Search results

(1 - 2 of 2)
Engineering Escherichia coli to produce and secrete colicins for rapid and selective biofilm cell killing
Title
Engineering Escherichia coli to produce and secrete colicins for rapid and selective biofilm cell killing
Creator
Jin, Xing, An, Sungjun, Kightlinger, Weston, Zhou, Jiacheng, Hong, Seok Hoon
Date
2021
Description
Bacterial biofilms are associated with chronic infectious diseases and are highly resistant to conventional antibiotics. Antimicrobial...
Show moreBacterial biofilms are associated with chronic infectious diseases and are highly resistant to conventional antibiotics. Antimicrobial bacteriocins are alternatives to conventional antibiotics and are characterized by unique cell-killing mechanisms, including pore formation on cell membranes, nuclease activity, and cell wall synthesis inhibition. Here, we used cell-free protein synthesis to rapidly evaluate the antibiofilm activities of colicins E1, E2, and E3. We found that E2 (with DNase activity) most effectively killed target biofilm cells (i.e., the K361 strain) while leaving nontargeted biofilms intact. We then engineered probiotic Escherichia coli microorganisms with genetic circuits to controllably synthesize and secrete colicin E2, which successfully inhibited biofilms and killed preformed indicator biofilms. Our findings suggest that colicins rapidly and selectively kill target biofilm cells in multispecies biofilms and demonstrate the potential of using microorganisms engineered to produce antimicrobial colicin proteins as live therapeutic strategies to treat biofilm-associated infections.
Sponsorship: NIH-R15AI130988
Show less
DEVELOPING FUSION BACTERIOCINS FOR ERADICATING PSEUDOMONAS AERUGINOSA BIOFILMS
Title
DEVELOPING FUSION BACTERIOCINS FOR ERADICATING PSEUDOMONAS AERUGINOSA BIOFILMS
Creator
An, Sungjun
Date
2022
Description
The opportunistic pathogen Pseudomonas aeruginosa is a leading cause of morbidity and mortality in cystic fibrosis patients and...
Show moreThe opportunistic pathogen Pseudomonas aeruginosa is a leading cause of morbidity and mortality in cystic fibrosis patients and immunocompromised individuals. Due to its remarkable ability to resist antibiotics, eradicating P. aeruginosa has become increasingly difficult. As previously reported, we have successfully engineered a colicin-secretion system that kills target biofilm cells rapidly and selectively in multispecies biofilms as well as demonstrated the potential of using live microorganisms engineered to produce antimicrobial colicin protein to treat biofilm-associated infections. In this study,we constructed a fusion colicin-pyocin that could target P. aeruginosa by DNase activity of colicin E2. The newly engineered bacteriocin-secretion system upon the shift in target, maintained biofilm inhibition capacity. Both during biofilm formation and after its development, the system was able to suppress the P. aeruginosa biofilm. This result opened up the possibility that it could be used for novel live biotherapeutics. A further study was conducted to overcome the challenge of requiring an exogenous inducer. We applied the concept of Quorum-Sensing signal that recognize autoinducer as a trigger of fusion colicin-pyocin producing genetic circuit so that it automates the production and secretion of fusion colicin-pyocin as soon as the genetic circuit senses the target population growing. This study demonstrated that combining the domains of colicin and pyocin could broaden the genetic circuit target range, maintaining strain specificity, while employing the QS system could remove the fundamental problem of diffusion or degradation of extra compounds as they approach engineered cells.
Show less