Structural Elucidation of a Novel B. cenocepacia ET-12 Lipooligosaccharide Isolated from a Cystic Fibrosis Patient after Lung Transplantation

In this work, we carried out the elucidation of a novel lipooligosaccharide (LOS) from a clinical strain of the most virulent strain of the Burkholderia cepacia complex, which was of B. cenocepacia ET-12 epidemic strain lineage. The strain was isolated from a cystic fibrosis patient who had successfully undergone lung transplantation. This molecule presents some specific chemical differences when compared to the LOS reported so far from other B. cenocepacia ET-12 clones. The new endotoxin was also tested as a cytokine enhancer on human myelomonocytic U937 cells. Lipopolysaccharides are the main virulence factors of Gram-negative bacteria, and since they are exposed to the extracellular space, they are deeply involved in bacterial adaptation to the host environment. The characterisation of structural motifs present in these molecules is essential to the comprehension of the persistence/survival mechanisms and inflammatory potential of these bacteria.