Aerococcus

Microbiology

• Gram-positive coccus
• Notable species
  • Aerococcus urinae, which causes urinary tract infections
  • Aerococcus sanguinicola, causes UTIs, but sometimes a contaminant
  • Aerococcus viridans, often a contaminant
• Presumed resistance in vivo to TMP-SMX, even though it may appear susceptible in vitro
  • It can acquire folate from the host's urine, counteracting the antibiotic

Clinical Manifestations

• A. urinae causes UTI and endocarditis (often following UTI in older men)

Management

• Penicillin or ampicillin
• ± aminoglycoside (for synergy, based on in vitro studies)
• Can be susceptible to ceftriaxone, though MICs are higher than for penicillin

Further Reading

• Aerococcus: an increasingly acknowledged human pathogen. Clin Microbiol Infect. 2016 Jan;22(1):22-27. doi: 10.1016/j.cmi.2015.09.026. PMID: 26454061.