New Insights into the Enterococcus faecium and Streptococcus gallolyticus subsp. gallolyticus Host Interaction...

Area of Science:

• Microbiology
• Infectious Diseases
• Gastroenterology

Background:

• Enterococcus faecium and Streptococcus gallolyticus (Lancefield Group D) are opportunistic pathogens.
• E. faecium causes nosocomial bacteremia; S. gallolyticus is linked to colorectal cancer patient endocarditis.
• Both pathogens originate endogenously, translocating through the intestinal barrier.

Purpose of the Study:

• To compare the adhesion, invasion, and translocation abilities of E. faecium and S. gallolyticus isolates.
• To investigate biofilm formation on different surfaces.
• To gain insights into the early pathological processes of infection.

Main Methods:

• Utilized an in vitro Caco-2 cell model.
• Studied adhesion, invasion, and translocation of 6 E. faecium and 4 S. gallolyticus isolates.
• Assessed biofilm formation on polystyrene, collagen I, and collagen IV.

Main Results:

• E. faecium exhibited significantly higher translocation and adhesion than S. gallolyticus, destabilizing the intestinal monolayer.
• Specific E. faecium isolates (Efm106, Efm121, Efm113) showed superior translocation.
• Both species preferred collagen IV for biofilm formation, with S. gallolyticus forming more compact structures.

Conclusions:

• High translocation ability of certain E. faecium clones may contribute to increased bacteremia rates.
• Compact biofilm formation by S. gallolyticus could relate to vegetation in endocarditis.
• Understanding these mechanisms aids in predicting and preventing opportunistic infections.