title: Reduced bacterial colony count of anaerobic bacteria is associated with a worsening in lung clearance index and inflammation in cystic fibrosis.
abstract: Anaerobic bacteria have been identified in abundance in the airways of cystic fibrosis (CF) subjects. The impact their presence and abundance has on lung function and inflammation is unclear. The aim of this study was to investigate the relationship between the colony count of aerobic and anaerobic bacteria, lung clearance index (LCI), spirometry and C-Reactive Protein (CRP) in patients with CF. Sputum and blood were collected from CF patients at a single cross-sectional visit when clinically stable. Community composition and bacterial colony counts were analysed using extended aerobic and anaerobic culture. Patients completed spirometry and a multiple breath washout (MBW) test to obtain LCI. An inverse correlation between colony count of aerobic bacteria (n = 41, r = -0.35; p = 0.02), anaerobic bacteria (n = 41, r = -0.44, p = 0.004) and LCI was observed. There was an inverse correlation between colony count of anaerobic bacteria and CRP (n = 25, r = -0.44, p = 0.03) only. The results of this study demonstrate that a lower colony count of aerobic and anaerobic bacteria correlated with a worse LCI. A lower colony count of anaerobic bacteria also correlated with higher CRP levels. These results indicate that lower abundance of aerobic and anaerobic bacteria may reflect microbiota disruption and disease progression in the CF lung.
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Katherine
authors.initials: K
authors.lastname: O'Neill
authors.affiliation: Centre for Health and Rehabilitation Technologies (CHART), University of Ulster, Belfast, United Kingdom.
authors.forename: Judy M
authors.initials: JM
authors.lastname: Bradley
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Elinor
authors.initials: E
authors.lastname: Johnston
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Stephanie
authors.initials: S
authors.lastname: McGrath
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Leanne
authors.initials: L
authors.lastname: McIlreavey
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Stephen
authors.initials: S
authors.lastname: Rowan
authors.affiliation: Belfast Health and Social Care Trust, Belfast, United Kingdom.
authors.forename: Alastair
authors.initials: A
authors.lastname: Reid
authors.affiliation: Centre for Health and Rehabilitation Technologies (CHART), University of Ulster, Belfast, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Bradbury
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Gisli
authors.initials: G
authors.lastname: Einarsson
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; Centre for Infection and Immunity, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: J Stuart
authors.initials: JS
authors.lastname: Elborn
authors.affiliation: CF and Airways Microbiology Research Group, Queen's University Belfast, Belfast, United Kingdom; School of Pharmacy, Queen's University Belfast, Belfast, United Kingdom.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Tunney
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D001420:Bacteria, Aerobic / Q000187:drug effects; D001421:Bacteria, Anaerobic / Q000166:cytology* / Q000187:drug effects; D058491:Bacterial Load; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D002648:Child; D003550:Cystic Fibrosis / Q000150:complications* / Q000382:microbiology*; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D007249:Inflammation / Q000150:complications* / Q000473:pathology*; D008168:Lung / Q000187:drug effects / Q000382:microbiology* / Q000473:pathology; D008297:Male; D064307:Microbiota / Q000187:drug effects; D008875:Middle Aged; D013183:Sputum / Q000187:drug effects / Q000382:microbiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D002097:C-Reactive Protein