Multiple Liver Abscesses due to Citrobacter koseri: An Extremely Rare Presentation

Abstract

Pyogenic liver abscess (PLA) of the liver is relatively rare. Citrobacter is a very rare cause of liver abscess. We report a case of multiple liver abscess due to Citrobacter koseri. This is the 3rd reported case with liver abscess and Citrobacter koseri. A 61 years old woman presented to the ER with abdominal pain, fever, and progressive jaundice of 2 weeks duration. She had history of NHL which presented with biliary obstruction that required biliary stent placement 3 years back. The biliary sent was not removed as the patient was lost to follow up. She was hypotensive requiring IV fluid boluses and pressor support. Laboratory studies: white blood count 25.16 k/μL, serum creatinine 1.3 mg/dl, total bilirubin 2.5 (mg/dL), direct bilirubin 2.0 (mg/dL), alkaline phosphatase 345 (IU/L), ALT 57 (IU/L), and AST 152 (IU/L). U/S of the abdomen showed extensive intrahepatic biliary dilatation and multiple hypoechoic structure in the liver. CT of the abdomen showed lesions scattered throughout the liver suscpecious of abscesses. Blood culture was positive for Citrobacter koseri. Patient underwent liver biopsy with aspiration pus and three core biopsies. Citrobacter koseri was isolated from the pus. Pathology was negative for malignancy. The patient was treated with IV Imipenem and oral ciprofloxacin for 6 weeks and had remarkable clinical improvement. Follow up imaging studies with U/S showed complete resolution of the abscesses. Pyogenic Liver Abscesses due to Citrobacter koseri is a rare infection; we are aware of only two reported cases in the literature. Therefore, little is known about Citrobacter liver abscess in terms of incidence, associated underlying diseases, and outcome. Treatment of citrobacter koseri infection in general could be complicated by rapid development of resistance particularly if monotherapy with a cephalosporin is started. This is mainly due to due to high level of beta lactamase and cephalosporinase production. Thus, combination therapy is recommended for initial empirical treatment of Citrobacter koseri infection.