In Vitro Antimicrobial Activity of Modified Lysozyme (Lys 90) and Herbal Extracts Against Multidrug-Resistant Escherichia coli

Abstract

The emergence of Antimicrobial Resistant (AMR) poses a significant challenge to the poultry farming industry. This study investigated the potential of Lysozyme (Lys), modified Lysozyme (Lys 90), an herbal extract, and their combination (herbs + Lys 90) as alternative antimicrobial agents against Multidrug-Resistant Escherichia coli (MDR-E. coli). Lys 90 was prepared by heating Lys at 90 °C for 20 minutes. The herbal extract consisted of garlic (Allium sativum), lempuyang (Zingiber aromaticum), ginger (Zingiber officinale), and turmeric (Curcuma domestica) in a ratio of 4:2:1:1. Antibacterial activities of Lys, Lys 90, herbal extract, and their combination (herbs + Lys 90) against MDR-E. coli were evaluated using agar well diffusion method. Morphological effects of these treatments on MDR-E. coli cells were examined using Scanning electron microscopy (SEM). The results indicated that combination (herbs + Lys 90) produced a significantly larger inhibition zone against MDR-E. coli compared to Lys, Lys 90, and the herbal extract alone. The SEM analysis revealed that MDR-E. coli cells treated with Lys, Lys 90, the herbal extract, and combination (herbs + Lys 90) exhibited notable morphological changes, including cell elongation, pore formation, and structural damage. Combination of (herbs + Lys 90) represents a promising initial strategy for combating MDR-E. coli. However, this approach is limited to in vitro studies. Therefore, further in vivo investigations and comprehensive toxicity assessments are necessary to evaluate the safety and efficacy of this combination before it can be considered for application in the treatment of MDR-E. coli infections in poultry.