Evaluation of genes encoding iron absorption systems in Enteroaggregative Escherichia coli (EAEC) isolates isolated from diarrhea specimens

Most Escherichia coli are not pathogenic. But some strains of E. Coli become pathogenic by acquiring and synthesizing diverse virulence genes. Iron, as an essential nutrient, has a proven role in the pathogenicity of E. coli. One of the most common strategies of microorganisms in the presence of free iron is the production of siderophores. Siderophores act as extracellular agents for the absorption of iron from minerals or organic compounds in the absence of iron. The Purpose of this study was to identify and evaluate the genes encoding iron absorption systems in Enteroaggregative Escherichia coli isolates isolated from diarrhea specimens.

In this study, three panels were designed. Panel 1: iroN, iutA, fecA, Panel 2: fyuA, sitA, irp2 and Panel 3: iucD. In panels 1 and 2, Triplex-PCR method and panel 3, single-PCR method were used and 44 EAEC isolates isolated from diarrhea samples were screened by these three panels.

The results showed that a total of 44 EAEC isolates had respectively the highest frequency of fecA 44(100%), fyuA 43(97.73%), irp2 43(97.73%), iutA 42(95.45%), iucD 34(77.27%), sitA 29(65.91%) and iroN 4(9.09%). and 7 gene profiles encoding different iron absorption systems were identified.

The results showed that EAEC isolates have the ability to produce synthesize a variety of siderophores and use the variety of profiles of different iron absorption systems to obtain the required iron.