Microbial colonization and lung function in adolescents with cystic fibrosis

Abstract

With intensified antibiotic therapy and longer survival, patients with cystic fibrosis (CF) are colonized with a more complex pattern of bacteria and fungi. However, the clinical relevance of these emerging pathogens for lung function remains poorly defined. The aim of this study was to assess the association of bacterial and fungal colonization patterns with lung function in adolescent patients with CF. Microbial colonization patterns and lung function parameters were assessed in 770 adolescent European (German/Austrian) CF patients in a retrospective study (median follow-up time: 10years). Colonization with Pseudomonas aeruginosa and MRSA were most strongly associated with loss of lung function, while mainly colonization with Haemophilus influenzae was associated with preserved lung function. Aspergillus fumigatus was the only species that was associated with an increased risk for infection with P. aeruginosa. Microbial interaction analysis revealed three distinct microbial clusters within the longitudinal course of CF lung disease. Collectively, this study identified potentially protective and harmful microbial colonization patterns in adolescent CF patients. Further studies in different patient cohorts are required to evaluate these microbial patterns and to assess their clinical relevance.

Co-colonisation with Aspergillus fumigatus and Pseudomonas aeruginosa is associated with poorer health in cystic fibrosis patients: an Irish registry analysis

“…This is the first time this has been reported. In a recent longitudinal study the sputum microbiology and clinical outcomes of 770 adolescents with CF were recorded and AF was the only species that was associated with an increased risk for infection with PA [28]. This highlights the importance of monitoring the co-colonisation status of CF patients.…”

The myriad challenges of respiratory fungal infection in cystic fibrosis

“…Once fungi are isolated from the lung, the next question that follows is whether these microbes are contaminants, transiently recovered, colonizers, or pathogens. The clinical outcomes related to presence of bacteria in the CF lung may be either protective or deleterious, and this understanding has influenced thinking about the isolation of fungi . Definitions for Aspergillus colonization and infection have been proposed, though there remain no standardized definitions.…”

“…C albicans , the most common species isolated, is generally thought of as non‐pathogenic. This being said, when identified as a colonizer of the CF airway C albicans is associated with increased rates of decline in FEV 1 in some studies; while an association with preserved lung function was found in another study …”

Viral–bacterial interactions in the respiratory tract

“…CF patients are frequently colonized with P. aeruginosa (Hector et al, 2016) and, like COPD patients, are prone to develop exacerbations upon viral infection. Chattoraj et al (2011a) showed decreased production of type I and III IFNs in CF cells exposed to P. aeruginosa and HRV compared with cells exposed to HRV alone.…”