Gemella

Background

Microbiology

• Genus of Gram-positive cocci, in pairs, tetrads, clusters, or sometimes small chains
• Facultative anaerobic
• Decolorize easily on Gram stain, appearing Gram-negative
• Siderophilic
• Member of oral flora
• Includes 6 species that are pathogenic to humans:
  • Gemella haemolysans
  • Gemella morbillorum
  • Gemella bergeri
  • Gemella sanguinis
  • Gemella assacharolytica
  • Gemella taiwanensis
• And 3 that are not pathogenic: Gemella parahaemolysans, Gemella palitacanis, and Gemella cuniculi

Clinical Manifestations

• Includes endocarditis, brain abscesses, bone and joint infections, liver abscesses