Prevalence of <i>pslA</i> and <i>pslB</i> Biofilm-Related Genes in <i>Pseudomonas aeruginosa</i> Isolates from ICU Patients: A Cross-Sectional PCR-Based Study

Background and Aim: Biofilm formation is a key factor in persistence and antibiotic resistance of Pseudomonas (P.) aeruginosa, especially in intensive care units (ICU).This study aimed to explore how common the pslA and pslB genes are in multidrug-resistant (MDR) strains of P. aeruginosa isolated from ICU patients in Tehran and how these genes relate to biofilm development. Materials and Methods:For this cross-sectional study, 112 P. aeruginosa isolates were collected from patients admitted to the ICUs of 1000-bed tertiary care of Milad Hospital, Tehran, Iran.The isolates were identified using standard microbiological techniques.To assess biofilm formation, crystal violet staining was conducted using 96-well microtiter plate.DNA was extracted using a commercial kit, and polymerase chain reaction (PCR) was carried out to detect the pslA/B genes.Results: Of 112 samples, 92 (82.1%) isolates were biofilm producers, among them the vast majority of biofilm-producing strains were tested positive for both pslA (91, 98.9%) and pslB (92, 100%) genes.One pslA-negative isolate from a wound specimen retained weak biofilm-forming capacity.These genes showed a strong association with biofilm development (P<0.05). Conclusion:The high prevalence of pslA/B genes in biofilm-forming MDR isolates suggests their significant role in enhancing biofilm formation and antibiotic resistance.This highlights the need to understand biofilm-related genes in managing ICU infections, though methodological limitations warrant further validation.