Authors: Alyson Camacho, Camille Bryner, Bowen Houser
Mentors: William Pitt
Insitution: Brigham Young University
Current methods for the diagnosis of bacterial infections require time consuming cultures. To prevent deaths caused by sepsis, faster methods for bacterial identification and antibiotic susceptibility methods are urgently needed. Necessary to these faster methods is the ability to separate and concentrate bacteria. While techniques such as filtering and centrifugation have been explored for this purpose, we propose an innovative approach. Polydopamine (pDA) is a remarkably adhesive polymer that has been used to create antibacterial and anti-biofouling coatings on medical devices. In this study, however, we show how magnetic nanoparticles (MNPs) coated with pDA can selectively bind and remove specific bacteria from suspensions. For these experiments, pDA- MNPs were added to suspensions of bacteria mixtures and allowed to bind for 10 minutes. The MNP/bacteria mixture was then placed on a holder with a magnet which collected the MNPs on the side of the test tube. Finally, the bacterial supernatant was carefully removed and plated. Capture efficiency of the beads was calculated and it was shown that the pDA-coated MNPs preferentially isolated S. epidermidis from a suspension of both S. epidermidis and E. coli. This approach holds great potential for separating bacteria from clinical samples like urine or blood, enabling faster and more efficient diagnosis of bacterial infections.