Combating biofilms and antibiotic resistance using synthetic biology

Bacterial infections represent a significant source of morbidity and mortality. Biofilms and antibiotic resistance pose challenges to our future ability to treat bacterial diseases with antibiotics (1). Bacteria frequently live in biofilms, which are surface-associated communities encased in a hydrated extracellular polymeric substances (EPS) matrix (2, 3). Biofilms are crucial in the pathogenesis of many clinically-important infections and are difficult to eradicate because they exhibit resistance to antimicrobial agents and removal by host immune systems (4). Antibiotics can even induce biofilm formation (5, 6). The development of antibiotic-resistant bacteria is also a growing medical problem. Antibiotic resistance genes can be acquired by horizontal gene transfer and passed vertically to later generations (7). Antibiotic resistance can also result from persistence, a phenomena in which a subpopulation of cells can withstand antibiotic treatment without containing antibiotic-resistance genes (8). These problems, coupled with decreasing output of new antibiotics, have highlighted the need for new treatments for bacterial infections (1, 9-12). I developed three novel strategies for attacking bacterial biofilms and antibiotic resistance using synthetic biology. To remove biofilms, I engineered bacteriophage to express a biofilm degrading enzyme during infection to simultaneously attack biofilm cells and the biofilm EPS matrix. These enzymatically-active bacteriophage substantially reduced biofilm cell counts by 4.5 orders of magnitude (-99.997% removal), which was about two orders of magnitude better than that of non-enzymatic phage. To address antibiotic-resistant bacteria, I targeted gene networks with synthetic bacteriophage to create antibiotic adjuvants.

Department dc:contributor.department

Harvard University--MIT Division of Health Sciences and Technology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2008

Author dc:creator

• Lu, Timothy K. (Timothy Kuan-Ta), 1981-

Advisor dc:contributor.advisor

• James J. Collins.

• Harvard University--MIT Division of Health Sciences and Technology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/43868

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/43868