Multiplex PCR-based Molecular Characterization of Fecal-Derived Multidrug-Resistant Escherichia coli Isolates

Antimicrobial resistance (AMR) in Escherichia coli presents a serious public health threat, particularly when resistant strains spread through contaminated food and water. This study characterized fecal-derived multidrug-resistant (MDR) E. coli isolates using multiplex polymerase chain reaction (PCR) to detect extended-spectrum β-lactamase (ESBL) gene variants (blaTEM, blaOXA, blaSHV, and blaCTX-M), sulfonamide resistance genes (sul1, sul2, and sul3), and integron-associated integrase genes (int1, int2, and int3). We analyzed 62 uspA-positive E. coli isolates. Results showed that 82.25% of isolates carried none of the targeted bla genes. The blaCTX-M and blaOXA genes were present in 8.06% and 9.67% of isolates, respectively. Co-occurrence of bla and sul genes appeared in 12.91% of isolates. Co-occurrence of bla and int genes occurred in 12.90%. Only 6.45% of isolates carried at least one gene from all three categories, indicating potential MDR genotypes. These findings highlight the importance of molecular surveillance in tracking resistance genes outside clinical settings. They support the need for integrated One Health strategies to combat AMR.