Comparative Study of Biofilm Formation and Virulence Factors of Pseudomonas aeruginosa Isolated from Clinical and Environmental Sources in Kano State

Pseudomonas aeruginosa isolated from clinical and environmental sources may exhibit different virulence and biofilm characteristics, with implications for understanding hospital pathogen emergence in northern Nigerian settings. This study compares biofilm formation ability and virulence factors in Pseudomonas aeruginosa isolates from clinical specimens and hospital environmental sources in Kano State, North West Nigeria. Clinical isolates were obtained from wound swabs, tracheal aspirates, and urine catheters at Aminu Kano Teaching Hospital, while environmental isolates were recovered from sink drains, water taps, and mop water. Biofilm formation was quantified by the crystal violet microtitre plate method. Virulence factor profiling covered protease production, haemolysin production, pyocyanin production, and siderophore activity. Multiplex PCR detected toxA, lasB, algD, and pelB virulence genes. Clinical isolates showed significantly higher biofilm-forming capacity (p = 0.003) and greater frequency of toxA and algD gene possession than environmental isolates. Pyocyanin production was higher in clinical strains. However, 22 percent of environmental isolates demonstrated virulence factor profiles comparable to clinical strains, suggesting environmental reservoirs with pathogenic potential. Antibiotic resistance was broadly distributed across both source groups. The study provides evidence supporting hospital environmental decontamination as a strategy to interrupt pathogenic P. aeruginosa transmission in the Kano tertiary healthcare context. Keywords: Pseudomonas aeruginosa, biofilm, virulence factors, Kano, clinical and environmental isolates