Genome-wide transposon mutagenesis of Proteus mirabilis: Essential genes, fitness factors for catheter-associated urinary tract infection, and the impact of polymicrobial infection on fitness requirements
Fig 9
In vitro co-challenge of P. mirabilis mutants in human urine.
Filter-sterilized pooled human urine from healthy donors was inoculated with a 1:1 mixture of wild-type P. mirabilis and the following mutants that exhibited significant fitness defects in vivo: (A and B) lon, (C and D) argR, (E and F) hslU, (G and H) arnA, (I and J) PMI1518, and (K and L) glnA. Cultures were incubated at 37°C for 5 hours, and sampled hourly for determination of CFUs (A, C, E, G, I, and K). Error bars represent mean and error for three independent replicates. No differences in growth between mutants and wild-type were detected by two-way ANOVA with post-hoc test for significance. A competitive index was calculated for each mutant at each hourly timepoint using the ratio of mutant to wild-type at the time of inoculation (B, D, F, H, J, and L). None of the mutants exhibited a significant fitness defect or advantage during growth in urine by the Wilxocon signed rank test.