Graham Sustainability Institute

Investigating Biofilms and Antibiotic Resistance in Water

Close-up view of a biofilm


Chuanwu Xi – School of Public Health
Carl F. Marrs – School of Public Health
Carl Simon – Ford School of Public Policy

Project Summary

The emergence of bacterial resistance to antibiotics is quite common in areas where antibiotics are heavily used, but antibiotic-resistant bacteria also increasingly occur in aquatic environments. The spread of antibiotic resistance is a public health concern. Biofilms, which are ubiquitous in surface water environments and drinking water distribution systems, may be contributing to the spread of antibiotic resistance.

The research team used experimental and mathematical modeling approaches to investigate the role of biofilms in the spread of antibiotic resistance in surface water and drinking water. They focused their work on the occurrence of Trimethoprim (TMP) and sulfonamide (SUL) resistance in source and drinking water and built a mathematical model describing natural gene transformation of SUL resistance gene(s) in Acinetobacter BD413 (a bacterium) single-species biofilms in a laboratory system.

The team is continuing to use both state-of-the-art lab techniques and modeling approaches to quantify and to understand how antibiotic resistance spreads in biofilms found in source water and drinking water systems. This work is contributing to the development of new and innovative approaches that reduce risks associated with the spread of antibiotic resistance and increase the safety of our drinking water supplies.

This project received a $140,000 Environmental Sustainability Multidisciplinary Research Team Proposal Grant in 2007.