Escherichia coli Metagenome
Introduction: The rampant misuse and overuse of antibiotics have precipitated the emergence of multidrug-resistant and pan drug-resistant bacteria, constituting a formidable global health threat. Antibiotic adjuvants that potentiate the efficacy of existing antibiotics represent a particularly promising avenue to address this challenge.Methods: We performed genome-wide CRISPRi screening to identify homologous recombination pathway as broad-spectrum potential targets for antibiotic adjuvants. Additionally, we employed three distinct strategies to limit expression and function of recA, a key protein in homologous recombination pathway, including dCas9-sgRNA system delivered via conjugation, RecX-20 peptide fused with cell-penetrating motif, and an inhibitor cisplatin, validated by surface plasmon resonance.Results: Inhibition of homologous recombination pathway significantly increased bacterial susceptibility to multiple antibiotic classes (quinolones, beta-lactams, aminoglycosides, and nitrofurantoin) while reducing horizontal gene transfer of antibiotic resistance. RecA deficiency led to membrane damage, and impaired efflux pump activity, resulting in higher intracellular antibiotic accumulation and oxidative stress. Cisplatin was identified as a RecA inhibitor, enhanced multiple antibiotic efficacies against MDR pathogens both in vitro and in vivo.Conclusions: Our work provides novel insights into the development of broad-spectrum antibiotic adjuvants to restore the efficacy of existing antibiotics, and offers an effective solution to combat the growing threat of drug-resistant bacterial infections.