Achromobacter xylosoxidans characteristics important for lung colonization of cystic fibrosis (CF) patients

Achromobacter xylosoxidans characteristics important for lung colonization of cystic fibrosis (CF) patients M. Trancassini1, N. Citerà1, V. Tuccio1, A. Magni1, V. Iebba, R.V. De Biase2, S. Schippa1 1La Sapienza University, Public Health and Infectious Diseases, Rome, Italy, 2La Sapienza University, Pediatrics, Rome, Italy Objectives: Achromobacter xylosoxidans is an emerging pathogen increasingly isolated from respiratory samples of CF patients, often associated to antibiotic resistance. The present study was aimed to investigate virulent traits of 57 A.xylosoxidans strains isolated from CF patients and correlated the results with patients forced expiratory volume in 1s (FEV1%). Methods: 57 A.xylosoxidans strains were isolated from sputum samples of CF patients attending at the Regional Centre of Cystic Fibrosis of the Umberto I° Hospital of Rome. We carried out a genomic characterization by randomly amplified polymorphic DNA (RAPD) and evaluated A.xylosoxidans biofilm production on abiotic surfaces and antibiotic resistance. Resistance determinants were studied by Polimerase Chain Reaction (PCR) in highly resistant strains. Conclusion: Our results demonstrate the ability of A. xylosoxidans to transfer its extended-spectrum β-lactamase-encoding plasmid. 7 A.xylosoxidans strains had the specific band related to metal β-lattamase, and 3/7 of the them showed to possess specific band of the integron1.All isolates showed to be biofilm producer and were divided in three classes. RAPD profiles resulted to be related to CF pathology status (estimated by FEV 1% values).The ability to form biofilms and the multidrug resistance showed by A. xylosoxidans are certainly important factors influencing its virulence degree and seems to be bacterial features important for the colonization of CF patients with chronic infections and with more severe clinical conditions.