Dr. rer. nat.
Nina Cramer studied biochemistry at the University of Hannover. She joined the group as a PhD student in 2005 to study clonal evolution of Pseudomonas aeruginosa in patients with cystic fibrosis. After finishing her PhD in 2009 she continued with this topic and to gain insight into the adaptation of P. aeruginosa to the CF-lung habitat. She is investigating the genome evolution of P. aeruginosa in contrasting patient cohorts with a very mild or very severe course of their infection. Exopolysaccharide biosynthesis, antimicrobial resistance and global regulators of lifestyle and metabolism were found to be common functional categories whose genes were hit by mutations in all P. aeruginosa clones, irrespective of the severity of infection in the cystic fibrosis host. Microevolution, however, is not uniform in the patients' lungs. For example, the P. aeruginosa clone inhabiting the most severely affected lungs generated progeny with stop mutations or drastic amino acid changes in key genes of lifestyle, whereas the P. aeruginosa clone that has persisted in a patient with normal lung function had diverged into co-existing clades which, accumulated benign, probably modifying amino acid substitutions, but no stop mutations.