Multiresistant 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 preva lence of multiresistant Gram-negative strains in Italy. We found 272 multir esistant strains out of 1560 Gram-negative strains isolated in 1012 Italian cystic fibrosis patients. From our results in Italian cystic fibrosis pati ents we may conclude: (1) the beta-lactam antibiotics are moderately active ; ceftazidime is the most efficacious even if 59.9% of multiresistant strai ns are not sensitive to this drug; (2) the aminoglycosides are poorly effic acious; 93% of multiresistant strains are resistant in vitro to tobramycin; and (3) the quinolones, notwithstanding their relatively recent introducti on into clinical practice, have very poor activity against multiresistant s trains, 89.7% of which are not sensitive.