RT Journal Article SR Electronic(1) A1 GARCíA, APOLINARIA A1 SALGADO, FERNANDO A1 SOLAR, HENRY A1 GONZáLEZ, CARLOS L. A1 ZEMELMAN, RAüL A1 OñTATE, ANGELYR 1999 T1 Some immunological properties of lipopolysaccharide from Acinetobacter baumannii JF Journal of Medical Microbiology, VO 48 IS 5 SP 479 OP 483 DO https://doi.org/10.1099/00222615-48-5-479 PB Microbiology Society, SN 1473-5644, AB Summary 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 α tumour necrosis factor (TNF-α) 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-α. 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., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-48-5-479