Effect of Lactobacillus spp. cell-free supernatant against planktonic growth and biofilm formation of foodborne Escherichia coli isolates

Comprehensive genomics, probiotic, and antibiofilm potential analysis of Streptococcus thermophilus strains isolated from homemade and commercial dahi

This study investigated the probiotic properties and antibiofilm potential of Streptococcus thermophilus strains obtained from homemade and commercial dahi. The S. thermophilus strain from homemade dahi had greater acid tolerance than the commercial strain, indicating a greater capacity to live in the acidic environments of the stomach. The commercial strain had increased survivability in bile salts and was more hydrophobic than the homemade strain. These findings suggest improved adaptability and increased colonization in the gut. The genomes of both strains included genes associated with probiotic characteristics implying that the two strains may provide unique probiotic advantages. These findings highlight the importance of cell-free supernatants (CFS) of these strains in reducing biofilm formation of pathogenic bacteria. Gas chromatography-mass spectrometry demonstrated that 2, 4-di-tert-butylphenol was a shared metabolite in the CFSs of both strains; however, 2-butanol was found only in the CFS of the homemade dahi strain. In-silico investigations revealed that compounds have drug-like characteristics, suggesting that they could be used for treating biofilm-associated diseases. This study highlights the health advantages of probiotics found in traditional dahi, but it also provides a way to develop natural antibacterial medicines.

Antibacterial Efficacy of Feline-Derived Lactic Acid Bacteria against Enteropathogenic Escherichia coli: A Comprehensive In Vitro Analysis

This study evaluated the antibacterial efficacy of 700 feline-derived lactic acid bacteria (LAB) strains against enteropathogenic Escherichia coli (EPEC), a common cause of diarrhea in cats. Following comprehensive screening, strains ZY25 and ZY35 were identified as the most effective, with inhibition zones of ≥22 mm. These strains demonstrated strong tolerance against stress conditions, such as low pH, bile salts, and gastrointestinal fluids, alongside high hydrophobicity and auto-aggregation abilities. Safety evaluations confirmed the absence of hemolytic activity, virulence factors, and antibiotic resistance genes. The antibacterial activity of these strains is attributed to the production of organic acids, particularly lactic acid and acetic acid. These findings suggest that strains ZY25 and ZY35 have potential as natural and effective probiotic treatments for managing EPEC-induced diarrhea in cats, thus offering an alternative to conventional antibiotics.