Pathomechanism of urinary tract infections caused by uropathogenic E. coli strains

Urinary tract infections (UTIs) are one of the most often and most common bacterial infections affecting even 150 millions of people each year worldwide. The problem of these infections results from chronicity, recurrences and increasing drug resistance of uropathogens causing them. Uropathogenic E. coli strains (UPEC) are the dominant causative agent of UTIs. These strains have many adhesion factors located on the surface of their cells responsible for the initial stage of adherence and colonization of the urinary tract. Among UPEC, the most common virulence factors are monoadhesive pili of type 1 and P and poliadhesins of Dr family, that biogensis is carried out via the conserved secretion pathway of chaperone-usher type (CUP). In addition to urovirulence factors, the UPEC strains developed a number of mechanisms important in pathogenesis of UTIs and enabling them to survive in the urinary tract environment (adhesion, invasion, formation of intracellular aggregates and quiescent bacterial reservoirs, filamentation of bacteria, resistance to antibiotics). Commonly used antibiotic therapy seems to be very effective in the control and treatment of UTIs. However, the increasing multidrug resistance of bacterial strains and the high frequency of recurrences and chronicity of the infections are the basis for the development of alternative therapeutic forms and prevention strategies.