Biological features of biofilm-forming ability of Acinetobacter baumannii strains derived from 121 elderly patients with hospital-acquired pneumonia

This study is to investigate a biological activity of Acinetobacter baumannii isolates from sputum specimens of 121 elderly patients with hospital-acquired pneumonia. The ability of the isolates to form biofilms was quantitatively assessed by crystal violet staining, and adhesive property was examined using Giemsa staining. Biofilm-forming ability by the isolates was employed to test antimicrobial resistance and examine sources and clinical manifestations. The isolates grew as biofilm on abiotic surface at the indicated temperatures after a 48 h of incubation. 27.3 % of the isolates were strongly biofilm-positive in the samples, and 84.8 % displayed high adhesion ability ( P