An unknown source of Micrococcus luteus bacteremia

Micrococcus luteus is a common organism in the human skin flora. It is an uncommon cause of pathogenic bloodstream infections, which occur mostly in immunocompromised patients. We report the clinical course of an 82-year-old man who underwent complex management of multiple diverticular abscesses and had three serial positive blood cultures for M. luteus. Despite treatment with vancomycin, the patient ultimately died due to septicemia secondary to mixed gastrointestinal flora and M. luteus. A source this infection was never definitely identified.