Pangenome analysis and virulence profiling of Streptococcus intermedius

Area of Science:

• Microbiology
• Genomics
• Infectious Diseases

Background:

• Streptococcus intermedius is a commensal bacterium with pathogenic potential.
• It is associated with serious infections like abscesses and bacteremia.
• Genomic sequencing has advanced understanding of bacterial virulence.

Purpose of the Study:

• To investigate the relationship between specific virulence genes and clinical manifestations of Streptococcus intermedius infections.
• To compare the genomes of 27 S. intermedius strains from diverse infections.

Main Methods:

• Whole-genome sequencing of 27 S. intermedius strains.
• Pangenome analysis to assess genomic diversity and identify core and accessory genes.
• Principal Component Analysis (PCA) to correlate virulence gene presence/absence with clinical data.

Main Results:

• The S. intermedius pangenome is characterized as 'open' with significant genomic diversity.
• A core virulome of 70 genes and 78 unique virulence markers were identified.
• Specific genes (sda, LAP, cps4E) were linked to brain/broncho-pulmonary infections, while others (fbp54, cap8D, cpsB) were associated with liver/abdominal abscesses.

Conclusions:

• Distinct genetic profiles of virulence genes in S. intermedius correlate with specific disease types.
• These findings offer insights into S. intermedius pathogenesis.
• Identified genetic markers may serve as targets for future diagnostic tools.