Identify and characterize a carbapenem-resistant Salmonella enteritidis phage depolymerase Dpo52

Area of Science:

• Microbiology
• Bacteriology
• Genomics

Background:

• Salmonella enteritidis causes foodborne illness, with rising multidrug-resistant strains, particularly carbapenem-resistant isolates.
• Bacterial biofilm formation is a key factor contributing to antibiotic resistance.
• Limited research exists on phage depolymerases targeting carbapenem-resistant S. enteritidis.

Purpose of the Study:

• To characterize a novel phage, vB_Sen_S3P, and its depolymerase (Dpo52) for potential therapeutic applications against carbapenem-resistant Salmonella enteritidis.
• To evaluate the efficacy of Dpo52 in inhibiting biofilm formation in multidrug-resistant S. enteritidis strains.

Main Methods:

• Isolation and genomic analysis of the phage vB_Sen_S3P from sewage.
• Expression and purification of the phage depolymerase Dpo52.
• Assessment of Dpo52's host specificity, activity, stability, and non-cytotoxicity.
• Evaluation of Dpo52's impact on S. enteritidis biofilm formation.

Main Results:

• Phage vB_Sen_S3P infected 22 out of 30 clinical S. enteritidis isolates, including carbapenem-resistant strains.
• The depolymerase Dpo52 was successfully expressed, purified, and found to be stable across a wide pH and temperature range.
• Dpo52 demonstrated non-cytotoxicity to macrophages and effectively inhibited biofilm formation in S. enteritidis via extracellular polysaccharide degradation.

Conclusions:

• This is the first report of a Salmonella enteritidis phage depolymerase, Dpo52.
• Dpo52 shows significant potential as a therapeutic agent to combat biofilm formation in carbapenem-resistant Salmonella enteritidis infections.