Alterations of c‐di‐GMP turnover proteins modulate semi‐constitutive rdar biofilm formation in commensal and uropathogenic Escherichia coli

Abstract

Agar plate‐based biofilm of enterobacteria like Escherichia coli is characterized by expression of the extracellular matrix components amyloid curli and cellulose exopolysaccharide, which can be visually enhanced upon addition of the dye Congo Red, resulting in a red, dry, and rough (rdar) colony morphology. Expression of the rdar morphotype depends on the transcriptional regulator CsgD and occurs predominantly at ambient temperature in model strains. In contrast, commensal and pathogenic isolates frequently express the csgD‐dependent rdar morphotype semi‐constitutively, also at human host body temperature. To unravel the molecular basis of temperature‐independent rdar morphotype expression, biofilm components and c‐di‐GMP turnover proteins of seven commensal and uropathogenic E. coli isolates were analyzed. A diversity within the c‐di‐GMP signaling network was uncovered which suggests alteration of activity of the trigger phosphodiesterase YciR to contribute to (up)regulation of csgD expression and consequently semi‐constitutive rdar morphotype development.

DncV Synthesizes Cyclic GMP-AMP and Regulates Biofilm Formation and Motility in Escherichia coli ECOR31

“…The swimming motility of ECOR31, though, was not altered upon either overexpression or deletion of csgD compared to the ECOR31 wild-type (Fig. S2A), suggesting swimming motility of ECOR31 to be csgD independent under the assay conditions used in this work (37).…”

A Cyclic di-GMP Network Is Present in Gram-Positive Streptococcus and Gram-Negative Proteus Species

“…Although we could demonstrate convergent evolution of GGDEF domains with the same N-terminal sensing domain within a panel of enterobacterial species, 40 uncoupling of domain homology from the identity of the N-terminal sensory domain and downstream EAL domain occurs readily in natural isolates. 41 , 42 …”

A recently isolated human commensal Escherichia coli ST10 clone member mediates enhanced thermotolerance and tetrathionate respiration on a P1 phage‐derived IncY plasmid

“…In this work, we initially characterized a commensal representative of the ST10 clonal complex closely related to E. coli K-12. This strain produces a rdar biofilm morphotype at 28°C ( Figure S2; (Cimdins et al, 2017b)) and harbors an IncY plasmid with the previously identified TLPQC/LHR locus that mediates tolerance toward temporal exposure to lethal temperature and additional cargo genes involved in detoxification.…”

“…Unlike E. coli K-12, Fec10 displays a full red, dry, and rough (rdar) morphotype, a distinct biofilm colony phenotype characterized by the production of the exopolysaccharide cellulose and amyloid curli fimbriae as extracellular matrix components at ambient temperature ( Figure S2; Cimdins et al, 2017b). Fec10 is a member of the ST10 strain complex, which opens up the opportunity to document adaptation of a member of the abundant phylogroup A/ST10 E. coli subgroup to post-industrial human beings.…”

“…Other sequence types are more restricted (Manges et al, 2019). Genome sequencing revealed that intestinal and extraintestinal E. coli pathogens can be closely related to innocuous commensal E. coli strains (Cimdins et al, 2017b). Indeed, enterotoxigenic E. coli can readily arise from commensal strains by the acquisition of few genetic elements including the transfer of characteristic virulence plasmids (von Mentzer et al, 2014), indicating that plasmids can readily alter the characteristics of strains.…”