Endotoxic activity of lipopolysaccharides isolated from emergent potentialcystic fibrosis pathogens

Improved antimicrobial therapies against the classical spectrum of pathogen ic bacteria which colonise the lungs of cystic fibrosis (CF) patients has r esulted in improved life expectancy and quality of life. Bacterial species that are resistant to a broad rang of antibiotics including Stenotrophomona s maltophilia and Alcaligenes xylosoxidans have now emerged as potential ne w pathogens to fill the niche. At present, it is unclear from clinical data whether these microbes are commensal or pathogenic. In this study we have quantified the inflammatory potential of lipopolysaccharide (LPS) from eigh t species of Gram-negative organisms which have been cultured with increasi ng frequency from CF patients. Inflammatory responses induced by LPS from w hole human blood and a human-derived monocyte cell line (THP-1) were assess ed. Enzyme-linked immunosorbent assays were used to detect interleukin-6, i nterleukin-8, and tumour necrosis factor a (TNF). A bioassay was also used to assess TNF activity. With the exception of S. maltophilia, LPS extracted from all of the bacteria tested upregulated, by varying degrees, expressio n of each of the proinflammatory cytokines assayed. This study represents t he first comprehensive report of the endotoxic potential of a new wave of m icrobes which are associated with CF. (C) 2000 Published by Elsevier Scienc e B.V. All rights reserved.