Antimicrobial activity of cationic poly(ethylenimine)

CHED 787

Stephen A. Koplin, Shirley Lin, and Tammy Domanski. Department of Chemistry, United States Naval Academy, 572 Holloway Rd, Annapolis, MD 21402
As infection from drug-resistant microbes becomes more common, the interest in developing antimicrobial coatings for surfaces has increased. This study investigated the antimicrobial activity of a cationic polymer, N-dodecyl-N-methyl-polyethylenimine (PEI). A paint-like method for coating surfaces with polymer, followed by spraying bacteria onto the prepared surfaces, was used to evaluate antimicrobial activity. The antimicrobial effectiveness of this material against gram-positive and gram-negative bacteria was examined. PEI exhibited 100% killing of gram-negative A. baumannii and gram-positive S. aureus in overnight experiments. A time course revealed that 99% of A. baumannii are killed within 5 minutes of contact with the coated surface, but S. aureus only exhibited approximately 55% death after 30 minutes, instead requiring 2 hours to reach 99% death. However, the antimicrobial effect did not persist after a second application of bacteria.