March 11, 2025

expert reaction to a lab study of microplastics and antimicrobial resistance (AMR)

A study published in Applied and Environmental Microbiology looks at the possibility of microplastics contributing to AMR.

Prof Shilpa Chokshi, Head of Environmental Hepatology at the University of Plymouth, said:

“This study provides intriguing laboratory-based evidence that microplastics may contribute to antimicrobial resistance (AMR), an issue of growing global concern.  However, while the findings suggest that microplastics can influence resistance in controlled lab conditions in a short experimental timeframe, it is important to interpret these results carefully.

“This was a lab study using E. coli and four antibiotics under controlled conditions, which does not fully replicate real-world complexity.  Further research is needed to assess whether these effects translate to human infections or environmental settings. 

“For patients with liver cirrhosis, currently the 11^th leading cause of death worldwide, AMR is a significant concern, with 35% acquiring hospital-related infections, of which 34% involve multidrug-resistant organisms (MDROs).  Given the projected rise in AMR-related deaths to 10 million by 2050, understanding all potential contributors is crucial. However, this study does not establish a direct link between microplastics and AMR-driven infections in patients, and further research is required before making firm conclusions. Tackling plastic pollution may be one piece of the puzzle in addressing AMR, particularly in vulnerable populations such as those with liver disease, but more evidence is needed to fully understand these interactions.”

Prof David Graham, Emeritus Professor of Engineering, Newcastle University, said:

“The findings of this lab study are interesting but not unexpected.  I think the authors have performed their experiments well, but the problem is how to translate their relative importance to the real world. 

“The study only considers one phenomenon that might influence antimicrobial resistance transmission and spread. It might be true that microplastics can potentially increase antimicrobial resistance (AMR), but more work is needed to determine the importance of microplastics, given most AMR spread is simply caused by inadequately treated wastewater.”

“The authors have described a mechanism by which microplastics can increase AMR, but whether it has that effect in the real world is a different question altogether. Much more work is needed to contextualise the results in more complex systems, i.e., can the effects by replicated in nature and how important are the effects compared relative to other drivers of AMR?  Lab data alone can’t answer these questions. 

“To establish the impact of microplastics on AMR in nature we need to examine the way organisms behave in the presence of microplastics, and whether they really have much of an impact when all the other factors are considered.  In my experience, the impact of human waste entering the environment dwarfs every other factor when it comes to AMR.

“So, although the findings of this lab study provide some interesting avenues for academic investigation, it’s too much of a leap to conclude that microplastics increase antimicrobial resistance in the real world.  Comparative work is needed beside other drivers of AMR to determine what is and what is not practically important.  Regardless, this research is useful, providing researchers with additional targets for prevention – a critical issue in reducing AMR at all scales.”

‘Effects of microplastic concentration, composition, and size on Escherichia coli biofilm associated antimicrobial resistance’ by Neila Gross et al. was published in Applied and Environmental Microbiology at 1pm UK time on Tuesday 11 March.

Declared interests

David Graham: no interests to declare

Shilpa Chokshi: none to declare