Escherichia coli is one of the most common causes of infections in human, especially in the urinary tract and in the bloodstream. Enzymes belonging to the beta-lactamases group can break beta-lactam - a structure in common antibiotics. E. coli with multidrug resistant traits have a high association with sequence type 131 and its dangerous subclone H30-Rx. In this project, 161 isolates from urinary tract infections and sepsis in Sweden were analyzed with the Freebayes variant calling method. In combination with clinical tests, bioinformatics tools were tested to classify the H30-Rx subclone. Two methods were built up for specific analysis of subclone H30-Rx. There were 35 samples belonging to subclone H30-Rx detected by the accurate method and 87 ST131 samples. The bioinformatics method identified 45 samples belonging to subclone H30-Rx, with anMCC value of 0.85 which can potentially be developed to a rapid diagnosis tool. The result of SNP analysis suggested that the re-infected rate of E. coli can be extremely high due to the rising prevalence of ST131 in the Swedish population, although the percentage of subclone H30-Rx might decrease. This study highlights the dangers of ST131 E. coli and its subclone H30-Rx as a warning to the ineffective treatment against multidrug resistant pathogens and the potential healthcare burden in the near future.