CRISPR-Enhanced Phage Therapy for Multi-Drug Resistant Bacterial Infections: Mechanisms, Engineering Strategies, and Clinical Prospects

Antibiotic resistance represents one of the most urgent global health threats, rendering conventional antimicrobial therapies increasingly ineffective. Bacteriophage therapy has re-emerged as a promising alternative, offering microbial specificity and the capacity to target pathogens unresponsive to existing antibiotics. However, natural phages face limitations including narrow host range, unpredictable pharmacokinetics, and the rapid evolution of phage-resistant bacterial mutants. Advances in CRISPR-Cas genome editing have enabled the development of engineered phages that incorporate programmable DNA or RNA targeting systems, greatly enhancing their therapeutic precision and versatility. CRISPR-enhanced phages can selectively disrupt chromosomal genes essential for survival, eliminate antibiotic resistance plasmids, modulate virulence factor expression, and expand their natural host range. This review synthesises current knowledge on CRISPR–bacteria interactions, engineering strategies for constructing enhanced phages, and their demonstrated applications against multidrug-resistant pathogens, such as MRSA, Pseudomonas aeruginosa, CRE, and Acinetobacter baumannii. Challenges related to delivery, biosafety, immune responses, and regulatory oversight are critically evaluated. Overall, CRISPR-enhanced phage therapy represents a transformative approach with significant potential to address the rising burden of antibiotic resistance.