Growth and survival of <i>E</i>. <i>faecalis</i> in human urine.

(A) Growth of OG1RF and derivatives in human urine. Overnight cultures were diluted 1:1000 into pooled urine supplemented with 20 mg ml-1 BSA and incubated for 24 hours at 37°C. (B) Human urine was supplemented with 1 mM FeSO4 or 1 mM MnSO4 and growth/survival of wild-type and ΔefaΔmntH1ΔmntH2 strains recorded after 48 hours incubation. Control corresponds to urine without metal supplementation. Aliquots at selected time points were serially diluted and plated on BHI + Mn plates for CFU enumeration. The graphs show the average and standard deviations of three independent experiments. Mutant strains were compared against wild-type OG1RF using one-way ANOVA followed by Sidak’s multiple comparison test. Comparison of the effect of Fe or Mn supplementation on the same strain (#) versus untreated, or between parent and mutant strain (*) under the same conditions, were assessed via two-way ANOVA with Tukey’s post-test. (** and ##p ≤ 0.01, **** and ####p ≤ 0.0001).