title: Some immunological properties of lipopolysaccharide from Acinetobacter baumannii.
abstract: Acinetobacter baumannii, mainly biotype 9, is an important nosocomial opportunist pathogen in Chile and other countries. The biological basis of its virulence and prevalence is still unknown. As lipopolysaccharide (LPS) is often associated with virulence, some biological properties of purified LPS from seven nosocomial isolates, comprising four isolates of A. baumannii biotype 9, two isolates of biotype 8 and one isolate of biotype 1, were investigated. LPS was extracted and purified from each isolate by the hot phenol-water method, and its ability to elicit a mitogenic response and to induce the synthesis of a tumour necrosis factor (TNF-alpha) in mouse spleen cells was determined. Activity was evaluated in vivo by determining the splenic index in comparison with LPS from Salmonella Typhimurium. All seven LPS samples were mitogenic on the basis of cellular proliferation experiments and six induced synthesis of TNF-alpha. Similar results were obtained in in-vivo experiments in which LPS induced spleen cell growth, as shown by determination of the splenic index. These results suggest that the LPS of A. baumannii might contribute to the pathogenic properties of this species.
authors.forename: Apolinaria
authors.initials: A
authors.lastname: GARCíA
authors.forename: Fernando
authors.initials: F
authors.lastname: Salgado
authors.forename: Henry
authors.initials: H
authors.lastname: Solar
authors.forename: Carlos L
authors.initials: CL
authors.lastname: GONZáLEZ
authors.forename: RAüL
authors.initials: R
authors.lastname: Zemelman
authors.forename: Angel
authors.initials: A
authors.lastname: OñTATE
mesh_terms: D000150:Acinetobacter / Q000276:immunology*; D000151:Acinetobacter Infections / Q000382:microbiology; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002478:Cells, Cultured; D003428:Cross Infection / Q000382:microbiology; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013154:Spleen / Q000166:cytology / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha