Citrobacter braakii Bacteremia: Case Report and Review of the Literature

Bacteremia is frequently caused by gram-positive organisms such as Staphylococcus aureus or β hemolytic streptococci. While there is adequate information for the diagnosis and management of these common bacteria, less information is available to address bacteremia that is caused by uncommon bacteria such as Citrobacter. Citrobacter species are gram-negative bacilli that have been noted to cause infections in immune compromised patients. The re-speciation of Citrobacter by its varied genetic composition has produced 11 distinct species. While C. braakii is part of the genome species 6 of the previous Citrobacter freundii complex, there is a lack of definitive research on the subject of Citrobacter bacteremia caused by lesser- known species. We report an unusual case of Citrobacter braakii bacteremia in a patient with multiple comorbidities that presented to the hospital with cellulitis and pleural effusion. Blood cultures grew Citrobacter braakii. Despite good response to antibiotic treatment, the patient’s infection proved to be persistent and he succumbed to the cirrhosis of the liver and subsequent renal failure. Multiple and fatal underlying disease processes seem to worsen the likelihood of recovery from unusual infections. We believe our case report can add to the limited data available for C. braakii.