High prevalence of Candida dubliniensis in lower respiratory tract secretions from cystic fibrosis patients may be related to increased adherence properties

Abstract

We identified Candida spp isolated from lower respiratory tract secretions obtained from cystic fibrosis (CF) patients, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), with the aim of determining the most prevalent causative agent. We also sought to determine their adhesive properties in order to understand their biology related to CF. Twenty-five clinical samples were collected from a cohort of 20 CF patients. Twenty-six isolates of Candida spp were isolated and identified by MALDI-TOF MS method. Adherence assays were performed using the Fluxion BioFlux 200, a flow apparatus that allows for the visualization of adhering cells. MALDI-TOF MS analysis revealed C. dubliniensis to be the most prevalent species (n=18, 69%), followed by C. albicans (n=4), C. tropicalis (n=3), and C. glabrata (n=1). C. dubliniensis showed the strongest adherence under constant flow when compared to the other species of Candida. In the majority of cases, C. dubliniensis was isolated in combination with Pseudomonas aeruginosa and Staphylococcus aureus. C. dubliniensis appears to be able to survive in the CF lung and coexist with bacteria. The data presented here show that the presence of C. dubliniensis in the lower airways of CF patients may be related to increased adherence properties.