Biofilm Formation and Detection of Pgaabcd Gene in Clinical Isolates of Extended-spectrum Betalactamase E.coli

Background Biofilm formation is a critical virulence factor in Escherichia coli , especially in multidrug-resistant and extended-spectrum beta-lactamase (ESBL) producing strains. The pgaABCD operon plays a vital role in synthesizing poly-beta-1,6-N-acetyl-D-glucosamine, a key exopolysaccharide in biofilms. This study aimed to detect pgaABCD genes and evaluate biofilm formation in ESBL-producing E. coli from clinical isolates. Methods A cross-sectional study was conducted from August 2023 to March 2024. A total of 384 clinical samples were cultured and E. coli isolates were tested for antimicrobial susceptibility using the Kirby-Bauer method per CLSI 2020 guidelines. ESBL production was screened using the combined disk method. Biofilm production was determined using Congo Red Agar. The presence of pgaABCD genes was assessed using conventional PCR and gel electrophoresis. Results Among 384 clinical samples, 29 (7.55%) E. coli isolates were recovered from urine. Of these, 65.5% were biofilm producers, and 67% exhibited multidrug resistance (MDR). ESBL production was confirmed in 4 isolates. The pgaD gene was the most prevalent (89.6%), followed by pgaB (82.7%), pgaA (68.9%), and pgaC (58.6%). Conclusions The high prevalence of biofilm-forming and MDR E. coli isolates harboring pgaABCD genes underscores the clinical significance of these genes in antibiotic resistance and persistence. Understanding their distribution contributes to inform targeted therapeutic and infection control strategies. Trial Registration Not applicable