Epidemiology and outcomes of multidrug-resistant bacterial infection in non-cystic fibrosis bronchiectasis

PURPOSE: Multidrug-resistant (MDR) bacteria impose a considerable health-care burden and are associated with bronchiectasis exacerbation. This study investigated the clinical outcomes of adult patients with bronchiectasis following MDR bacterial infection.

METHODS: From the Chang Gung Research Database, we identified patients with bronchiectasis and MDR bacterial infection from 2008 to 2017. The control group comprised patients with bronchiectasis who did not have MDR bacterial infection and were propensity-score matched at a 1:2 ratio. The main outcomes were in-hospital and 3-year mortality.

RESULTS: In total, 554 patients with both bronchiectasis and MDR bacterial infection were identified. The types of MDR bacteria that most commonly affected the patients were MDR- Acinetobacter baumannii (38.6%) and methicillin-resistant Staphylococcus aureus (18.4%), Extended-spectrum-beta-lactamases (ESBL)- Klebsiella pneumoniae (17.8%), MDR-Pseudomonas (14.8%), and ESBL-E. coli (7.5%). Compared with the control group, the MDR group exhibited lower body mass index scores, higher rate of chronic bacterial colonization, a higher rate of previous exacerbations, and an increased use of antibiotics. Furthermore, the MDR group exhibited a higher rate of respiratory failure during hospitalization (MDR vs. control, 41.3% vs. 12.4%; p < 0.001). The MDR and control groups exhibited in-hospital mortality rates of 26.7% and 7.6%, respectively (p < 0.001); 3-year respiratory failure rates of 33.5% and 13.5%, respectively (p < 0.001); and 3-year mortality rates of 73.3% and 41.5%, respectively (p < 0.001). After adjustments were made for confounding factors, the infection with MDR and MDR bacteria species were determined to be independent risk factors affecting in-hospital and 3-year mortality.

CONCLUSIONS: MDR bacteria were discovered in patients with more severe bronchiectasis and were independently associated with an increased risk of in-hospital and 3-year mortality. Given our findings, we recommend that clinicians identify patients at risk of MDR bacterial infection and follow the principle of antimicrobial stewardship to prevent the emergence of resistant bacteria among patients with bronchiectasis.