Transcriptomic analysis of Streptococcus agalactiae periprosthetic joint infection

Area of Science:

• Microbiology
• Infectious Diseases
• Genomics

Background:

• Streptococcus agalactiae periprosthetic joint infection (PJI) is less common than staphylococcal PJI but represents a significant clinical challenge.
• Invasive S. agalactiae infections, including PJI, necessitate a deeper understanding of their pathogenesis.

Purpose of the Study:

• To perform transcriptomic analysis of S. agalactiae PJI using sonicate fluid from explanted joints.
• To compare gene expression profiles between S. agalactiae in PJI and in vitro conditions.
• To identify potential therapeutic targets for S. agalactiae PJI.

Main Methods:

• RNA sequencing (RNA-seq) was employed for transcriptomic analysis.
• Fluid from sonicated explanted arthroplasties of PJI patients was used.
• Gene expression data was compared between PJI sonicate fluid and in vitro grown S. agalactiae (strain NEM316).

Main Results:

• A total of 227 differentially expressed genes were identified (164 upregulated, 63 downregulated).
• Enrichment analysis indicated significant upregulation of genes involved in mobilome and inorganic ion transport (nickel, copper, zinc).
• The cyl operon genes, encoding β-hemolysin/cytolysin, showed consistently high expression in PJI samples.

Conclusions:

• The study provides novel insights into the pathogenesis of S. agalactiae PJI.
• Upregulated virulence factors like the cyl operon and ion transport mechanisms are key in PJI.
• These findings may guide the development of novel therapeutics and vaccines against invasive S. agalactiae infections.