Rhizobium radiobacter Sepsis Linked to Munchausen Syndrome

Abstract

Rhizobium (formerly Agrobacterium) radiobacter is an opportunistic, usually saprophytic, Gram-negative bacillus most often found in agricultural soil. Isolation from blood has been reported, most often in hospitalized patients with malignancy or HIV-associated immunosuppression who present with catheter- or medical device-related febrile neutropenia. Treatment involves removal of the catheter or implanted medical device. We report a case of a 27-yearold African-American woman, presenting with complaints of fever and generalized body pain due to homozygous sickle cell disease. Two sets of blood cultures (four bottles) were positive for a Gram-negative bacterium. Convex, smooth, shining colonies 1 mm in diameter grew on sheep blood agar and chocolate agar at 48 hours. Mucoid white colonies grew on MacConkey agar within 48 hours, consistent with a lactose nonfermenter. A screening oxidase test was positive. Identification of R radiobacter was made using multiple biochemical tests in the Rapid NF Plus system (Remel, Thermo Scientific). The patient was given antibiotics: Levaquin 750 mg orally daily for 2 weeks plus posaconazole 200 mg orally twice daily for 2 weeks for her concomitant fungal infection. However, treatment may have been complicated due to noncompliance. A syringe was found in the patient's possession and when questioned, the patient admitted to injecting feces and urine into her central line. Growth of an unusual organism in the blood of a patient without usual risk factors for infection due to R radiobacter should raise a suspicion of a factitious psychiatric disorder, also known as Munchausen syndrome, with self-injection of foreign material.