Direct sputum analysis of Pseudomonas aeruginosa macrorestriction fragment genotypes in patients with cystic fibrosis

Med Microbiol Immunol. 1997 Oct;186(2-3):93-9. doi: 10.1007/s004300050050.


The distribution of bacterial populations in the airways of 13 patients with cystic fibrosis who were colonized for 6-23 years with Pseudomonas aeruginosa was investigated by genotyping of bacterial chromosomes directly isolated from 21 sputa. After removal of host material from sputum by hypotonic cell lysis and repetitive washing and centrifugation steps, agarose-embedded bacterial cells were lysed, residual eukaryotic DNA separated by field inversion gel electrophoresis, and the purified bacterial chromosomes subjected to macrorestriction fragment pattern and Southern analyses. Bacterial populations consisted of a single P. aeruginosa clone in 17 sputa, of which more than one clonal variant was apparent in two SpeI fragment fingerprints. Two clones of P. aeruginosa and another species co-existed in four samples. Genomically homogeneous populations of P. aeruginosa are characteristic for chronically colonized lungs in most cases of cystic fibrosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Chronic Disease
  • Cystic Fibrosis / complications
  • Cystic Fibrosis / microbiology*
  • DNA, Bacterial / genetics
  • DNA, Bacterial / isolation & purification
  • Electrophoresis, Gel, Pulsed-Field
  • Female
  • Genotype
  • Humans
  • Male
  • Pseudomonas Infections / complications
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / genetics*
  • Pseudomonas aeruginosa / isolation & purification*
  • Respiratory Tract Infections / complications
  • Respiratory Tract Infections / microbiology
  • Sputum / microbiology*


  • DNA, Bacterial