Galleria mellonella as a model for studying Enterococcus faecium host persistence.

Area of Science:

• Microbiology
• Infectious Diseases
• Pathogen Research

Background:

• Enterococcus faecium is an opportunistic pathogen causing global outbreaks.
• Understanding hospital-adapted E. faecium colonization and persistence is crucial.
• Existing models for studying E. faecium virulence factors are limited.

Purpose of the Study:

• To establish Galleria mellonella as a nonmammalian model for assessing E. faecium host persistence.
• To evaluate the colonization abilities of various E. faecium strains within G. mellonella.
• To investigate the role of sodA in E. faecium survival against host defenses.

Main Methods:

• Infection of Galleria mellonella larvae with ten different E. faecium strains (hospital-adapted, commensal, animal isolates, and sodA-deficient).
• Assessment of bacterial loads within G. mellonella post-infection to evaluate colonization and multiplication.
• Comparison of E. faecium virulence and survival against E. faecalis in a killing assay.

Main Results:

• E. faecium strains exhibited lower lethality in Galleria compared to E. faecalis.
• Two hospital-adapted E. faecium isolates demonstrated enhanced colonization capabilities in the G. mellonella model.
• Inactivation of sodA significantly reduced E. faecium survival against Galleria's immune defenses.

Conclusions:

• Galleria mellonella serves as a suitable and convenient model for studying E. faecium host survival.
• The study highlights the importance of sodA in E. faecium's ability to overcome host defenses.
• This model facilitates research into virulence factors contributing to E. faecium colonization.