[Comparison of three methods for preparation of bacterial ghosts from avian pathogenic Escherichia coli]

Area of Science:

• Microbiology
• Biotechnology
• Vaccinology

Background:

• Bacterial ghosts (BGs) are bacterial cell envelopes lacking cytoplasmic contents, serving as potential vaccine and drug delivery vectors.
• Avian pathogenic Escherichia coli (APEC) strain DE17 was utilized for BG preparation and characterization.

Purpose of the Study:

• To investigate efficient methods for preparing bacterial ghosts from APEC strain DE17.
• To evaluate the efficacy of lysis plasmids and cell-penetrating peptides (CPPs) in BG production and inactivation.
• To assess the biosafety of BG preparation for potential vaccine applications.

Main Methods:

• Preparation of bacterial ghosts from APEC DE17 using three distinct methods.
• Utilization of a lysis plasmid containing the PhiX174 lysis gene E for efficient cell cleavage.
• Application of a cell-penetrating peptide (CPP), MAP, for bacterial inactivation and morphological analysis via Scanning Electron Microscopy (SEM).

Main Results:

• A cleavage efficiency of 99.9% was achieved for DE17 bacterial ghosts using the PhiX174 lysis gene E.
• SEM revealed transmembrane tunnels in DE17 cell envelopes prepared with the lysis plasmid.
• MAP treatment (10 μmol/L) completely inactivated APEC DE17, altering cell envelope structure without visible tunnels, and lysis plasmid expression of MAP did not induce lysis.

Conclusions:

• The PhiX174 lysis gene E is highly effective for producing bacterial ghosts from APEC DE17.
• Cell-penetrating peptide MAP effectively inactivates APEC DE17, though it does not induce lysis via plasmid expression.
• Findings contribute to optimizing bacterial ghost preparation and provide insights into the biosafety of bacterial ghost vaccines.