Breaking the biofilm barrier: CRISPRi-guided investigation of Pseudomonas aeruginosa susceptibility to natural products

Abstract

Antibiotic resistance is a growing concern, with pathogens such as Pseudomonas aeruginosa evolving resistance to clinical treatments. Furthermore, our race against antibiotic resistance is worsened by a slowdown in novel antibiotic discovery. The Gram-negative bacterium P. aeruginosa often causes infections in patients with cystic fibrosis and poses a particular threat due to its ability to form biofilms, which are stable supercellular structures that adhere to surfaces and enhance resistance to antibiotics. However, natural products are promising sources for discovering new antimicrobial compounds. This project investigates the mechanism by which a recently discovered antibacterial natural product and a semi-synthetic derivative inhibit P. aeruginosa and its biofilm formation. Full genome CRISPR-interference (CRISPRi) knockdown strains of P. aeruginosa PA14 were utilized to identify the genetic and biochemical targets of the natural product and its analog. By elucidating the mechanism of how biofilm formation is inhibited, this research aims to reveal vulnerable genes and pathways that can be targeted for future antibiotic development, with implications for treating P. aeruginosa and potentially other comparable pathogens.