Xanthomonadales bacteriofages and the search for Crispr-Cas3 inhibitors

• Grant number: 25/04443-1
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: February 29, 2028
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Shaker Chuck Farah
• Grantee: Arthur Oliveira Pereira
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 21/10577-0 - Biology of Bacteria and Bacteriophages Research Center, AP.CEPID

Abstract

Citrus canker-causing phytopathogenic bacteria of the order Xanthomonadales, such as Xanthomonas citri and Xylella Fastidiosa, are a significant threat to citrus farming. Brazilian native biomes, such as the Atlantic Forest, have several uncharacterized native microorganisms that can be exploited. Despite the absence of documented occurrences of bacteria belonging to this order in the Atlantic Forest, the study aims to explore native phages as potential biocontrol agents for them. The main objective is divided into two strands: to build a library of native phages against bacteria belonging to the Xanthomonadales and to induce resistance against the phage ¿Xacm4-11 in X. citri, using the CRISPR/Cas3 system. The specific objectives include the isolation and characterization of phages from environmental samples of native Brazilian biomes, the evaluation of their infectivity against different strains of Xanthomonadales, and the screening of compounds that can inhibit the CRISPR/cas3 system by HTS, allowing reinfection by phages.This project aims to improve our understanding of the interactions between bacteria of the order Xanthomonadales and their bacteriophages, and to build a bacteriophage library for future work, while leveraging the CRISPR system as an innovative tool to control resistance in phytopathogenic bacteria against bacteriophages.