We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Hidden threats in the plastisphere: Carbapenemase-producing Enterobacterales colonizing microplastics in river water
Summary
Researchers placed microplastics in a river near a wastewater treatment plant and found that antibiotic-resistant bacteria, including dangerous carbapenem-resistant strains, colonized the plastic surfaces. These bacteria carried multiple drug-resistance genes and virulence traits, making them potential threats to human health. The study demonstrates that microplastics in waterways can serve as floating platforms that help spread antibiotic-resistant superbugs from wastewater into the broader environment.
Carbapenem resistance poses a significant burden on healthcare systems worldwide. Microplastics (MPs) have emerged as potential contributors to antibiotic resistance spread in the environment. However, the link between MPs and carbapenem resistance remains unexplored. We investigated the prevalence of carbapenem-resistant bacteria colonizing MPs placed in a river. Three replicates of a mixture of polypropylene (PP), polyethylene (PE) and polyethylene terephthalate (PET) and of PET alone were placed both upstream and downstream a wastewater treatment plant (WWTP) discharge. Carbapenem-resistant Enterobacterales (CRE) were further characterized by phenotypic tests and whole-genome sequencing. The abundance of carbapenem-resistant bacteria on MPs increased significantly downstream the WWTP. Their prevalence was higher in the MPs mixture compared to PET alone. CRE strains colonizing MPs included Klebsiella pneumoniae (n = 3), Klebsiella quasipneumoniae (n = 3), Raoultella ornithinolytica (n = 2), Enterobacter kobei (n = 1) and Citrobacter freundii (n = 1), most (n = 8) recovered after the WWTP discharge. All strains exhibited at least one of the tested virulence traits (biofilm formation at 37 °C, haemolytic activity and siderophore production), were multi-drug resistant and carried carbapenemase-encoding genes [bla (n = 5), bla (n = 2) or bla + bla (n = 3)]. Uncommon phenotypes of resistance to imipenem/relebactam (n = 3) and ceftazidime/avibactam (n = 2) were observed. Two bla-positive K. pneumoniae successfully transfer this gene trough conjugation. Genome analysis predicted all strains as human pathogens. The bla was associated with the Tn4401d transposon on a pBK30683-like plasmid in most of the isolates (n = 7). The bla was mostly linked to class 3 integrons. A K. pneumoniae strain belonging to the outbreak-causing high-risk clone ST15 carried both bla and bla. Two K. quasipneumoniae isolates carried the plasmid-mediated colistin resistance gene mcr-9. Our results underscore the role of MPs as vectors for CRE dissemination, particularly following WWTPs discharges. MPs may act as carriers, facilitating the dissemination of carbapenemase-encoding genes and potentially contributing to increased CRE incidence in the environment.
Sign in to start a discussion.
More Papers Like This
Exploiting microplastics and the plastisphere for the surveillance of human pathogenic bacteria discharged into surface waters in wastewater effluent
Researchers placed small plastic particles in rivers upstream and downstream of a wastewater treatment plant and found that disease-causing bacteria, including E. coli and Klebsiella, quickly formed biofilms on them within 24 hours. These biofilms carried antibiotic resistance genes and virulence factors, showing that microplastics in waterways can serve as floating platforms for dangerous bacteria that pose risks to human health.
Microplastics accumulate priority antibiotic-resistant pathogens: Evidence from the riverine plastisphere
Researchers placed microplastics in river water and found they accumulated more antibiotic-resistant bacteria than natural sand particles, including dangerous pathogens like E. coli and Klebsiella. Most of the bacteria isolated from the plastic surfaces were multi-drug resistant and carried virulence traits like biofilm formation. This suggests microplastics in waterways may act as rafts for spreading antibiotic resistance through the environment.
Antibiotic resistance genes and virulence factors in the plastisphere in wastewater treatment plant effluent: Health risk quantification and driving mechanism interpretation
Researchers found that microplastics in treated wastewater carry significantly more disease-causing bacteria, antibiotic resistance genes, and virulence factors on their surfaces compared to the surrounding water. This means microplastics released from wastewater treatment plants into rivers and lakes could spread antibiotic-resistant infections, posing a direct risk to communities that rely on these water sources.
Assessment of Emerging Pathogens and Antibiotic Resistance Genes in the Biofilm of Microplastics Incubated Under a Wastewater Discharge Simulation
Researchers incubated common plastic types in flowing water that simulated wastewater discharge conditions for 10 weeks and studied the bacteria that colonized the plastic surfaces. They found that microplastics exposed to treated wastewater developed distinct bacterial communities compared to those in clean river water, including emerging pathogens and antibiotic resistance genes. The study suggests that microplastics in waterways receiving wastewater may serve as mobile platforms for spreading harmful bacteria and antibiotic resistance in the environment.
Size effects of microplastics on antibiotic resistome and core microbiome in an urban river
Scientists found that microplastics in an urban river serve as platforms for antibiotic-resistant bacteria and dangerous pathogens including Pseudomonas aeruginosa, Mycobacterium tuberculosis, and Legionella pneumophila. Larger microplastic particles harbored more antibiotic resistance genes, and the concentrations of these genes were much higher on plastic surfaces than in the surrounding water. This research raises concerns that microplastics in waterways could spread drug-resistant infections by providing a surface where dangerous bacteria thrive and share resistance genes.