Associate toxin-antitoxin with CRISPR-Cas to kill multidrug-resistant pathogens.

Area of Science:

• Bacteriology
• Molecular Biology
• Antimicrobial Resistance

Background:

• CRISPR-Cas systems provide adaptive immunity in bacteria.
• Toxin-antitoxin (TA) systems induce cell dormancy or death upon CRISPR-Cas inactivation.
• Bacterial CreTA systems are linked to CRISPR-Cas immunity.

Purpose of the Study:

• To characterize a novel bacterial CreTA system associated with the I-F CRISPR-Cas in Acinetobacter.
• To investigate the mechanism of CreT (toxin) and CreA (antitoxin) action.
• To develop a proof-of-concept antimicrobial strategy (ATTACK) combining CRISPR-Cas and TA.

Main Methods:

• Characterization of the CreTA system in Acinetobacter.
• Identification of CreT as a small RNA toxin targeting protein synthesis machinery.
• Demonstration of CRISPR-Cas targeting antibiotic resistance genes.
• Development and validation of the ATTACK strategy.

Main Results:

• A novel bacterial CreTA system associated with I-F CRISPR-Cas was identified in Acinetobacter.
• CreT was characterized as a small RNA toxin that inhibits protein synthesis.
• CreA was shown to guide CRISPR-Cas for transcriptional repression of CreT.
• The ATTACK strategy effectively targets antibiotic resistance genes in multidrug-resistant pathogens.

Conclusions:

• Bacterial CreTA systems represent a diverse group of RNA toxins coevolving with CRISPR-Cas.
• The ATTACK strategy offers a novel approach to combat multidrug-resistant pathogens by combining CRISPR-Cas and TA systems.
• This combined strategy provides a last-resort cell death mechanism when CRISPR-Cas is inactivated, enhancing its efficacy.