The microplastic pollution caused by the broken-down styrofoam containers—yes, that discarded package that held your hamburger—may significantly contribute to the growing resistance to antibiotics that is a leading cause of fatalities.
According to scientists at Rice University’s George R. Brown School of Engineering, whose study was published in the Journal of Hazardous Materials, this discarded packaging not only provides a cozy environment for microbes and chemical contaminants, but also for the “free-floating genetic materials” that enable antimicrobial resistance (AMR).
An analysis published at the beginning of January showed that, in 2019, more than 1.2 million people worldwide died as a direct result of AMR. That’s more global deaths than were caused by AIDS (860,000) or malaria (640,000) that year. Furthermore, the analysis found, nearly 5 million fatalities that year can be linked to AMR. The Center for Disease Dynamics, Economics & Policy has warned that even simple bacterial infections would cause people to die if AMR is left unaddressed.
Platforms for antibiotic-resistant genes
The ultraviolet aging of microplastics (100 nanometers to five micrometers in diameter) discarded in the environment make them suitable platforms for antibiotic-resistant genes (ARGs), which are armored with all biological vectors that can spread AMR to people—bacterial chromosomes, phages, and plasmids, weakening their ability to fight infections, the Rice University scientists said.
The depolymerization chemicals draining away from the degrading microplastics give these ARGs an opportunity to invade microbes by breaching their membranes, and increased “the susceptibility of vectors to horizontal gene transfer, through which resistance spreads,” said Pedro Alvarez, professor of civil and environmental engineering and director of the Rice University-based Nanotechnology Enabled Water Treatment Center, in an article on the university’s website.
“We were surprised to discover that microplastic aging enhances horizontal ARG,” Alvarez said. “Enhanced dissemination of antibiotic resistance is an overlooked potential impact of microplastics pollution.”
“Microplastic surfaces may serve as aggregation sites for susceptible bacteria, accelerating gene transfer by bringing the bacteria into contact with each other and with released chemicals. That synergy could enrich environmental conditions favorable to antibiotic resistance even in the absence of antibiotics,” according to Rice.
