title: Relative contribution of Prevotella intermedia and Pseudomonas aeruginosa to lung pathology in airways of patients with cystic fibrosis.
abstract: BACKGROUND
  Patients with cystic fibrosis (CF) with Pseudomonas aeruginosa lung infections produce endobronchial mucus plugs allowing growth of obligate anaerobes including Prevotella spp. Whether obligate anaerobes contribute to the pathophysiology of CF lung disease is unknown.
  
  
  METHODS
  The virulence of Prevotella intermedia and Ps aeruginosa was investigated in vitro and in mice, antibodies against P intermedia in CF sera were assessed and a culture-independent detection method for P intermedia/P nigrescens in CF sputum was tested.
  
  
  RESULTS
  P intermedia reached cell numbers of >10(5)->10(7)&emsp14;colony-forming units (CFU)/ml sputum. The majority of patients with CF (16/17; 94.1%) produced antibodies against two immunoreactive antigens of P intermedia. Culture supernatant fluids, collected from 10(9) P intermedia cells, were more cytotoxic to respiratory epithelial cells in vitro and inflammatory in mouse lungs than respective fluids from anaerobically grown Ps aeruginosa, while fluids from aerobically grown Ps aeruginosa had the highest cytotoxicity and inflammation. Both pathological effects were largely reduced when culture supernatant fluids from 10(7) cells of either species were used. P intermedia cells (∼10(6)CFU/lung) did not induce mortality in the agar beads lung infection mouse model, while Ps aeruginosa cells caused death in 30% of mice due to rapid multiplication. A P intermedia/P nigrescens-specific PNA probe was significantly more sensitive than culture-dependent diagnostic assays to detect these strict anaerobes.
  
  
  CONCLUSIONS
  Ps aeruginosa and P intermedia become significantly virulent in vitro and in vivo when cell numbers exceed 10(8) CFU/lung.
authors.affiliation: Institute of Medical Microbiology and Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Ulrich
authors.forename: Isabelle
authors.initials: I
authors.lastname: Beer
authors.forename: Peter
authors.initials: P
authors.lastname: Braitmaier
authors.forename: Michaela
authors.initials: M
authors.lastname: Dierkes
authors.forename: Florian
authors.initials: F
authors.lastname: Kummer
authors.forename: Bernhard
authors.initials: B
authors.lastname: Krismer
authors.forename: Ulrike
authors.initials: U
authors.lastname: Schumacher
authors.forename: Ute
authors.initials: U
authors.lastname: Gräpler-Mainka
authors.forename: Joachim
authors.initials: J
authors.lastname: Riethmüller
authors.forename: Peter Ø
authors.initials: PØ
authors.lastname: Jensen
authors.forename: Thomas
authors.initials: T
authors.lastname: Bjarnsholt
authors.forename: Niels
authors.initials: N
authors.lastname: Høiby
authors.forename: Gabriel
authors.initials: G
authors.lastname: Bellon
authors.forename: Gerd
authors.initials: G
authors.lastname: Döring
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016866:Bacteroidaceae Infections / Q000150:complications*; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D002478:Cells, Cultured; D015169:Colony Count, Microbial; D003550:Cystic Fibrosis / Q000150:complications*; D006801:Humans; D008168:Lung / Q000382:microbiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009894:Opportunistic Infections / Q000150:complications; D018713:Prevotella intermedia / Q000254:growth & development / Q000276:immunology / Q000302:isolation & purification / Q000472:pathogenicity*; D011552:Pseudomonas Infections / Q000150:complications*; D011550:Pseudomonas aeruginosa / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity*; D012141:Respiratory Tract Infections / Q000150:complications; D013183:Sputum / Q000382:microbiology; D014774:Virulence
chemical_list: D000907:Antibodies, Bacterial