Following both sides of a bacterial infection

What changes as Pseudomonas aeruginosa builds a biofilm on the airway epithelium? With collaborators at Vall d’Hebron, we tracked gene expression in both bacteria and host cells, comparing healthy and cystic fibrosis epithelial models with isolates from acute and chronic infections.

Chronic-infection isolates increased expression of type I, III and VI secretion systems, whereas acute-infection isolates relied more on ABC transporters. The host response also depended on the epithelial background, with prominent cytokine and keratinisation responses in cystic fibrosis models during acute infection.

The study shows why both the bacterial strain and host context matter when interpreting infection. Published in Biofilm.