ASSESSMENT OF THE SIGNIFICANCE OF VIRULENCE FACTORS OF UROPATHOGENIC ESCHERICHIA-COLI IN EXPERIMENTAL URINARY-TRACT INFECTION IN MICE

Four Escherichia coli strains, isolated from cystitis patients, belong ing to serotype O2:H- and possessing different combinations of uroviru lence factors were examined in an experimental pyelonephritis mouse mo del to assess the relative importance of virulence factors in causatio n of urinary tract infections (UTI). The results suggest not only that the each virulence factor has a role in causation of UTI but also tha t the presence of P fimbriae and production of hemolysin significantly reduced the LD(50) and ID50 of the strains in the mouse model. The re sults also demonstrate that the presence of additional virulence facto rs acts in an additive or synergetic fashion enhancing the cumulative impact of the strain.