British Medical Bulletin 2002;61: 81–96 The British Council 2002 Persistent and aggressive bacteria in the lungs of cystic fibrosis children

There have been enormous improvements in life expectancy of patients with cystic fibrosis, especially with improved nutrition and better understanding of the basic cellular defects. However, infection in particular with Pseudomonas aeruginosa and Burkholderia cepacia, has the greatest effect in decreasing life expectancy. Although infections can be prevented by rigorous infection control procedures, early aggressive antimicrobial chemotherapy and established infection managed by antibiotics, they are not completely effective. A greater understanding of how the bacteria evade the host defences and produce infection is needed. Cystic fibrosis (CF) is an autosomal recessive disorder resulting from mutations in a gene on the long arm of chromosome 71. The gene product is the cystic fibrosis transmembrane conductance regulator (CFTR) which regulates and facilitates transport of electrolytes across epithelial cell and other membranes. The mutations, (over 1000 described so far), can be by frameshift, deletion or by base substitution leading to amino acid sub