Paper Number
BB11 

Session
Biomaterials and Biological Systems

Title
Mechanistic action of weak acid drugs on biofilms

Presentation Date and Time
October 11, 2017 (Wednesday) 4:10

Track / Room
Track 1 / Crystal A

Authors (Click on name to view author profile)

1. Kundukad, Binu (Singapore MIT Alliance for Research and Technology, Biosystems and Micromechanics)
2. Schussman, Megan (Massachusetts Institute of Technology)
3. Yang, Kaiyuan (National University of Singapore)
4. Seviour, Thomas (Nanyang Technological University)
5. Yang, Liang (Nanyang Technological University)
6. Rice, Scott (Nanyang Technological University)
7. Staffan, Kjelleberg (Nanyang Technological University)
8. Doyle, Patrick S. (Massachusetts Institute of Technology)

Author and Affiliation Lines (in printed abstract book)
Binu Kundukad¹, Megan Schussman², Kaiyuan Yang³, Thomas Seviour⁴, Liang Yang⁴, Scott Rice⁴, Kjelleberg Staffan⁴, and Patrick S. Doyle^5
1Biosystems and Micromechanics, Singapore MIT Alliance for Research and Technology, Singapore, Singapore; ²Massachusetts Institute of Technology, Cambridge, MA; ³National University of Singapore, Singapore, Singapore; ⁴Nanyang Technological University, Singapore, Singapore; ⁵Massachusetts Institute of Technology, Cambridge, MA

Speaker / Presenter 
Kundukad, Binu

Text of Abstract
Selective permeability of a biofilm matrix to some drugs has resulted in the development of drug tolerant bacteria. Here we studied the efficacy of a weak organic acid drug, N-acetyl-L-cysteine (NAC), on the eradication of biofilms formed by the mucoid strain of Pseudomonas aeruginosa and investigated the commonality of this drug with that of acetic acid. We showed that NAC and acetic acid at pH <pKa can penetrate the matrix and eventually kill 100% of the bacteria embedded in the biofilm. Once the bacteria are killed, the microcolonies swell in size and passively shed bacteria, suggesting that the bacteria act as crosslinkers within the extracellular matrix. Despite shedding of the bacteria, the remnant matrix remains intact and behaves as a pH-responsive hydrogel. These studies not only have implications for drug design but also offer a route to generate robust soft matter materials.