Flagellate and non-flagellate Proteus mirabilis in the development of experimental urinary tract infection.
Three isolates of Proteus mirabilis from symptomatic human urinary tract infections (UTI) were tested for their ability to cause renal infection in mice. All three strains were fimbriated as tested by hemagglutination. One of the strains, Pr 988, did not possess flagella, whereas the other two did and were capable of swarming on solid rich media. We compared the capacity of these strains to infect mice in both the ascending and hematogenous mouse UTI models. Infection was assessed by counting viable bacteria in kidney and bladder homogenates in ascending UTI or by the presence of abscesses in the hematogenously inoculated mice. All three strains were able to infect mice in both UTI models. These results suggest that flagella are not absolutely necessary for virulence in these experimental models.