Full Structural Characterisation of the Lipooligosaccharide of a Burkholderia pyrrocinia Clinical Isolate

This paper deals with the full structural elucidation of the lipooligosaccharide from the Gram-negative bacterium Burkholderia pyrrocinia. B. pyrrocinia is one of the nine species included in the Burkholderia cepacia complex (BCC), a group of important opportunistic pathogens in patients with cystic fibrosis and chronic granulomatous disease. B. pyrrocinia strain BTS7, isolated from a patient with cystic fibrosis, was found to exclusively produce a lipooligosaccharide (LOS). This component of the external membrane plays a key role in the virulence of BCC bacteria and is required for resistance to antimicrobial compounds and for bacterial survival. Here we present, for the first time, a detailed study of the structure of the lipooligosaccharide (LOS) elucidated by means of compositional analysis, MALDI and ESI mass spectrometry and 2D NMR spectroscopy. The LOS of B. pyrrocinia was degraded by complete deacylation, dephosphorylation and reduction. The major oligosaccharide representing the carbohydrate backbone was isolated by size-exclusion chromatography and identified. The structural determination of molecules (such as the LOS of B. pyrrocinia) involved in the activation of the pro-inflammatory processes is the first step in the adoption of new therapeutic strategies against lung infections.