We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Photoaged nanoplastics with multienzyme-like activities significantly shape the horizontal transfer of antibiotic resistance genes
AI summary Read the abstract
Researchers found that UV-aged polystyrene nanoplastics develop enzyme-like activity that generates reactive oxygen species, enabling them to suppress horizontal gene transfer of antibiotic resistance genes at higher concentrations by degrading plasmid DNA and damaging bacterial membranes — a paradoxical finding where pollution aging may inhibit antibiotic resistance spread under some conditions.
Nanoplastics (NPs), identified as emerging pollutants, pose a great risk to environment and global public health, exerting profound influences on the prevalence and dissemination of antibiotic resistance genes (ARGs). Despite evidence suggesting that nano-sized plastic particles can facilitate the horizontal gene transfer (HGT) of ARGs, it is imperative to explore strategies for inhibiting the transfer of ARGs. Currently, limited information exists regarding the characteristics of environmentally aged NPs and their impact on ARGs propagation. Herein, we investigated the impact of photo-aged NPs on the transfer of ARG-carrying plasmids into Escherichia coli (E. coli) cells. Following simulated sunlight irradiation, photo-aged nano-sized polystyrene plastics (PS NPs) exhibited multiple enzyme-like activities, including peroxidase (POD) and oxidase (OXD), leading to a burst of reactive oxygen species (ROS). At relatively low concentrations (0.1, 1 μg/mL), both pristine and aged PS NPs facilitated the transfer of pUC19 and pHSG396 plasmids within E. coli due to moderate ROS production and enhanced cell membrane permeability. Intriguingly, at relatively high concentrations (5, 10 μg/mL), aged PS NPs significantly suppressed plasmids transformation. The non-unidirectional impact of aged PS NPs involved the overproduction of ROS (•OH and •O) via nanozyme activity, directly degrading ARGs and damaging plasmid structure. Additionally, oxidative damage to bacteria resulted from the presence of much toxic free radicals, causing physical damage to cell membranes, reduction of the SOS response and restriction of adenosine-triphosphate (ATP) supply, ultimately leading to inactivation of recipient cells. This study unveils the intrinsic multienzyme-like activity of environmentally aged NPs, highlighting their potential to impede the transfer and dissemination of ARGs.
More Papers Like This
Impact of aging of primary and secondary polystyrene nanoplastics on the transmission of antibiotic resistance genes in anaerobic digestion
AI summary Read the abstract
Researchers studied how aged and non-aged nanoplastics from both manufactured and environmentally degraded polystyrene affect the spread of antibiotic resistance genes during sewage sludge treatment. They found that higher concentrations of nanoplastics inhibited the treatment process and increased the abundance of antibiotic resistance genes, with environmentally degraded particles having a stronger effect due to their altered surface properties. The study raises concerns that nanoplastic pollution in sewage systems may be contributing to the spread of antibiotic resistance.
The unexpected role of aged microplastics in inhibiting antibiotic resistance gene spread
AI summary Read the abstract
Aged (weathered) microplastics were unexpectedly found to inhibit antibiotic resistance gene transfer between bacteria compared to virgin plastics. This surprising result suggests that the physical and chemical changes plastics undergo in the environment can alter their role in spreading antibiotic resistance, a key public health concern.
Effects of aging of polyethylene microplastics and polystyrene nanoplastics on antibiotic resistance gene transfer during primary sludge fermentation
AI summary Read the abstract
This study found that aged (weathered) microplastics and nanoplastics promoted the spread of antibiotic resistance genes during sewage sludge treatment more than fresh plastics did. The weathering process changed the surface properties of the plastics, making them better carriers for drug-resistant bacteria and their genes. This is concerning because sludge from treatment plants is often applied to farmland, potentially spreading antibiotic resistance through soil and into the food supply.
UV-aged biodegradable and non-biodegradable microplastics further enhance horizontal transfer of antibiotic resistance plasmids both in vitro and in intestinal flora
AI summary Read the abstract
Researchers found that both petroleum-based and biodegradable microplastics significantly increase the horizontal transfer of antibiotic resistance genes between bacteria, and UV aging amplified this effect by 4 to 20 times. The aged particles disrupted bacterial cell membranes, increased oxidative stress, and boosted bacterial energy metabolism, all of which facilitated gene transfer. The study also showed that UV-aged microplastics promoted antibiotic resistance spread in gut bacteria in living organisms, raising concerns about environmental plastic degradation and public health.
Aging attenuates threat: how moderate aging of microplastics suppresses antibiotic resistance gene proliferation during sludge anaerobic digestion
AI summary Read the abstract
Researchers examined how the degree of weathering of polyethylene and polypropylene microplastics affects their tendency to promote antibiotic resistance gene spread during sewage sludge digestion, and found a counterintuitive U-shaped relationship: moderately aged plastics actually suppressed resistance gene proliferation by up to 50% compared to fresh plastics, while more heavily aged plastics saw the effect bounce back. The mechanism involves weathering altering how microplastics affect microbial stress responses and gene transfer pathways. The findings highlight that the environmental history of microplastics matters when assessing their biological risks.
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.