Comparative analysis of diarrheagenic and uropathogenic <i>Escherichia coli</i> isolates: antimicrobial resistance, virulence, and genomic profiling

Abstract

AIMS: Escherichia coli is a key pathogen causing gastrointestinal and urinary tract infections. Diarrheagenic E. coli (DEC) and uropathogenic E. coli (UPEC) are distinct major pathotypes linked to specific clinical outcomes. Therefore, this study aimed to compare DEC and UPEC isolates regarding distribution, antimicrobial resistance, serotypes, resistance, and virulence gene profiles. MATERIALS AND METHODS: A total of 400 clinical samples (200 stools and 200 urine) were analyzed using phenotypic and genotypic methods. Antimicrobial resistance, serotyping, and detection of resistance and virulence genes were performed. Phylogenetic and correlation analyses were conducted to explore genetic relationships and interactions. RESULTS: Of 97 E. coli isolates (24.25% prevalence), 56 DEC and 41 UPEC were detected. DEC isolates primarily included serotypes O26, O45, and O55, while UPEC predominantly featured O1 and O25. UPEC showed higher multidrug resistance, while DEC was more virulent. UPEC carried unique markers (ureC, papC), and DEC harbored stx and aggR genes associated with gastrointestinal infections. Phylogenetic analysis showed separate clustering for DEC and UPEC, with limited genetic overlap. Correlation analysis identified strong associations within resistance and virulence genes but a negative correlation between these traits. CONCLUSION: This study compared the phenotypic and genetic features of DEC and UPEC, highlighting their distinct pathogenic traits. Limited genetic overlap suggests potential gene transfer, influencing adaptability, and evolution.