Identification of a PadR-type regulator essential for intracellular pathogenesis of Burkholderia pseudomallei

Area of Science:

• Microbiology
• Pathogen Biology
• Genetics

Background:

• Burkholderia pseudomallei (Bp) causes melioidosis, a tropical disease with diverse clinical presentations.
• Bp is a facultative intracellular pathogen with a complex lifecycle within host cells.

Purpose of the Study:

• To identify and characterize transcriptional regulators involved in Bp's intracellular lifecycle.
• To elucidate the function and regulon of the identified transcriptional regulator, BP1026B_II1198.

Main Methods:

• Deletion mutant construction and virulence assessment in cell culture (RAW264.7) and animal models (BALB/c mice).
• RNA-sequencing (RNA-seq) to determine global gene expression changes.
• Chromatin immunoprecipitation sequencing (ChIP-seq) to identify DNA binding sites of BP1026B_II1198.
• Transposon mutagenesis to analyze the contribution of regulated genes to pathogenesis.

Main Results:

• A novel transcriptional regulator, BP1026B_II1198, was identified and found to be differentially expressed during host cell transit.
• A BP1026B_II1198 deletion mutant exhibited attenuated virulence in both macrophage and mouse infection models.
• RNA-seq and ChIP-seq analyses revealed the regulon of BP1026B_II1198, identifying specific target genes on chromosome II.
• Genes regulated by BP1026B_II1198 were confirmed to contribute to Bp pathogenesis in murine macrophages.

Conclusions:

• BP1026B_II1198 plays a significant role in Bp intracellular infection and virulence.
• The study elucidates a part of the complex regulatory network governing Bp's host-pathogen interactions.
• Understanding BP1026B_II1198 and its regulon provides insights into melioidosis pathogenesis and potential therapeutic targets.