastewater could help antibiotic-resistant
Photoaging microplastics as ecological architects of antibiotic resistance dissemination in aquatic sediments: Shifting bacterial adaptation from metabolic regulation to invasive phenotypes
AI summary Read the abstract
Scientists found that tiny plastic particles in water and sediment environments help spread antibiotic-resistant bacteria - the "superbugs" that are harder to treat with medicines. When these microplastics age from sunlight exposure, they become even better at helping dangerous bacteria multiply and share their resistance to antibiotics with other bacteria. This means that plastic pollution in our waterways could be making it harder for doctors to treat infections in people, creating a serious public health risk.
UV-photoaging of degradable microplastics in atmospheric and wastewater: Surface changes and enhanced antibiotic interaction
AI summary Read the abstract
When biodegradable microplastics spend time in wastewater rather than open air, they age much more aggressively — developing biofilms and oxidized surfaces that dramatically increase their ability to absorb antibiotics. This study found that wastewater-aged polybutylene succinate microplastics adsorbed 2.4 times more tetracycline than fresh plastic, and outperformed air-aged plastic by 40%, driven by biofilm chemistry and increased surface area. The implication is that wastewater treatment systems — rather than solving the microplastic problem — may be transforming biodegradable plastics into potent carriers for antibiotic resistance.
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.