New science reveals that nanoplastics dramatically enhance the virulence of E. coli, putting public health at risk. This pathogen is well-known for making people sick with foodborne illness. The study, led by Pratik Banerjee, an associate professor in the Department of Food Science and Human Nutrition, examined how these tiny plastic particles interact with E. coli O157:H7, a strain frequently associated with outbreaks.
The research was done in highly controlled laboratory environments. It was looking at the impacts of polystyrene nanoplastics, the same type of material you’d find in a white clamshell-style takeout container, on E. coli. Researchers first exposed positively, neutrally, or negatively charged nanoplastics to freely swimming E. coli and those attached in biofilms.
These results indicate that E. coli exposed to positively charged nanoplastics experienced high levels of stress. This exposure resulted in a harmful upregulation of the production of Shiga-like toxins, which are toxic to humans. Moreover, biofilm-associated E. coli exhibited more robust stress responses upon exposure to positively charged particles.
Banerjee reiterated that their findings have major real-world implications outside of the lab. They identified mechanisms by which prior exposures to plastic particles might increase E. coli toxicity. He noted that biofilms developing on microplastics can create hotspots for exchanging antibiotic resistance genes. Unfortunately, this discovery further complicates the management of pathogenic bacteria.
“Biofilms are a very robust bacterial structure and are hard to eradicate. They’re a big problem in the medical industry, forming on inserts like catheters or implants, and in the food industry,” – Pratik Banerjee
The study specifically focused on E. coli O157:H7, underscoring its status as a key pathogen implicated in foodborne illness outbreaks. This study draws attention to the role of nanoplastics in promoting bacterial pathogenicity. As Banerjee says, we need more research to understand the effects of all the other chemicals that these plastics absorb.
“We started with the surface charge. Plastics have an enormous ability to adsorb chemicals. Each chemical has a different effect on surface charge, based on how much chemical is adsorbed and on what kind of plastic,” – Banerjee
He added that previous research has examined how nanoplastics interact with bacteria but emphasized that this study is pioneering in its focus on human pathogenic bacteria like E. coli O157:H7.
“We didn’t look at the effects of the chemicals themselves in this paper—that’s our next study—but this is the first step in understanding how the surface charge of plastics impacts pathogenic E. coli response,” – Banerjee
This study’s findings are significant contributions to the medical technology industry. They emphasize increasing costs and risks in the food industry from biofilms and nanoplastics. Learning more about how these interactions operate can bring us one step closer to creating an effective risk-reduction strategy for E. coli. This understanding will further enhance our food safety practices.