Experimental Hematogenous Pyelonephritis due to Escherichia coli in Rabbits: The Antibody Response and Its Protective Capacity

The antibody response to the infecting Escherichia coli strain, as well as the protective effect of antibodies to the O, K, and H antigens, was analyzed in rabbits with experimental hematogenous pyelonephritis. The rabbits were infected by intravenous injection of E. coli O6:K13:H1 after ligature of the left ureter for 24 hr. By hyperimmunization of different rabbits with E. coli O6:K2a,2c:H1, E. coli O22:K13:H1, and E. coli O2:K2ab:H1, it was possible to show that antibodies to O6 and K13 antigens, but not H1 antibodies, protected against the hematogenous pyelonephritis. By the indirect hemagglutination technique a marked antibody response to O6 after challenge was shown in all of the rabbits not pre-immunized with an O6-containing strain. Only a moderate antibody response to K13 (in some rabbits no response at all), was noted. The latter might be due to inadequate antigenic stimulation or to induction of tolerance in the rabbits.