Fig. 2: Surface organelle formation is impaired when GlpG activity is not present in UPEC strain NU149.
From: Rhomboid protease GlpG regulates type 1 pili quality control and virulence in pathogenic E. coli
a Negatively stained electron micrographs of uropathogenic E. coli strain NU149 wild-type, the CRISPR/Cas9 glpG-S201A mutant, and glpG-S201A mutant transformed with inducible plasmid expressing active GlpG. Bar represents 0.5 µm. b Pili from micrographs were quantified by manual counting using n = 30 of E. coli cells per strain. Significant differences between strains were calculated using one-way ANOVA. c Quantification of glpG transcription using RT-qPCR analysis in commensal (K12) and uropathogenic (NU149 and J96) E. coli strains under different growth conditions. glpG mRNA is reported relative to housekeeping gene rrsB. Data are presented as mean values +/− SEM. Each strain was performed in biological triplicates n = 3 and technical triplicates n = 3. Significant differences were determined using one-way ANOVA. d Hemagglutination assay of NU149 E. coli strains confirms glpG mutant strains do not possess type 1 pili. The absence of type 1 pili on E. coli is confirmed by the binding to erythrocytes, forming a dense button of E. coli-bound erythrocytes at the bottom of the well. As a control, hemagglutination was inhibited by the presence of 2% of D-mannose prior to the addition of bacterial cultures. Assay performed in biological triplicate n = 3.
