title: Role of haemophilus pleuropneumoniae lipopolysaccharide endotoxin in the pathogenesis of porcine Haemophilus pleuropneumonia.
abstract: Intact Haemophilus pleuropneumoniae cells (strain Shope 1, serotype 1), highly purified lipopolysaccharide (LPS) obtained from this strain of H pleuropneumoniae, as well as from Escherichia coli O111:B4, filter-sterilized H pleuropneumoniae cell-free culture supernatant fluid, and heat-inactivated supernatant fluid were given intranasally to CF1 mice and intratracheally to pigs. Pulmonary lesions induced by H pleuropneumoniae in mice were similar to those induced by H pleuropneumoniae in pigs. Histologically, lungs of mice and pigs killed 1 or 2 days after inoculation with 200 micrograms of highly purified H pleuropneumoniae LPS had lesions similar to one another and were similar to those in mice and pigs given intact H pleuropneumoniae, except that little or no necrosis or hemorrhage was observed. In mice killed 1 or 2 days after inoculation of 200 micrograms of E coli O111:B4 LPS, pulmonary lesions were similar to those in mice given H pleuropneumoniae LPS. Pulmonary lesions in mice given cell-free culture supernatant fluid obtained from a midlog-phase growth culture of H pleuropneumoniae cultivated in a chemically defined medium were severe and consisted of neutrophil infiltration and extensive necrosis. In mice, the heat-inactivated supernatant fluid produced mild lesions that consisted of foci of neutrophil aggregation and no necrosis. Extensive necrosis observed in lesions caused by cell-free culture supernatant fluid could be attributed to the action of a heat-labile component, perhaps by the extracellular heat-labile hemolysin produced by H pleuropneumoniae cultivated in chemically defined medium. A LPS endotoxin and a heat-labile factor may be involved in the pulmonary lesion development in the acute phase of porcine Haemophilus pleuropneumonia.
mesh_terms: D000818:Animals; D004731:Endotoxins / Q000633:toxicity*; D006190:Haemophilus; D006192:Haemophilus Infections / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D008070:Lipopolysaccharides / Q000633:toxicity*; D008168:Lung / Q000473:pathology; D008297:Male; D051379:Mice; D011001:Pleuropneumonia / Q000209:etiology / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000209:etiology / Q000382:microbiology* / Q000473:pathology
chemical_list: D004731:Endotoxins; D008070:Lipopolysaccharides