title: [Serum sensitivity of Pseudomonas aeruginosa isolated from sputum as a virulence factor in the lower respiratory tract].
abstract: To elucidate the clinical significance of serum-sensitivity of respiratory pathogenic Pseudomonas aeruginosa (P. aeruginosa) strains, we examined serum-sensitivity of P. aeruginosa isolated from 16 patients with lower respiratory tract infections and clinical backgrounds of these patients. We also evaluated the virulence of four serum-resistant and four serum-sensitive P. aeruginosa strains in murine pneumonia model induced by intratracheal challenge, and the silver-stained profiles of purified lipopolysaccharide (LPS) from these strains. Serum-sensitive strains were isolated only from patients with chronic bronchitis, bronchiectasis, and diffuse panbronchiolitis colonized with P. aeruginosa, and rarely caused pneumonias, while serum-resistant strains caused pneumonias in some cases. Intratracheal challenge of mice with 5 x 10(7) cfu per mouse of a serum resistant strain caused fatal hemorrhagic pneumonia with bacteremia. In contrast, the same dose of a serum-sensitive strain provided non-fatal pneumonia without bacteremia. LD50 of serum-sensitive strains in a murine model of P. aeruginosa pneumonia were at least 2-10 times higher than those of serum-resistant strain. The LPS profiles of two serum-resistant strains and one serum-sensitive strain showed ladder-like patterns. The similar analysis demonstrated that one serum-sensitive strain was lack of ladder-like patterns. These data support that serum-sensitive P. aeruginosa strains are less virulent than serum-resistant P. aeruginosa strains in the lower respiratory tract, and serum sensitivity of P. aeruginosa strains is determined by the structure of the O-side chain of LPS; either lack of the O-side chain or the presence of sparse O-side chain.
authors.affiliation: Department of Internal Medicine, Nagasaki University, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Sonoda
authors.forename: K
authors.initials: K
authors.lastname: Oishi
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Hideaki
authors.forename: S
authors.initials: S
authors.lastname: Kobayashi
authors.forename: T
authors.initials: T
authors.lastname: Nagatake
authors.forename: K
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000494:pharmacology; D051379:Mice; D011014:Pneumonia / Q000382:microbiology*; D011552:Pseudomonas Infections; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity*; D012703:Serotyping; D013183:Sputum / Q000382:microbiology*; D014774:Virulence
chemical_list: D007106:Immune Sera