Bacteria that infect the lungs of people with cystic fibrosis evolve into different forms in various parts of the lungs.

Pradeep Singh at the University of Washington in Seattle and his team dissected the infected lungs of ten people with the disease who were having lung transplants, and analysed the genomes of Pseudomonas aeruginosa bacteria sampled from different areas of the lung. Comparing areas that were mildly and severely diseased, the team found distinct lineages of the bacterium with variations in virulence, antibiotic resistance and other factors. They conclude that this diversity arose because bacterial cells became isolated in lung regions where they then evolved separately.

This regional diversification could enhance resistance to drugs and human defences, the authors say.

Cell Host Microbe http://doi.org/6zw (2015)