Pseudomonas aeruginosa is an ubiquitous bacterium and opportunistic pathogen that plays an important role in nosocomial infections. The presence of virulence factors and the biofilm-forming ability of this species contributes to a high risk of treatment complications. In this study, we examined the biofilm-forming ability and the prevalence of five virulence factor genes (pslA, pelA, ppyR, fliC, and nan1) in 271 P. aeruginosa isolates (212 from dogs and 59 from cats). Biofilm-forming ability was detected in 90.6% of isolates in dogs and 86.4% of isolates in cats. In P. aeruginosa isolates from both species, the most prevalent virulence factor gene was ppyR (97.2% in dogs and 98.3% in cats), followed by pslA (60.8% and 57.6%), fliC (60.4% and 69.5%), nan1 (45.3% and 44.1%), and pelA (40.1% and 33.9%, respectively). In dogs, a significantly higher proportion of biofilm-forming P. aeruginosa strains possessed the fliC gene compared to non-biofilm-forming strains (p = 0.015). In cats, a significantly lower proportion of biofilm-forming strains had the nan1 gene compared to non-biofilm-forming strains (p = 0.017). In conclusion, the presence of fliC gene and the absence of nan1 gene could be indicators of biofilm-forming ability of P. aeruginosa.
Keywords: Pseudomonas aeruginosa; biofilm; cats; dogs; virulence genes.