274. Legionella bozemanii (Fluoribacter bozemanae) Brain Abscess in a Renal Transplant Recipient

Abstract Background Legionnaires’ disease is a potentially fatal multi-system disease caused by Legionella species. However, extra-pulmonary Legionella disease is rare and is typically associated with Legionella species other than L. pneumophila in immunocompromised patients. Methods We present a 55-year-old immunocompromised male with history of living-related renal transplant secondary to IgA nephropathy (day 0) which was complicated by T-cell mediated rejection requiring anti-thymocyte globulin and elotuzumab (day 130). Results Patient was hospitalized on day 184 with community-acquired pneumonia and treated with piperacillin-tazobactam and azithromycin. Three weeks later (day 214), he presented with new-onset seizures and was found to have a frontal brain abscess on MRI. His clinical course and brain imaging worsened despite undergoing multiple operative drainage procedures, placement of an extra ventricular drain, and receiving broad-spectrum antimicrobials. L. bozemanii was first identified from cerebrospinal fluid (CSF) on buffered charcoal yeast extract (BCYE) agar from day 240 and was also later confirmed by 16S rRNA sequencing. Susceptibilities were unavailable due to poor organism growth. Of note, his allergy history was significant for rash with ciprofloxacin and levofloxacin. Based on the low severity of the allergic reaction and need for central nervous system penetration, moxifloxacin 400 mg intravenously every 24 hours was initiated on day 244 in addition to broad-spectrum antibiotics. Subsequent CSF cultures were positive for L. bozemanii until the CSF culture on day 250. Due to poor clinical response, azithromycin and intrathecal polymyxin B were added for salvage therapy on day 255. His neurological status continued to worsen and he eventually succumbed to his illness on day 262. 08/31/20 MRI Brain New solitary ring-enhancing lesion with significant surrounding vasogenic edema within the anterior right frontal lobe. 09/23/20 MRI Brain Post-Surgical right frontal lobe with edema, persistent cerebritis, and mass effect on the lateral ventricles. Fluoribacter Bozemanae Formerly known as Legionella bozemanii, an intracellular GNR grown on BCYE. Conclusion We present a diagnostically challenging case of L. bozemanii brain abscess in an immunocompromised patient. To our knowledge, this is the first case of culture proven L. bozemanii brain abscess in the literature. Considering the fastidious growth of the organism, fatal nature of the infection, and narrow therapeutic profile, Legionella infection should be considered in a multi-system disease in immunocompromised patients. Disclosures Wesley Kufel, PharmD, Melinta (Grant/Research Support)Merck (Grant/Research Support)Theratechnologies, Inc. (Advisor or Review Panel member)

Background. Although trimethoprim-sulfamethoxazole (TMP-SMX) has consistently demonstrated significant interindividual variability, therapeutic drug monitoring is used to optimize dosing and avoid adverse reactions that may contribute to treatment interruption. While data exists on the use of SMX level monitoring in pneumocystis, there is a lack of data in SMX serum monitoring utility for invasive Nocardia infections.
Methods. We retrospectively reviewed adults who received TMP-SMX to treat nocardial brain abscess (BA) and underwent SMX testing level from January 2010 to December 2020.
Conclusion. Patients with SMX serum level monitoring are more likely to be on HD, during the induction phase and among those with higher and more frequent dosing. About half of patients with SMX levels >150 mcg/mL experienced drug toxicity; however, SMX levels did not impact patient outcome and length of treatment.
Disclosures. Background. Infection of the central nervous system is a severe and fatal disease. Causative agents include bacteria, viruses or fungi. Intracellular bacteria are not only overlooked, but also underdiagnosed. We aimed to study the clinical, laboratory and evolutionary features of neurological involvement caused by intracellular bacteria.
Methods. We conducted a retrospective study including all patients hospitalized in the infectious disease department for neurological involvement caused by intracellular bacteria between 1995 and 2020. The diagnosis was confirmed by serology.
Conclusion. Intracellular bacteria including Brucella, Rickettsia and Mycoplasma species should be considered in front of neurological symptoms. Meningitis with lymphocytic pleocytosis was the most common clinical presentation. An early diagnosis followed by the adequate treatment might avoid complications and death.
Disclosures. All Authors: No reported disclosures Background. Legionnaires' disease is a potentially fatal multi-system disease caused by Legionella species. However, extra-pulmonary Legionella disease is rare and is typically associated with Legionella species other than L. pneumophila in immunocompromised patients.

Legionella bozemanii (Fluoribacter bozemanae) Brain Abscess in a Renal
Methods. We present a 55-year-old immunocompromised male with history of living-related renal transplant secondary to IgA nephropathy (day 0) which was complicated by T-cell mediated rejection requiring anti-thymocyte globulin and elotuzumab (day 130).
Results. Patient was hospitalized on day 184 with community-acquired pneumonia and treated with piperacillin-tazobactam and azithromycin. Three weeks later (day 214), he presented with new-onset seizures and was found to have a frontal brain abscess on MRI. His clinical course and brain imaging worsened despite undergoing multiple operative drainage procedures, placement of an extra ventricular drain, and receiving broad-spectrum antimicrobials. L. bozemanii was first identified from cerebrospinal fluid (CSF) on buffered charcoal yeast extract (BCYE) agar from day 240 and was also later confirmed by 16S rRNA sequencing. Susceptibilities were unavailable due to poor organism growth. Of note, his allergy history was significant for rash with ciprofloxacin and levofloxacin. Based on the low severity of the allergic reaction and need for central nervous system penetration, moxifloxacin 400 mg intravenously every 24 hours was initiated on day 244 in addition to broad-spectrum antibiotics. Subsequent CSF cultures were positive for L. bozemanii until the CSF culture on day 250. Due to poor clinical response, azithromycin and intrathecal polymyxin B were added for salvage therapy on day 255. His neurological status continued to worsen and he eventually succumbed to his illness on day 262. 08/31/20 MRI Brain