title: COPD is characterized by increased detection of Haemophilus influenzae, Streptococcus pneumoniae and a deficiency of Bacillus species.
abstract: OBJECTIVE
  Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and inflammation. Airway bacterial colonization is increased in COPD; however, the role of potentially pathogenic and non-pathogenic bacteria in the pathogenesis of disease is unclear. This study characterized the presence of bacteria in a well-characterized cohort of adults with COPD and healthy controls.
  
  
  METHODS
  Adults with COPD (n = 70) and healthy controls (n = 51) underwent clinical assessment and sputum induction. Sputum was dispersed, and total and differential cell counts were performed. Bacteria were cultured, identified and enumerated. Supernatants were assessed for neutrophil elastase (NE) and IL-1β. Common respiratory pathogens were also determined using real-time PCR.
  
  
  RESULTS
  Participants with COPD had a typical neutrophilic inflammatory profile. The total load of bacteria was increased in COPD and was associated with poorer respiratory health status, as measured by the St George's Respiratory Questionnaire (Spearman's r = 0.336, P = 0.013). Significantly lower levels of culturable Bacillus species were identified compared with healthy controls. PCR analyses revealed increased rates of detection of potentially pathogenic bacteria with Haemophilus influenzae detection associated with higher sputum levels of NE and IL-1β, while Streptococcus pneumoniae was more common in male ex-smokers with emphysema and a deficit in diffusion capacity.
  
  
  CONCLUSIONS
  Non-pathogenic and pathogenic bacteria were altered in the sputum of patients with COPD. These observations highlight the potential to identify treatment and management strategies that both target specific bacterial pathogens and restore the microbial balance, which may lead to reductions in inflammation and subsequent improvements in lung health.
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Jodie L
authors.initials: JL
authors.lastname: Simpson
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Baines
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Jay C
authors.initials: JC
authors.lastname: Horvat
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Ama-Tawiah
authors.initials: AT
authors.lastname: Essilfie
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Alexandra C
authors.initials: AC
authors.lastname: Brown
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Melinda
authors.initials: M
authors.lastname: Tooze
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.|Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, John Hunter Hospital, New Lambton Heights, New South Wales, Australia.
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: McDonald
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.|Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, John Hunter Hospital, New Lambton Heights, New South Wales, Australia.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Gibson
authors.affiliation: Centre for Asthma and Respiratory Diseases and Hunter Medical Research Institute, The University of Newcastle, Callaghan, New South Wales, Australia.
authors.forename: Philip M
authors.initials: PM
authors.lastname: Hansbro
mesh_terms: D000328:Adult; D000368:Aged; D001407:Bacillus / Q000302:isolation & purification*; D058491:Bacterial Load; D016022:Case-Control Studies; D005260:Female; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D006801:Humans; D053583:Interleukin-1beta / Q000032:analysis; D007958:Leukocyte Count; D019272:Leukocyte Elastase / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009504:Neutrophils; D029424:Pulmonary Disease, Chronic Obstructive / Q000382:microbiology* / Q000503:physiopathology; D013183:Sputum / Q000737:chemistry / Q000166:cytology / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D053583:Interleukin-1beta; D019272:Leukocyte Elastase
keywords: bacteria; chronic obstructive pulmonary disease; inflammation; pathogen