Multidrug-resistant bacterial infection is becoming a health crisis worldwide. Treatments for previously ?untreatable? bacterial infection have been the spotlights of antibacterial studies, including minimizing the emergence, spread and persistence of drug-resistance genes, as well as directly neutralizing virulence factors. Many of these bacterial pathogens possess retractile pili, which are either part of secretion systems required for gene/protein transfer, or responsible for virulence. In this project, it is proposed to manipulate pili through ssRNA phages as an anti-virulence strategy against pathogenic bacteria and/or dissemination of antibiotic resistance genes. From the preliminary data, the infection of ssRNA phage MS2 or Q? was found to cause the detachment of E. coli conjugative F-pilus through single-cell studies using fluorescence microscopy.
Aim 1 is to examine the F-pili detachment efficiency by varying different mutants of Type IV section systems and growth conditions, and investigate how to reach 100% detachment efficiency. In addition, the study will be expanded to other types of retractile pili and their ssRNA phage systems for pili detachment.
Aim 2 is to identify the essential components of ssRNA phages for F-pilus detachment and design novel minimal systems or virus-like particles to efficiently detach the F-pilus.
This project aims to reveal how ssRNA phages cause F-pili detachment and to design ssRNA phage-based minimal systems to efficiently detach F-pili using fluorescence microscopy and single-particle cryo-EM. This study provides a new approach to reduce/eliminate virulence factors and dissemination of antibiotic resistance genes. The approaches used in this project can be applied to other pathogenic bacteria containing retractile pili that ssRNA phages can infect, which can facilitate our effort to disarm various pathogenic bacteria.
