Fig. 1

Transurethral cochallenge of mice with the ExPEC strains with or with the prc mutation. (a, c, and e) Cochallenges of mice with ExPEC prc mutants and their otherwise wild-type strains. Equal numbers of the prc mutants of the indicated ExPEC strains and their otherwise wild-type strains (the lacZ mutants) were transurethrally inoculated into mice. At 48 h post-inoculation (hpi), bacterial colonization levels of the bladder and kidney were determined. (b, d, and f) Cochallenges of mice with the indicated ExPEC prc mutants and their corresponding complemented strains. lacZ and prc double deletion mutants (∆lacZ∆prc) harboring the prc-encoding plasmid pPrc (Table 1) served as the complemented strains. Equal numbers of the prc mutants harboring the empty vector pCL1920 and the corresponding complemented strains were transurethrally coinoculated into mice. The bacterial counts of each strain in the bladders and kidneys were determined at 48 hpi. The bacterial counts of the mutants and the otherwise wild-type or complemented strains in the same organs were differentiated and enumerated by spreading the homogenized infected tissue onto LB agar plates with IPTG and X-gal. Horizontal bars indicate the median level of the bacterial counts. The dotted line represents the limit of detection