Liver abscess with Citrobacter koseri bacteremia.

Citrobacter koseri is a rare cause of liver abscess with two reported cases in diabetic patients. We report a rare case of C. koseri liver abscess with C. koseri bacteremia in an elderly male with chronic kidney disease. He presented vomiting and weakness without any other signs. He was diagnosed with liver abscess by ultrasound, and blood culture showed C. koseri growth. The patient was treated effectively with a course of antibiotics and drainage. When C. koseri is isolated in patients with comorbidity, such as chronic kidney disease, we should consider the possibility of abscess including liver abscess and utilize a combined treatment of drainage and course of antibiotics for mixed infection.