[Frequency of isolation and drug resistance of bacterial strains isolated from respiratory material in patients with cystic fibrosis].

During 1985, 251 respiratory samples from 61 patients were examined at the tuscan cystic fibrosis Center (Florence), and isolated strains were tested against various antimicrobial drugs. Pseudomonas aeruginosa and Staphylococcus aureus were the predominant pathogens isolated. Infections caused by St. aureus were the commonest during the first years of life, whereas those caused by Ps. aeruginosa, occasional at early age, became chronic and the main source of infection with growth. Sensitivity testings against antibiotics confirmed that Ps. aeruginosa isolated from cystic fibrosis patients has a high percentage of resistant strains. The most active drugs were ceftazidime and aztreonam. An increased resistance to aminoglycosides was observed.