Gene-Targeted Antimicrobial Strategies Using CRISPR-Cas Systems Against Multidrug-Resistant Bacterial Pathogens

Abstract

The rapid emergence of antibiotic-resistant bacteria has significantly outpaced the development of new antimicrobial agents, posing a global health threat. This review investigates the application of CRISPR-Cas9 and CRISPR-dCas9 systems as innovative strategies to combat resistance in key bacterial pathogens. A systematic literature search identified studies focused on methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. In MRSA, the CRISPR-dCas9 system was used to suppress mecA gene transcription, leading to a 77% reduction in gene expression without compromising bacterial viability-an approach with implications for microbiome-safe interventions. In contrast, CRISPR-Cas9 targeting of conserved ESBL gene sequences in E. coli successfully cleaved resistance determinants, resulting in >99% re-sensitization to β-lactam antibiotics. The engineered pRESAFRESBL plasmid demonstrated cross-sensitivity restoration, suggesting plasmid-wide disruption of co-transferred resistance genes. Together, these findings highlight the transformative potential of CRISPR-based technologies in reversing resistance phenotypes through precise, gene-targeted interventions. This approach paves the way for next-generation antimicrobial therapies that either neutralize resistance while preserving beneficial flora or directly eradicate resistant clone