title: A comparative study of induction of pneumonia in mice with planktonic and biofilm cells of Klebsiella pneumoniae.
abstract: In the present study, the course of acute pneumonia in normal BALB/c mice infected by intranasal inoculation of planktonic and preformed biofilm cells (3 days old) of Klebsiella pneumoniae B5055 was studied and compared. With both cell forms the peak of infection was observed on the third post infection day, as assessed on the basis of lung bacterial load and corresponding pathology. There was an intense neutrophil infiltration in bronchoalveolar lavage fluid. Tissue damage was assessed on the basis of increased amounts of nitrite, malondialdehyde and lactate dehydrogenase in lung homogenates. The phagocytic potential of alveolar macrophages was lower in biofilm cell-induced infection than in that induced by planktonic cells. Biofilm cell induced infection generated significantly greater production of tumor necrosis factor-α and interleukin-1β on the third and fifth days of infection, respectively. Production of interleukin-10 was, however, variable. There was no significant difference in the ability of planktonic and biofilm cell forms of K. pneumoniae to induce acute pneumonia in mice in terms of bacterial counts and histopathological changes. However, biofilm cell-induced infection showed delayed clearance as compared to infection induced with the planktonic form.
authors.affiliation: Department of Microbiology, Panjab University Department of Pathology, Government Medical College, Chandigarh, India. sonica.sharma@sify.com
authors.forename: Sonica
authors.initials: S
authors.lastname: Sharma
authors.forename: Harsh
authors.initials: H
authors.lastname: Mohan
authors.forename: Saroj
authors.initials: S
authors.lastname: Sharma
authors.forename: Sanjay
authors.initials: S
authors.lastname: Chhibber
mesh_terms: D000818:Animals; D058491:Bacterial Load; D018441:Biofilms / Q000254:growth & development*; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000276:immunology; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D007710:Klebsiella Infections / Q000382:microbiology / Q000473:pathology; D007711:Klebsiella pneumoniae / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity*; D008168:Lung / Q000382:microbiology / Q000473:pathology; D016676:Macrophages, Alveolar / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020556:Neutrophil Infiltration; D009569:Nitric Oxide; D010933:Plankton / Q000472:pathogenicity*; D018410:Pneumonia, Bacterial / Q000382:microbiology / Q000473:pathology*; D014409:Tumor Necrosis Factor-alpha
chemical_list: D016207:Cytokines; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide