Insights into Dynamic Polymicrobial Synergy Revealed by Time-Coursed RNA-Seq.

Area of Science:

• Microbiology
• Oral Health
• Bacterial Pathogenesis

Background:

• Polymicrobial communities drive synergistic pathogenicity in bacterial infections.
• Periodontitis is a chronic inflammatory disorder caused by multispecies bacterial communities.
• Porphyromonas gingivalis and Streptococcus gordonii exhibit polymicrobial synergy in disease models.

Purpose of the Study:

• To investigate the dynamic transcriptional changes of P. gingivalis in a polymicrobial consortium with S. gordonii.
• To understand the molecular basis for increased pathogenicity in dual-species bacterial communities.

Main Methods:

• Time-course RNA sequencing (RNA-Seq) was employed to analyze P. gingivalis gene expression.
• A model consortium of P. gingivalis and S. gordonii was used.
• Differential gene expression analysis was performed.

Main Results:

• Genes for virulence factors (adhesins, Type IX secretion, TPR proteins) showed increased mRNA levels in dual-species cultures.
• Genes for conjugation systems and most stress responses were downregulated.
• Expression of oxidative stress response genes (OxyR regulon) increased, suggesting adaptation to S. gordonii-produced peroxide.

Conclusions:

• P. gingivalis exhibits transcriptional adaptation to polymicrobial oral environments.
• This adaptation leads to enhanced pathogenic potential.
• Findings support evolutionary adaptation of P. gingivalis to synergistic oral microbial communities.