Dynamic response by commensal E. coli two-component system Cpx contributes to C. elegans development

Area of Science:

• Microbiology
• Developmental Biology
• Host-Microbe Interactions

Background:

• The Caenorhabditis elegans-Escherichia coli model system allows for single-gene analysis of host-microbe interactions.
• Deletion of E. coli cpxR, a regulator of the envelope stress response, was found to delay C. elegans development.

Purpose of the Study:

• To investigate the mechanisms by which E. coli cpxR influences C. elegans development.
• To explore the role of bacterial metabolism and environmental factors in host-microbe interactions.

Main Methods:

• Screening of E. coli mutants for effects on C. elegans development.
• Analysis of host mitochondrial unfolded protein response pathway activation.
• Culturing E. coli in different media (LB vs. M9) to assess metabolic influence.
• Investigating the effect of N-acetylcysteine on C. elegans phenotypes.

Main Results:

• E. coli ΔcpxR induced C. elegans developmental delay and activated the mitochondrial unfolded protein response via reactive oxygen species.
• Culturing E. coli ΔcpxR in LB medium, but not M9, caused developmental delay, with L-histidine metabolism being a key factor.
• The dynamic response of the E. coli Cpx system, rather than its activation, impacts C. elegans development.
• N-acetylcysteine treatment shifted the C. elegans phenotype from developmental delay to survival resistance, indicating improved host stress tolerance.

Conclusions:

• Environmental factors modulate the E. coli Cpx response in C. elegans.
• These findings offer insights into the variable Cpx-mediated virulence observed in gram-negative bacteria across different environments.