Abstract Introduction Burkholderia, Achromobacter, and Stenotrophomonas species are associated with worse clinical outcomes in cystic fibrosis (CF),1 though little is known about their prevalence or pathogenicity in non-CF bronchiectasis (pwBE). Herein we describe the prevalence and clinical characteristics of pwBE who isolated each of these three organisms. Methods We conducted a retrospective cross-sectional analysis of baseline data from the US Bronchiectasis and Nontuberculous Mycobacteria (NTM) Research Registry (BRR). Adult bronchiectasis patients with known Achromobacter, Burkholderia cepacia complex (BCC), or Stenotrphomonas maltophilia culture results were included. Patients were stratified according to the presence of at least one positive culture among the gram-negative species. Demographics, clinical characteristics, and first annual follow-up culture results were summarized descriptively for the overall study population and between groups. No inferential analyses or hypothesis testing was performed. Results 5003 pwBE met the inclusion criteria, of which 39 (0.78%) isolated Achromobacter species, 11 isolated Burkholderia (0.22%), and 288 isolated Stenotrophomonas maltophilia (5.8%). Patients with Achromobacter were older, with a median age (interquartile range) of 76 (73.0-79.0) years, compared to the overall bronchiectasis cohort (69.0 years). Those with Burkholderia or Stenotrophomonas were younger, at 69.0 (53.0-75.0) and 71.0 (63.0-77.0) years, respectively. A high proportion of those with Achromobacter were male (31%) versus those with Burkholderia (9%) and Stenotrophomonas (24%), were current or former smokers (46%), were more likely to have had one or more exacerbations in the 2 years prior to enrollment (87%) than the overall BE cohort (57%), and were more likely to have had pulmonary-related hospitalization than those with either Burkholderia or Stenotrophomonas (46% vs. 27% and 19%, respectively). PwBE who isolated Burkholderia were less likely to have co-colonization with Pseudomonas aeruginosa or NTM species (9% each). At first annual follow-up, no patients with baseline Burkholderia isolated them at follow-up, and only 31% with baseline Stenotrophomonas isolated it at follow-up. Conclusion Overall prevalence of Achromobacter, Burkholderia, and Stenotrophomonas species in the BE cohort was low. Patients who isolated Achromobacter species were older, more likely to be current or former smokers, and more likely to experience pulmonary exacerbation and hospitalization. 15 patients who had not previously isolated Achromobacter, and 3 patients who had not previously isolated Burkholderia did so at annual follow-up. Interestingly, no patients with baseline Burkholderia isolates went on to isolate it at annual follow-up, which contradicts earlier studies in pwCF.2 The number of patients isolating Burkholderia in the U.S. BRR is very low, thereby limiting interpretation. This abstract is funded by: None
Swenson et al. (Fri,) studied this question.