Loss of Ethanolamine Utilization in Enterococcus faecalis Increases Gastrointestinal Tract Colonization

Area of Science:

• Microbiology
• Gut Microbiome Research
• Bacterial Pathogenesis

Background:

• Enterococcus faecalis is both a common gut bacterium and a nosocomial pathogen.
• The human gut contains high concentrations of ethanolamine (EA).
• EA catabolism via eut genes is known to aid colonization by other enteric pathogens.

Purpose of the Study:

• To investigate the role of ethanolamine utilization (eut) genes in E. faecalis gut colonization.
• To determine if EA catabolism promotes or inhibits E. faecalis colonization in a competitive gut environment.

Main Methods:

• Construction and testing of eut mutants of E. faecalis.
• Utilizing a murine model for gastrointestinal tract competition studies.
• Comparing colonization ability of wild-type E. faecalis against its eut mutants.

Main Results:

• E. faecalis eut mutants demonstrated superior colonization compared to the wild-type strain in the murine gut.
• The ability to utilize ethanolamine was found to negatively impact E. faecalis colonization.
• This finding contrasts with the known role of EA utilization in other gut pathogens.

Conclusions:

• Ethanolamine utilization is not universally beneficial for gut bacterial colonization.
• The eut genes in E. faecalis appear to hinder, rather than promote, its ability to colonize the gut.
• Understanding factors affecting colonization is crucial, especially for opportunistic pathogens like E. faecalis.