The extracellular thioredoxin Etrx3 is required for macrophage infection in Rhodococcus equi

Area of Science:

• Veterinary microbiology
• Bacterial pathogenesis
• Redox homeostasis

Background:

• Rhodococcus equi is an intracellular veterinary pathogen with increasing antibiotic resistance.
• Genes regulating redox homeostasis are potential targets for novel anti-infective strategies.

Purpose of the Study:

• To investigate the role of extracellular thioredoxin (Etrx3) in R. equi's resistance to phagocytosis and oxidative stress.

Main Methods:

• Generated an etrx3-null mutant of R. equi.
• Assessed intracellular survival of the mutant and complemented strains within macrophages.
• Evaluated susceptibility to sodium hypochlorite.

Main Results:

• The etrx3-null mutant showed significantly reduced survival within macrophages.
• Complementation with the etrx3 gene restored intracellular survival.
• Deletion of etrx3 led to increased susceptibility to sodium hypochlorite.

Conclusions:

• Etrx3 is essential for R. equi's intracellular survival in macrophages.
• Etrx3 plays a critical role in protecting R. equi against oxidative stress, specifically sodium hypochlorite.
• Etrx3 represents a promising target for developing new therapies against R. equi infections.