Projects per year
Abstract
Bacteria have extraordinary ways to deal with stress in general and antibiotics in particular. The use and at times unnecessary overuse of antibiotics has resulted in the rapid development and spread of resistance to multiple types of antibiotics in pathogenic bacteria. Therefore, a very limited number of antibiotics, if any, remain available to fight certain multidrug resistant pathogens, such as methicillin resistant Staphylococcus aureus (MRSA). Aside from this inheritable antibiotic resistance, multidrug tolerance can also be linked to a non-inheritable trait by entering a dormant state called persistence. Because antibiotics predominantly work on metabolically active cells, these bacteria are capable to withstand different antibiotics during the time of treatment. Bacterial toxin-antitoxin (TA) modules may be a solution. They consist of a toxin (which has a deleterious effect on the cell) and an antitoxin (which rescues the cell from the toxin’s activity) and have to be tightly regulated to prevent cell death. Deregulation of these tightly regulated systems can therefore inhibit cell growth and kill the bacteria.
My PhD work can be divided into two parts. The first part focuses on the regulation of a unique three component TA module: the paaR2-paaA2-parE2 operon. This operon is present in cryptic prophage CP-933P from enterohemorrhagic Escherichia coli O157:H7 strains. Aside from the toxin (ParE2) and antitoxin (PaaA2), there is an additional regulator (PaaR2) that is a transcriptional repressor of the operon. The objective of my work was to understand how these three components interact to autoregulate the operon. Expression clones and purification protocols were established, and it has been shown via a combination of structural biology, biochemistry, biophysical experiments and DNA-binding studies that the regulation hijacks a prophage regulation pathway. The second part of my PhD deals with the validation of TA modules as potential leads for new antibiotics. This work was performed using E. coli and S. aureus as model organisms. MRSA as well as multidrug resistant E. coli are becoming more prevalent and pose a high risk for hospitalized patients. Exogenous toxins from TA modules were introduced into these organisms and the effect of the toxins was evaluated. This research brings us a step closer to understanding how TA modules are regulated as well as being a first stage in the use of toxins as antimicrobials.
My PhD work can be divided into two parts. The first part focuses on the regulation of a unique three component TA module: the paaR2-paaA2-parE2 operon. This operon is present in cryptic prophage CP-933P from enterohemorrhagic Escherichia coli O157:H7 strains. Aside from the toxin (ParE2) and antitoxin (PaaA2), there is an additional regulator (PaaR2) that is a transcriptional repressor of the operon. The objective of my work was to understand how these three components interact to autoregulate the operon. Expression clones and purification protocols were established, and it has been shown via a combination of structural biology, biochemistry, biophysical experiments and DNA-binding studies that the regulation hijacks a prophage regulation pathway. The second part of my PhD deals with the validation of TA modules as potential leads for new antibiotics. This work was performed using E. coli and S. aureus as model organisms. MRSA as well as multidrug resistant E. coli are becoming more prevalent and pose a high risk for hospitalized patients. Exogenous toxins from TA modules were introduced into these organisms and the effect of the toxins was evaluated. This research brings us a step closer to understanding how TA modules are regulated as well as being a first stage in the use of toxins as antimicrobials.
Original language | English |
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Qualification | Doctor of Bioengineering Sciences |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 1 Jan 1970 |
Place of Publication | Brussels |
Publication status | Published - 2021 |
Fingerprint
Dive into the research topics of 'Toxin-antitoxin modules: functional characterization of transcription regulation and potential use against pathogenic bacteria'. Together they form a unique fingerprint.Projects
- 2 Finished
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OZRSRF12: Structural flexibility and disorder in protein function: from toxin-antitoxin modules to bacterial persistence - SRF mandate
1/10/18 → 30/09/23
Project: Fundamental
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FWOAL831: Regulation of persistence by the paaAR-paaA2-parE2 and cog4197-duf1019 operons from E. coli O157
1/01/17 → 31/12/20
Project: Fundamental
Research output
- 6 Article
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Bistable expression of a toxin-antitoxin system located in a cryptic prophage of Escherichia coliO157:H7
Jurenas, D., Fraikin, N., Goormaghtigh, F., De Bruyn, P., Vandervelde, A., Jove, T., Charlier, D., Loris, R. & Van Melderen, L., 21 Dec 2021, In: mBio. 12, 6, 15 p., e0294721.Research output: Contribution to journal › Article › peer-review
Open AccessFile12 Citations (Scopus)164 Downloads (Pure) -
Molecular architecture of the endocytic TPLATE complex
Yperman, K., Wang, J., Eeckhout, D., Winkler, J., Vu, L. D., Vandorpe, M., Grones, P., Mylle, E., Kraus, M., Merceron, R., Nolf, J., Mor, E., De Bruyn, P., Loris, R., Potocký, M., Savvides, S., De Rybel, B., De Jaeger, G., Van Damme, D. & Pleskot, R., 24 Feb 2021, In: Science Advances. 7, 9, 16 p., eabe7999.Research output: Contribution to journal › Article › peer-review
Open AccessFile31 Citations (Scopus)183 Downloads (Pure) -
Nanobody-aided crystallization of the transcription regulator PaaR2 from Escherichia coli O157:H7
De Bruyn, P., Prolic Kalinsek, M., Vandervelde, A., Malfait, M., Sterckx, Y., Sobott, F., Hadzi, S., Pardon, E., Steyaert, J. & Loris, R., 1 Oct 2021, In: Acta Crystallographica Section F - Structural Biology Communications. 77, 10, p. 374-384 11 p., 11.Research output: Contribution to journal › Article › peer-review
Open AccessFile1 Citation (Scopus)167 Downloads (Pure)
Activities
- 1 Member of PhD committee
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PhD Thesis defense Pieter De Bruyn - Toxin-antitoxin modules: functional characterization of transcription regulation and potential use against pathogenic bacteria (Event)
Eveline Peeters (Chair), Inge Van Molle (Jury), Kim Roelants (Jury), Remy Loris (Supervisor), Henri De Greve (Supervisor), Tanel Tenson (Jury) & Jan Michiels (Jury)
2 Sep 2021Activity: Membership › Member of PhD committee