Multilocus Variable Number of Tandem Repeat Analysis for molecular typing of uropathogenic Escherichia coli

Background: The aim of this study was genotyping of Uropathogenic Escherichia coli (UPEC) based on Variable Number of Tandem Repeats (VNTRs) sequences. Methods: : E. coli strains isolated from urine samples were included in this study. Seven VNTR loci were subjected to Multilocus variable-number tandem repeat analysis (MLVA) based on PCR amplification. Then data was analyzed via online mlvaplus software and the information was displayed in the form of MST analysis. Results: : A total of 100 E. coli strains were isolated and subjected to the study. MLVA was able to differentiate 56 different genotypes. Also, the technique could classify E. coli isolates in 5 clonal complexes. Based on UPGMA dendrograms, E. coli isolates were classified into 4 clusters (clusters A to D). The strains associated with Complex No. 1 appeared to be dominant pathogens of UPEC in Tehran's patients. The present study provides valuable insights into the genetic relationships of E . coli isolates recovered from clinical cases in a major hospital in Iran. Conclusions: : The analysis of MLVA profiles using the MST algorithm showed the usefulness of the MLVA method in the classification of uropathogenic E . coli collected in different periods. We evaluated MLVA in a laboratory equipped with simple molecular equipment. Based on these results, it has been assumed that the E. coli strains were derived from a limited number of clones that have undergo a small genetic change during this period.