(316c) Synthetic RNA-Inhibitor Antibiotics in Non-Traditional Antibiotic Pathways to Treat Multi-Drug Resistant Bacteria

Multidrug-resistant (MDR) infections are a pressing concern to global health which is made worse by the lack of new antibiotics. The overuse and misuse of current antibiotics has created pandrug-resistant bacteria for which there are no longer effective antibiotics treatments. In particular, an increasing class of gram-negative MDR pathogens like Enterobacteriaceae including carbapenem-resistant Escherichia coli and extended spectrum β-lactamase producing Klebsiella pneumoniae are severely antibiotic resistant and were recently designated priority 1 critical class bacterial pathogens in urgent need of effective antibiotics by the World Health Organization. Here we show that developing synthetic sequence-specific antimicrobials enables us to target non-traditional antibiotic pathways to discover new antibiotic targets and investigate potential combination therapies. Using E. coli as a model organism we created peptide nucleic acid based antisense molecules which target essential genes in non-traditional antibiotic pathways including metabolism, cell signaling, and stress response and have predicted homology in varied species of Enterobacteriaceae. Although the antisense molecules were designed against essential genes in non-pathogenic, drug-sensitive E. coli, these molecules demonstrate therapeutic potential against pathogenic, MDR clinical isolates of E. coli, K. pneumoniae, and S. enterica, thus highlighting the potential to create broad-spectrum yet gene-specific antibiotics using predictive homology. The clinical isolates used in this study are highly resistant to most classes of antibiotics, yet when the antisense molecules are used in combination with traditional antibiotics we observe a strong synergistic effect that significantly inhibits cell growth greater than either mono-therapy. Our findings highlight the potential utility of applying antisense technology to discover novel targets in non-traditional antibiotic pathways.