Periodic Reporting for period 3 - ChronosAntibiotics (Exploring the bacterial cell cycle to re-sensitize antibiotic-resistant bacteria)
Berichtszeitraum: 2021-03-01 bis 2022-08-31
Over the next 35 years, antibiotic resistant bacteria are expected to kill more than 300 million people. This problem is aggravated by the current pandemic and the associated secondary bacterial infections that often ensue respiratory viral infections. The need to find alternative strategies for antimicrobial therapies remains a global challenge with several bottlenecks in the antibiotic discovery process. To address this challenge, we need to deeply understand the biology of bacterial pathogens, and use that knowledge to develop new antimicrobial agents, which constitute the two overall aims of this project.
Using Staphylococcus aureus, the most common multidrug-resistant bacterium in the European Union and an excellent model organism for cell division in cocci, we are studying the bacterial cell cycle to find new regulators for cell cycle progression. We hypothesize that there are windows of opportunity during the cell cycle, during which bacteria are more susceptible or more tolerant to the action of antibiotics. We have screened 2000 mutants in non-essential S. aureus genes and found 50 that are impaired in cell cycle progression, possibly affecting the duration of these windows of opportunity for antibiotics. We are currently studying the corresponding proteins, to understand their role in cell cycle regulation.
At the same time, we are developing S. aureus reporter strains for the identification of new antimicrobial compounds. These strains encode fluorescent proteins under the control of promoters that respond to the inhibition of specific metabolic pathways. We currently have reporter strains that detect inhibition of cell wall synthesis, DNA damage, loss of membrane potential and of fatty acids biosynthesis and are working towards increasing this list. These strains should be useful for whole-cell screens for new antibiotics, as well as to study the mode of action of new compounds with antimicrobial activity.
At the same time, we are developing S. aureus reporter strains for the identification of new antimicrobial compounds. These strains encode fluorescent proteins under the control of promoters that respond to the inhibition of specific metabolic pathways. We currently have reporter strains that detect inhibition of cell wall synthesis, DNA damage, loss of membrane potential and of fatty acids biosynthesis and are working towards increasing this list. These strains should be useful for whole-cell screens for new antibiotics, as well as to study the mode of action of new compounds with antimicrobial activity.
By the end of this project we aim to (i) identify new regulators of the bacterial cell cycle and test if they can be used to manipulate the length of phases of the cell cycle during which bacteria are more susceptible to the action of antibiotics; (ii) construct reporter strains that respond to the inhibition of various cellular pathways, that can be used to screen for novel antibiotics and to investigate the mode of action of new compounds with antimicrobial activity.