Micrococcus/Macrococcus spp

• M. flavus
• M. luteus
• M. lylae

• Gram positive spherical cocci in tetrads and clusters (aerobic)

Clinical Significance

These organisms are widespread in nature and are part of commensal skin flora. 

Micrococcus species have been associated with opportunistic infections including septicemia, endocarditis, central nervous system infections (brain abscesses, meningitis), peritonitis, septic arthritis, and pneumonia.

Infections are typically related to medical devices, indwelling catheters or invasive procedures, often in immunocompromised patients.

M. luteus is associated with the bad odour of sweat. In immunocompromised individuals (especially HIV patients), it can cause chronic pruritic skin eruptions/infections.

Usual Susceptibility Pattern

This organism is typically susceptible to penicillin, vancomycin, linezolid, tetracyclines, rifampin, and clindamycin.

Some strains exhibit cloxacillin, cephalosporin, and macrolide resistance.