Figure 5: Regulation of vacJ and yrbE expression in H. influenzae.
From: A novel mechanism for the biogenesis of outer membrane vesicles in Gram-negative bacteria
(a) OMV preparations derived from equivalent OD490 units of cultured Rd KW20 or Rd Δfur grown in BHI–NAD–hemin supplemented without (−dip) or with (+ dip) 2,2′-dipyridyl were analysed for total protein (Bradford) and lipooligosaccharide (Purpald). Mean values with s.e.m. are shown (n=6 biological replicates). (b) Distributions of OMV sizes produced by the strains in different culture conditions were determined by nanoparticle tracking analysis. Mean values with s.d. of mean and mode OMV diameter sizes within respective OMV preparations are shown (n=6 biological replicates). (c) Relative expressions of vacJ and yrbE in Rd KW20 or Rd Δfur grown in BHI–NAD–hemin supplemented without (−dip) or with (+ dip) 2,2′-dipyridyl as well as in Rd KW20 after colonization of the mouse nasopharynx for 4 h (in vivo) were determined by qRT-PCR. (d) Relative expressions of vacJ and yrbE in NTHi 2019-R and NTHi 1479-R grown in BHI–NAD–hemin were determined by qRT-PCR. (c,d) Horizontal bars highlight the mean of each data set (n=6 biological replicates). Dotted lines indicate a relative gene expression of 1. (a,c,d) Significant differences between the data sets are marked by asterisks (P<0.05; one-way ANOVA followed by Sidak’s multiple comparison post test (a,c) or unpaired t-test (d)).
