Environmental Pseudomonas aeruginosa in groundwater: association between Multidrug Resistance, Biofilm Formation and Surface Physicochemical Properties

Pseudomonas aeruginosa is a Gram-negative pathogen widely isolated from various environments, including soil, water, and clinical settings. The capacity to persist, form biofilm and resist to antibiotics makes this bacterium a significant public health concern. The aim of this study was to determine the prevalence of P. aeruginosa isolated from well groundwater samples collected from diverse sites, and to evaluate the antimicrobial susceptibility profiles, Biofilm formation capacity, and the surface physicochemical properties of the isolates. A total of 80 samples were analyzed and the antibiotic susceptibility was determined using EUCAST standardized disk diffusion method. Biofilm formation and surface physicochemical characterization were evaluated. Our study revealed a 17.5% (14/80) prevalence of P. aeruginosa in well water samples, with resistance to some commonly used antibiotics; 35.7% of the isolates were classified as Multidrug-resistant (MDR). The studied strains showed a strong capability to form biofilms exceeding 7 Log CFU/cm² on galvanized steel. A significant correlation was observed between biofilm formation, surface physicochemical properties, and MDR. This study highlights the importance of monitoring groundwater quality and application of effective strategies to reduce health risks associated with P. aeruginosa contamination.