Detection of Pseudomonas aeruginosa in sputum from cystic fibrosis patients by the polymerase chain reaction.

A DNA amplification procedure using heat stable Taq polymerase and the polymerase chain reaction is described for the detection of Pseudomonas aeruginosa in specimens from cystic fibrosis patients. A set of primers was selected on the basis of the nucleotide sequence of the algD gene encoding GDP mannose dehydrogenase, a major enzyme in the biosynthesis of alginate by P. aeruginosa. Using this set of primers in conjunction with the polymerase chain reaction, P. aeruginosa could be specifically detected, with a sensitivity approximating 10 bacteria, in sputum harbouring large numbers of other respiratory pathogens, including Staphylococcus aureus and Haemophilus influenzae. These results suggest that amplification of specific sequences within the algD gene by the polymerase chain reaction may provide a highly sensitive and specific tool for the detection of P. aeruginosa in the early stages of pulmonary colonization.