FIG 5.

Suppressor analysis reveals that ica is required for cell aggregation. (A) SRB1243 cells (SA564 ΔcodY soa-1) were grown to exponential phase in TSB and assayed for aggregation. ****, P < 0.0001 (by ANOVA with Dunnett’s postanalysis comparing samples to wild type). (B) SEM of suppressor mutant cells sampled during exponential growth in tryptic soy broth. The image is representative of multiple experiments. (C) Settling assay performed on isogenic strains during exponential growth in TSB. **, P < 0.01; ***, P < 0.001 (by ANOVA with Dunnett’s postanalysis). Here, the ΔcodY and mraY* ΔcodY mutants are significantly different from the wild type. (D) Complementation using the sarA P1 promoter to constitutively express icaB. ***, P < 0.001 (by two-tailed Student t test comparing +icaB [P_sarAP1-icaB⁺] to +vector). (E) CSLM micrographs of ΔcodY soa-1 cells harboring pCN51 or pKM26 (P_sarAP1-icaB⁺) during exponential growth in TSB. All cells were visualized using Syto 40 (blue signal), while eDNA and dead cells were stained by TOTO-1 (green signal). All images are representative of multiple experiments. All panels are viewed at the same magnification.