Animal-Based Natural Products as Novel Antibacterial Candidates

Abstract

This research study confirms the antibacterial activity of animal-derived compounds against Staphylococcus aureus and Escherichia coli. The tested compounds demonstrated varying degrees of inhibition, with antimicrobial peptides (AMPs), lactoferrin, and ovotransferrin showing the most significant antibacterial effects. AMPs exhibited the highest zone of inhibition, measuring 19 mm against S. aureus and 22 mm against E. coli, followed by lactoferrin (18 mm and 20 mm, respectively) and ovotransferrin (16 mm and 18 mm, respectively). Other compounds, including histatins, lysozyme, and fatty acids, demonstrated moderate antibacterial activity, with inhibition zones ranging between 12 mm and 16 mm. The positive control, ciprofloxacin, exhibited the highest inhibition zones of 38 mm and 36 mm for S. aureus and E. coli, respectively, while the negative control (DMSO or sterile water) showed no inhibition. The minimum inhibitory concentration (MIC) results further supported these findings, with AMPs having the lowest MIC values (8 µg/mL for S. aureus and 4 µg/mL for E. coli), indicating high antibacterial potency at low concentrations. Lactoferrin and ovotransferrin also demonstrated strong antibacterial effects, with MIC values of 16 µg/mL and 32 µg/mL against S. aureus, and 8 µg/mL and 16 µg/mL against E. coli, respectively. Histatins, lysozyme, and fatty acids required higher concentrations to inhibit bacterial growth, with MIC values ranging between 64 µg/mL and 128 µg/mL. Ciprofloxacin showed the lowest MIC values (0.5 µg/mL for S. aureus and 0.25 µg/mL for E. coli), confirming its high efficacy.