Abstract
Mucoid strains of Pseudomonas aeruginosa isolated from the respiratory tract of patients with cystic fibrosis (CF), those obtained from non-CF patients, and those obtained in vitro by the action of phage, were found to be stable in their mucoid colonial form when serially subcultured on deoxycholate-citrate agar. The ability of anionic, cationic and neutral surfactants to stabilise mucus production is described. The possible importance of dipalmitoyl lecithin as a stabilising agent for mucus production in vivo is considered, with particular reference to the role of mucoid P. aeruginosa in CF disease.