[Investigation of serum resistance for Pseudomonas aeruginosa and Acinetobacter baumannii strains]

Serum resistance is one of the major virulence factors of Gram negative bacteria. The aim of this study was to investigate the serum resistance of Pseudomonas aeruginosa and Acinetobacter baumannii strains isolated from various clinical samples (19 tracheal aspirates, 14 urine, 7 sputum, 7 wound and one peritoneal fluid specimens). Forty-eight P. aeuginosa and 48 A. baumannii strains were tested for human serum bactericidal effect by using Benge's method. Thirty-five (72.9%), 9 (18.7%), and 4 (8.3%) of P. aeruginosa strains were found to be resistant, intermediate sensitive and sensitive to serum, respectively. These rates were detected as 81.2% (39/48), 14.5% (7/48), and 4.1% (2/48) for A. baumannii strains, respectively. It can be concluded that, high serum resistance rates of P. aeruginosa and A. baumannii isolates might have an important role in the pathogenesis of infections of these bacteria.