Typing of the Shiga toxin – Producing Escherichia coli strains isolated from diarrheic children using Multi Locus Sequence Typing (MLST)

Background and Aim: Shiga toxin-producing Escherichia coli (STEC) may also be referred to as Escherichia coli pathotypes, since E. coli serogroups O۲۶ and O۱۵۷ are frequently implicated in outbreaks of diarrhea in children. This study aimed to analyze the clone relationship of Shiga toxin-producing E. coli serogroups O۱۵۷ and O۲۶ isolated from diarrhea in children less than ۶۰ months by Multilocus Sequence Typing (MLST) method. Materials and Methods: A total of ۲۰ Shiga toxins-producing E. coli (STEC strains were selected from two serogroups O۲۶ and O۱۵۷ isolated from diarrheic children, and the PCR products from amplification of seven housekeeping genes were sequenced in them. The nucleotide sequences of each gene in each isolate were analyzed, then queried to the MLST database and, in addition, determination of allele-specific of each gene were determined of sequence types (ST). Results: A total of ۳ clones ST۱۰, ST۱۱ and ST۲۱ were identified from ۲۰ isolates, which identified three gene clusters A, B and C, respectively. Conclusions: Despite of the different ST were found in our isolates studied. There was no a high genetic diversity among the two serogroup O۲۶ and O۱۵۷ isolates, which indicates the clone relationship between E. coli isolates circulating in Tehran.

کلیدواژه ها:

Shiga toxin ، Escherichia coli (STEC) ، Diarrheic children ، Multi-locus Sequence Typing (MLST) ، اشریشیاکلی ، شیگاتوکسین ، اسهال کودکان ، ترادف یابی چندجایگاهی