Rhodococcus equi

Background

Microbiology

• Facultative intracellular, non-spore-forming, Gram-positive, weakly acid-fast coccobacillus
• Found in dry and dusty soil
• Makes red pigment, hence the name
• Member of the actinomycetes group

Epidemiology

• Infects domesticated animals
  • Horses, and in foals it causes pneumonia
  • Goats
  • Pigs
  • Sheep
  • Cattle
• Can infect immunocompromised people (HIV, etc)

Clinical Manifestations

• Necrotizing pneumonia is usual presentation, as well as nodules, cavitation, pleural effusion, and lung abscess
• Specifically in immunocompromised patients, it can cause a cavitary lung disease and is on the differential with mycobacteria and nocardiosis

Management

• Treatment usually 6 months or longer