651. Clinical Characteristics and Susceptibility Profiles of Infections Due to Elizabethkingia

Abstract Background Elizabethkingia spp. are non-enteric, gram-negative bacilli that are ubiquitous in environment. It has recently been identified as a causative pathogen in hospital outbreaks of life-threatening bloodstream infections in the Midwestern United States. Methods Retrospective electronic medical record review was performed for patients with Elizabethkingia spp. isolated from any site between November 2011 and September 2020 at our tertiary academic medical center. Antimicrobial susceptibilities are performed using Wadsworth agar dilution method. Results Fifteen cases with Elizabethkingia spp. were included. Ten patients (66.7%) were male and fourteen (93.3%) were Caucasian. The median age was 58 years (IQR 42-67). Four patients had diabetes mellitus, with two of these having end-organ damage (nephropathy, neuropathy, or retinopathy). Five patients had a tracheostomy, two patients had a history of lung transplantation, and four patients had active malignancy at the time of diagnosis (table 1). The most common clinical syndrome was respiratory infection (n=6), followed by catheter-related bloodstream infection (CRBSI) (n=4). Three patients were considered to be asymptomatically colonized. Five patients (33.3%) died, one of which was attributable to Elizabethkingia infection. A total of 55 isolates from all sites were available from the fifteen patients. The most common site of isolation was respiratory tract (23/55, 41.8%). In total, 33 of 55 isolates had polymicrobial growth, with the highest rate occurring in respiratory tract specimens (Table 2). A total of 23 clinical isolates were included in tabulation of antimicrobial susceptibility profiles; except for aztreonam (n=13). 95.7% of Elizabethkingia isolates were susceptible to trimethoprim-sulfamethoxazole, followed by levofloxacin and piperacillin-tazobactam (87% and 73.9%, respectively). All isolates were uniformly resistant to amikacin, aztreonam, and tobramycin (Table 3). Conclusion Elizabethkingia spp. can result in respiratory, bloodstream, and sinus infections especially in patients with active malignancy and tracheostomy. Amongst tested antimicrobials, trimethoprim-sulfamethoxazole showed the most favorable susceptibility profile (Figure 1). Figure 1. AN, amikacin; ATM, aztreonam; CAZ, ceftazidime; CIP, ciprofloxacin; FEP, cefepime; GM, gentamicin; LVX, levofloxacin; MEM, meropenem; NN, tobramycin; SXT, sulfamethoxazole/trimethoprim; TZP, piperacillin/tazobactam. Disclosures All Authors: No reported disclosures