Enterococcus faecalis Demonstrates Pathogenicity through Increased Attachment in an Ex Vivo Polymicrobial Pulpal...

Area of Science:

• Oral microbiology
• Dental research
• Infectious diseases

Background:

• Streptococcus anginosus and Enterococcus faecalis are key pathogens in dental abscesses and endodontic failure.
• Understanding polymicrobial infections is crucial for effective endodontic treatment and managing pulpitis.

Purpose of the Study:

• To investigate the host response to polymicrobial pulpal infections involving S. anginosus and E. faecalis.
• To determine the role of bacterial attachment and specific species in driving inflammatory responses within the dental pulp.

Main Methods:

• An ex vivo rat tooth model was used to inoculate tooth slices with S. anginosus and E. faecalis alone or in co-culture.
• Bacterial attachment was quantified, and host response was assessed via cell viability counts, RT-qPCR for inflammatory markers (TNF-α, IL-1β), and immunohistochemistry.

Main Results:

• Both single and polymicrobial infections significantly reduced pulp cell viability.
• E. faecalis exhibited higher attachment levels than S. anginosus, with a strong affinity for pulpal vasculature.
• E. faecalis infection, particularly in polymicrobial settings, led to the greatest increase in TNF-α and IL-1β expression, localized to vasculature and odontoblasts.

Conclusions:

• E. faecalis plays a significant role in driving inflammation in polymicrobial dental pulp infections.
• The pathogenicity of E. faecalis in pulpitis appears linked to its superior ability to adhere to pulpal vasculature, rather than solely relying on secreted factors.