Fig 6.

Competitive infection studies of zinc uptake mutants in mouse kidneys. Mice were infected (see Materials and Methods) with equal mixtures of either strains KM-D and KM-DznuC (A) or strains KM-D and KM-DznuC with pNT-znuACB (B). Experimental groups were sacrificed at day 1 and day 4 postinfection. Data are the competitive indices from at least two independent experiments, and the geometric means are noted with a bar. Results were calculated using the following equation: competitive index = (mutant_output/wild type_output)/(mutant_input/wild type_input). Open circles represent mice from which no znuC mutants were cultured, in which cases the limit of detection was used to calculate the competitive index. The significance level was determined by a Mann-Whitney test. The asterisk denotes a P value of 0.01 when comparing the day 1 and day 4 data for infections of KM-D and KM-DznuC.