P-2257. <i>Pseudomonas aeruginosa</i> and other Bacterial Infections After Lung Transplant: Risk Factors, Airway Stenosis and other Clinical Outcomes

Abstract Background Pseudomonas aeruginosa (PsA) and other bacterial infections after lung transplant can lead to worse patient outcomes. The aim of this study was to investigate whether isolation of microbial pathogens post-lung transplantation increased the risk of airway stenosis requiring bronchoscopic interventions. Table 1Table 1.Demographic, donor/recipient characteristics, peri-operative/post-operative characteristics and outcomes. Methods A single-center retrospective study of lung transplant recipients (LTR) between January 2017 and October 2023 was performed. Our center performs routine surveillance bronchoscopies at 1, 3, 6 and 12 months. Donor/recipient characteristics, microbiologic data, bronchoscopy findings and interventions, and 1-year outcomes were analyzed. Results In this 6.8-year study period, 327 subjects underwent lung transplant with survival greater than 30 days. The most common indication for lung transplant was restrictive lung disease. 64 (20%) had PsA infections, 77 (23%) had non-PsA bacterial infections (infect), and 186 (57%) did not have a bacterial infection within 6-months post-transplant. Recipient and donor characteristics were similar among the cohorts. A greater proportion of the PsA and infect cohorts required dialysis and mechanical ventilation and/or ECMO for &amp;gt;48 hours and had a longer index hospitalization than the uninfected cohort [Table 1]. A greater proportion of the PsA and infect cohorts developed airway stenosis requiring bronchial intervention (22% vs 17% vs 2%, p=&amp;lt; 0.001). The median time to first infection post-transplant occurred prior to the development of stenosis (72 vs 112 days; 52 vs 110 days). 44% of LTR with PsA growth had fluoroquinolone resistance on the initial culture. Rates of rejection and 1-year survival were not statistically different among the cohorts. Conclusion PsA and other bacterial infections within the first 6-months post lung transplantation led to a higher incidence of airway stenosis requiring bronchial intervention but was not associated with increased mortality or rejection at 1-year. The impact of treating bacterial colonization and other strategies to minimize post-transplant bacterial infections and decreasing the occurrence and time to airway stenosis needs further study. Disclosures All Authors: No reported disclosures