Evaluation of <i>Escherichia coli</i> aggR Gene Expression in the Presence of Different Concentrations of Creatinine

Abstract

Background: Chronic renal failure is an irreversible disease associated with elevated blood creatinine levels and substantial mortality and morbidity in children worldwide. Enteroaggregative Escherichia coli (EAEC) is a diarrheagenic agent that possesses several virulence factors, including aggR. Objectives: This study aimed to evaluate aggR gene expression in EAEC under different levels of creatinine exposure. Methods: Initially, three biochemically confirmed E. coli isolates obtained from medical laboratories in Borujerd city, western Iran, were molecularly evaluated by 16S ribosomal RNA (16S rRNA) gene amplification. Next, the isolates were assessed for the aggR gene using polymerase chain reaction (PCR). Isolates carrying the aggR gene were cultured in Brain Heart Infusion (BHI) medium supplemented with 1, 3, and 6 mg/dL creatinine (37oC for 24 hours). The expression level of aggR was evaluated in creatinine-exposed isolates using real-time PCR. Results: Among 50 clinical E. coli isolates, three were EAEC, and one of these isolates carried the aggR gene. Real-time PCR showed that aggR gene expression decreased significantly in the presence of varying creatinine concentrations (P < 0.0001). Conclusions: These findings warrant further investigation to elucidate the role of creatinine in modulating bacterial virulence gene expression in the context of renal disorders.