152. Brevibacterium species: Case Series and Literature Review of an Emerging Opportunistic Cause of Bloodstream Infections

BACKGROUND: Brevibacterium species are non-motile, catalase-positive, obligate aerobic gram-positive bacilli. Colonies are yellow to gray-white, non-hemolytic, smooth, 6.5% sodium chloride tolerant. B. fermentans post neurosurgical meningitis was first described in 1969 in an infant. B. casei remains the most commonly isolated species (Table 4). The most commonly reported syndromes are bloodstream infections (BSIs) and endocarditis. Despite these reports, this organism continues to be listed on CDC’s NHSN commensal database. METHODS: Isolates of Brevibacterium from clinical samples at Mayo Clinic, Rochester from January 1, 2014 to December 31, 2018 were identified. Charts were reviewed to determine patient demographics, immune status, source of culture, comorbidities, antibiotic susceptibility test (AST), length of stay (LOS) in hospital and intensive care unit (ICU), and mortality. Likelihood ratio (L-R) and Pearson correlation coefficient (PCC) of nominal data were calculated using the Chi-square test and Fischer exact test (FET). We defined statistical significance as P ≤ 0.05. RESULTS: We identified 48 isolates from 45 unique patients, 46% were females. Distribution of age, hospital and ICU LOS, and time to culture growth, and AST data are shown in Table 1. 15.5% patients received allogeneic or autologous stem cell (SCT), or solid-organ transplant (SOT) recipients. 89% cultures were from sterile sources and 68.75% were blood cultures. Of these, 63.64% were monomicrobial. 62% of isolates identified to species level were B. casei. 5 patients were treated; an additional 10 received active antibiotics for other indications. Statistically significant variables are reported in Tables 2 and 3. Thirty-day mortality was 13%. This was higher in patients with bacteremia (L-R: 5.3 [P = 0.02]) but FET was not statistically significance (P = 0.15). CONCLUSION: Accurate diagnosis of Brevibacterium may require molecular techniques. At our center, SCT or SOT recipient status and recent chemotherapy were associated with bacteremia. In these patients, this organism could represent an opportunistic cause of BSI. AST data suggest that Vancomycin offers a reasonable empiric treatment option. Additional data are needed to further define host populations in whom this organism presents pathogenicity. [Image: see text] [Image: see text] [Image: see text] [Image: see text] DISCLOSURES: All authors: No reported disclosures.