Characterization of Bifidobacterium asteroides Isolates.

Area of Science:

• Microbiology
• Probiotics
• Food Safety

Background:

• Bifidobacteria are recognized for their probiotic and therapeutic properties.
• Honeybee gut microbiota is a potential source of novel probiotic strains.
• Safety is a critical prerequisite for the human use of probiotic bacteria.

Purpose of the Study:

• To characterize Bifidobacterium asteroides BA15 and BA17 strains isolated from honeybee gut.
• To evaluate the safety of these strains for human consumption.
• To assess their probiotic potential through various functional properties.

Main Methods:

• Phenotypic characterization including antibiotic resistance profiling, hemolytic, DNase, and gelatinase activity assays.
• Genotypic characterization through whole-genome sequencing to identify specific resistance and virulence genes.
• Assessment of functional properties such as antimicrobial activity, auto-aggregation, co-aggregation, and hydrophobicity.

Main Results:

• Both Bifidobacterium asteroides BA15 and BA17 strains met all safety requirements based on phenotypic and genotypic analyses.
• Genome sequencing revealed the absence of genes associated with glycopeptide and tetracycline resistance (e.g., vanA, vanB, tetM).
• No genes encoding for key virulence factors (e.g., asa1, gelE, esp) were detected in either strain.

Conclusions:

• Bifidobacterium asteroides BA15 and BA17 strains demonstrate a strong safety profile for potential human probiotic applications.
• The absence of transferable antibiotic resistance and virulence genes supports their safe use.
• These honeybee-derived strains hold promise as novel probiotics with therapeutic potential.