Multiresistent non-fermentative Gram-negative bacteria in cystic fibrosis patients:the results of an Italian multicenter study.

We carried out an epidemiological study on 2717 patients seen on a regular basis at Italian Cystic Fibrosis Centers with the aim of defining the prevalence of multiresistant Gram-negative strains in Italy. We found 272 multiresistant strains out of 1560 Gram-negative strains isolated in 1012 Italian cystic fibrosis patients. From our results in Italian cystic fibrosis patients we may conclude: (1) the beta-lactam antibiotics are moderately active; ceftazidime is the most efficacious even if 59.9% of multiresistant strains are not sensitive to this drug; (2) the aminoglycosides are poorly efficacious; 93% of multiresistant strains are resistant in vitro to tobramycin; and (3) the quinolones, notwithstanding their relatively recent introduction into clinical practice, have very poor activity against multiresistant strains, 89.7% of which are not sensitive.