The Journal of Medical Microbiology, Vol 15, Issue 3 303-316, Copyright © 1982 by Society for General Microbiology
Virulence of Escherichia coli in ascending urinary-tract infection in mice
T. Iwahi, Y. Abe and K. Tsuchiya
The virulence of Escherichia coli strains in ascending urinary-tract
infection was studied in mice drinking a 5% glucose solution; factors
determining the virulence were examined. Of 33 strains, 8 (group I)
infected the bladder and kidney, 10 (group II) infected only the bladder,
while the remaining 15 strains (group III) did not cause infection. The
adherence of group-I and group-II strains to bladder epithelial cells in
vitro was inhibited by D-mannose. In group III, 13 strains barely adhered
to the epithelial cells, while two strains showed an adherence unaffected
by D-mannose. Most strains in groups I and II agglutinated erythrocytes of
guinea-pig, chicken, and horse, and cells of Candida albicans in a
mannose-sensitive manner. All strains in groups I and II had fimbriae.
Virulence for the urinary tract was not directly related with O-serotype,
intraperitoneal virulence, ability to grow in mouse urine, ability to
ferment dulcitol, production of haemolysin, susceptibility to serum
bactericidal activity, or susceptibility to antibiotics. These results
suggest that the adherence of the E. coli to mouse-bladder epithelial cells
in a mannose-sensitive manner plays an important role in the development of
urinary-tract infection in mice and that the adherence is probably mediated
by type-1 or closely related fimbriae.
