Corynebacterium jeikeium

Outside of C. diphtheriae, probably one of the most important of the Corynebacterium species is Corynebacterium jeikeium:

Corynebacterium jeikeium (formally known as CDC Group JK) has been implicated in sepsis and endocarditis for over forty years. While technically not emerging, it is important to mention the isolation of this organism because:

• It is highly virulent
• It is a multi-drug-resistant species
• It should not be considered a contaminant when isolated from bacterial cultures of patients that are immunocompromised, neutropenic, have an intravascular catheter, have a hematologic malignancy, have a prolonged hospital stay, or impaired skin integrity.

C. jeikeium can cause cutaneous manifestations and pulmonary infiltrates due to bacteremia but pneumonia tends to be an independent process. According to Gupta et al.'s review, there is a high mortality rate (up to 33%) even with treatment.¹⁴

C. jeikeium is a lipophilic species that is small, nonhemolytic, grayish-white, and glistening on sheep blood agar after 24 hours at 37ºC. Tween 80 will enhance growth and the organism only ferments glucose and galactose sugars.