Background: One of the most prevalent infectious diseases in the world is urinary tract infections (UTIs). Escherichia coli (E.coli) is the pathogen most often isolated from simple UTIs. E. coli must get beyond the host's defense mechanisms, such as urine flow, uroepithelial cell exfoliation, endogenous antimicrobial agents, and invading neutrophils, in order to establish infection in the urinary tract. Therefore, the bacterium known as uropathogenic E. coli (UPEC) possesses several virulence and fitness characteristics that allow it to withstand and surpass these various defense mechanisms. Furthermore, a large number of putative virulence or fitness variables have considerable redundancy. Fimbriae are required for adhesion to and invasion of the host cells; type 1 pilus is a well-known virulence factor in UPEC and is essential for a urinary tract infection to be successful. Toxins and flagella encourage the spread of germs, yet several iron-acquisition mechanisms enable bacterial survival in the iron-deficient urinary tract environment. The immunological reaction to UPEC is principally facilitated by toll-like receptors that identify flagella, lipopolysaccharide, and additional bacterial surface features. Urosepsis is a type of sepsis which originates from the urogenital tract infections. UPEC is the most common cause of urosepsis. It is responsible for 50% of urosepsis cases. Conclusion: UPEC have the capacity to subvert immune response of the host by means of actively impacting on pro-inflammatory signalling pathways, or by physical masking of immunogenic structures. Urosepsis can be a serious condition, especially in patients with low immunity and those without treatment.