1579. Burkholderia Returns: Are Two Drugs Better or Back to Bactrim?

Background Trimethoprim-sulfamethoxazole (T/S) and levofloxacin are considered first line agents for the treatment of Burkholderia cepacia complex (Bcc). Combination therapy (CT) is frequently utilized despite limited clinical evidence supporting this. The objective of this study is to compare outcomes associated with different regimens for the treatment of Bcc infections. Methods This is a retrospective cohort study in non-cystic fibrosis adult patients with infection caused by Bcc from 2015 to 2019. The primary outcome is the composite of overall treatment failure defined as clinical failure, microbiologic failure, or mortality at 30 days. Secondary outcomes include mortality, clinical failure, microbiological failure, development of resistance, recurrence, and safety. Comparisons were performed using Chi-squared or Fischer’s exact test for categorical variables and Student’s t test or the Mann-Whitney U test for continuous variables, as appropriate. Multivariable logistic regression analysis was used to identify independent risk factors for overall treatment failure. Results Sixty-eight patients were included, 50 (74%) received monotherapy (MT) and 18 (26%) received CT. MT regimens included meropenem (n=19), ceftazidime (n=15), T/S (n=10), and other (n=6). Various combination regimens were utilized. MT recipients were significantly older, more likely to have renal disease, less likely to have an immunosuppression, and had a higher severity of illness. The most common site of infection was respiratory (78%). No difference was found for overall treatment failure between MT and CT (36.0% vs. 38.9%; p=0.947). No differences were found in the secondary outcomes (Table 1). Overall treatment failure did not differ by treatment regimens utilized. On multivariable analysis controlling for age, renal disease, CCI, immunosuppression, ICU admission, SOFA score, and receipt of MT, only SOFA score was associated with treatment failure [OR 1.43 (95% CI 1.15 to 1.77); p=0.001] and not MT [OR 1.22 (95% CI 0.25 to 5.97); p=0.808]. Table 1: Treatment Outcomes – MT versus CT Conclusion There were no differences in outcomes between MT and CT groups for the treatment of Bcc infection. Treatment outcomes appeared to be driven primarily by disease severity. Additional studies are needed to identify the optimal treatment regimens. Disclosures All Authors: No reported disclosures