Pseudomonas aeruginosa is frequently isolated from various disease and nosocomial infections. It is clinically important because of its multiple antibiotic resistance and biofilm production. The aims of this study were to determine the production of biofilm and to make antibiotyping and genotyping of P. aeruginosa strains isolated from bronchial aspirate samples of dogs with pneumonia in Turkey and Romania. For this purpose, biofilm properties of 10 Turkish and 10 Romanian isolates were determined by Congo red agar method. The resistance profiles of the isolates were determined by Kirby-Bauer Disk Diffusion Method. The antibiotyping was performed according to the resistance profiles of the isolates. Genotypical similarities were determined by RAPD-PCR. In terms of biofilm production, all of the isolates examined in this study were found to be positive. In consequence of the antibiograms, the resistance rates against enrofloxacin, ceftriaxone, amoxicillin + clavulanic acid, ciprofloxacin, meropenem, colistin, gentamicin and azithromycin were stated as 30%, 70%, 100%, 40%, 30%, 10%, 10%, 100% for Turkish isolates and 30%, 60%, 100%, 30%, 10%, 0%, 10%, 100% for Romanian isolates, respectively. As a result of antibiotyping, similarities of the isolates from Turkey and Romania were determined to be between 86-100%. Phylogenotypical similarities of the isolates from Turkey and Romania were determined to be between 47-96%. It was concluded that antibiotic resistances of isolates were high and resistance against antibiotics used in the treatment could be formed due to biofilm production.
