Correlation of Rhs elements with Escherichia coli population structure

Area of Science:

• Microbiology
• Bacterial Genetics
• Evolutionary Biology

Background:

• The Rhs family comprises composite genetic elements in bacteria.
• Understanding their variation is key to deciphering bacterial population structures.

Purpose of the Study:

• To investigate the variation of Rhs elements within the Escherichia coli ECOR reference collection.
• To correlate Rhs element composition and location with the clonal structure of E. coli strains.

Main Methods:

• Comparative analysis of Rhs element presence, location, and sequence across independent E. coli strains.
• Utilizing the ECOR reference collection for strain diversity.

Main Results:

• Rhs element location and content strongly correlate with the clonal structure of E. coli strains.
• Identical segments (core-extension-b1) were found in different clonal groups, suggesting recent shuffling of Rhs elements.
• Two novel Rhs elements, RhsF and RhsG, were identified, expanding the known Rhs subfamily diversity.

Conclusions:

• Rhs element variation is closely linked to E. coli clonal diversification.
• The shuffling of Rhs core extensions represents a recent evolutionary event.
• The discovery of RhsF and RhsG provides new insights into the diversity and evolution of Rhs elements in E. coli.