title: Persistence of Staphylococcus aureus L-form during experimental lung infection in rats.
abstract: The course of pulmonary infection in rats infected by intranasal inoculation with a Staphylococcus aureus stable protoplast L-form was studied. Blood and bronchoalveolar samples were taken on days 3, 7, 14 and 30 after challenge and were investigated by microbiological, electron-microscopic, cytochemical and cytometric methods. The electron microscopic data and isolation of L-form cultures from bronchoalveolar samples at all experimental times demonstrated the ability of S. aureus L-form cells to internalize, replicate and persist in the lungs of infected rats to the end of the observation period, in contrast to the S. aureus parental form. It was found that persisting L-form evoked ineffectual phagocytose by alveolar macrophages and low but long-lasting inflammatory reaction in rats. The experimental model of pulmonary infection with S. aureus L-form suggests that the cell-wall-deficient bacterial forms may be involved in the pathogenesis of chronic and latent lung infections.
authors.affiliation: Department of Morphology of Microorganisms, Institute of Microbiology, Bulgarian Academy of Sciences, Sofia, Bulgaria.
authors.forename: Lilia
authors.initials: L
authors.lastname: Michailova
authors.forename: Vesselin
authors.initials: V
authors.lastname: Kussovsky
authors.forename: Tatyana
authors.initials: T
authors.lastname: Radoucheva
authors.forename: Mimi
authors.initials: M
authors.lastname: Jordanova
authors.forename: Nadya
authors.initials: N
authors.lastname: Markova
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology; D005260:Female; D007740:L Forms / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure; D016676:Macrophages, Alveolar / Q000276:immunology / Q000382:microbiology / Q000648:ultrastructure; D008297:Male; D017348:Microscopy, Electron, Scanning Transmission; D046529:Microscopy, Electron, Transmission; D010587:Phagocytosis; D011023:Pneumonia, Staphylococcal / Q000382:microbiology*; D051381:Rats; D017208:Rats, Wistar; D013211:Staphylococcus aureus / Q000472:pathogenicity / Q000502:physiology* / Q000648:ultrastructure