Incidence of Acinetobacter baumannii and other pathogens isolated from Intensive Care Unit of the Hospital San Carlo, Genoa - Voltri

Acinetobacter baumannii is an emerging pathogen of great impact especially in nosocomial settings due to its complex epidemiology that makes its control very difficult. In this study the strains isolated from the Intensive Care Unite were analysed. Materials and methods. All the patients admitted into intensive care of San Carlo Hospital,Voltri, Genoa, Italy (ASL 3) in the period from May to December 2009 were considered.A total of 63 patients were studied including 31 women and 32 men, with an average of 73 years old.The study considered the following biological samples (N): bronchial aspirate and sputum (84), urine (55), blood (28), and other materials (36).The positive samples were processed for strain identification and evaluations of its antibiotic susceptibility pattern by standard VITEK2 system, following the Clinical and Laboratory Standard Institute Guidelines. Results and Conclusions. From samples taken into account, the prevalent percentage of bacterial species collected was registered by Gram negative (46.3%), followed by Gram positive (36.4%), and fungi (17.3%). Considering Gram negative isolates A. baumannii and Escherichia coli resulted among the prevalent pathogens (23.4 and 24.5% respectively). This microorganism was collected especially from bronchial aspirate (13) followed by urines (4), blood cultures (2) and other materials (3). On the basis of the analysis of the antibiotic susceptibility tests, colistin was active on the totality (100%) of A. baumannii, followed by tigecycline (96.77%).Amikacin resulted also active against a large proportion of these isolates (93.3%). Present findings confirm the great multidrug resistance phenotype of A. baumanii against the main classes of antimicrobial agents and its dangerous diffusion in the Intensive Care Units. For these reasons a continuous surveillance of the evolution of this pathogen toward antibiotic resistance is requested. In this contest it will be important an evaluation of antibiotic susceptibility following the guidelines suggested by EUCAST (European Committee on Antimicrobial Susceptibility Testing).