Frontiers in antibiotic resistance: emerging alternatives, key challenges, and the transformative role of CRISPR-Cas

Antibiotic resistance (AR) emergence is a significant hazard to public health. The AR bacteria have driven the exploration of diverse alternative strategies, including antimicrobial peptides, bacteriocins, phage therapy, predatory bacteria, nanomaterials, phytochemicals, anti-quorum sensing agents, fecal microbial transplants, vaccines, antibodies, AI-driven tools, and CRISPR-Cas9. While each approach offers unique advantages, many face challenges, including stability, host specificity, toxicity, and scalability. Among these, CRISPR-Cas9 is a state-of-the-art technology that offers unprecedented precision in targeting AR genes. It enables selective disruption of resistance mechanisms within bacterial genomes while sparing the surrounding microbiota. However, the practical application of CRISPR-Cas9 as an antimicrobial therapy is hindered by challenges in its effective delivery to bacterial cells. Several delivery methods have been explored to address these challenges, including physical approaches like electroporation, conjugative plasmid-mediated systems, bacteriophage-based viral vectors, and nanoparticle-mediated delivery. These methods enhance the specificity and efficacy of CRISPR-based antimicrobials by ensuring precise delivery to target bacterial populations. This paper highlights the CRISPR-Cas9 system and its advanced delivery strategies, alongside a comprehensive review of the history of antibiotics, the emergence of resistance, and alternative antimicrobial approaches. By combining CRISPR-Cas9 with innovative delivery technologies, this next-generation platform offers a highly promising solution for addressing AR and advancing the treatment of infectious diseases.