Lambda Red-mediated Recombineering in the Attaching and Effacing Pathogen Escherichia albertii

Area of Science:

• Microbiology
• Bacterial Pathogenesis
• Genetic Engineering

Background:

• Site-specific mutations are crucial for understanding bacterial pathogen virulence.
• Recombineering, a genetic engineering technique, facilitates DNA manipulation in bacteria.
• Escherichia albertii is an emerging pathogen with cryptic virulence, necessitating genetic study.

Purpose of the Study:

• To develop and validate a modified lambda red recombineering protocol for mutagenizing Escherichia albertii.
• To enable targeted genetic manipulation in E. albertii for virulence factor characterization.

Main Methods:

• Modified lambda red recombineering protocol.
• Electroporation of DNA with homology arms into hyperrecombinogenic bacteria.
• Site-specific deletion and replacement of virulence-associated genetic loci (ler, grlRA, hfq) with drug resistance cassettes.
• FLP-dependent site-specific recombination for marker eviction.

Main Results:

• Successfully deleted and replaced three virulence-associated genetic loci in E. albertii.
• Generated marked and unmarked mutants using a drug resistance cassette and subsequent FRT site-specific recombination.
• Demonstrated the efficacy of the modified recombineering protocol in E. albertii.

Conclusions:

• The developed protocol enables the construction of genome-wide mutations in E. albertii.
• This advancement will facilitate the study of E. albertii's molecular mechanisms of pathogenicity.
• The findings will aid in developing strategies to combat E. albertii outbreaks.