In silico evaluation of phytochemicals present in Bambusa polymorpha and Citrus limon extracts against Salmonella enteric Typhimurium combined with in vitro antimicrobial and acidic stress responsive studies

Abstract

Salmonella enteric serovar Typhimurium is one of the causative agents for non-typhoidal salmonellosis which is highly associated with the consumption animal products such as eggs, pork, and poultry. Phytochemicals present in plant extracts were reported to improve food safety by inhibiting the growth of foodborne pathogens. Herein, the antimicrobial activities of Citrus limon and Bambusa polymorpha extracts were evaluated for their effectiveness in reducing the log counts of strains of S. Typhimurium inoculated in ground pork. The incorporation of undiluted extracts has resulted in 3.95 and 1.88 log reduction of S. Typhimurium, respectively with 2 h of exposure. Phytochemicals in the extracts that interfere with the activity of outer membrane (OmpA) and efflux pump regulatory proteins (MdfA, RamA) were also identified and interactions were anticipated using molecular docking and molecular dynamics simulation (MDS) studies. This study has revealed that the major phytochemicals present in the extracts were viz. phenol-2-ethyl, paracresol, 2, 3-dimethoxybenzoic acid, cyclobarbital, 3-methylsalicylhydrazide, and 3-methoxy-5-methylphenol. In order to evaluate the drug likeness and toxicity, phytochemicals were screened for their physiochemical and absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties. ADMET studies has revealed that the screened phytochemicals with high docking scores had potent anti-bacterial abilities and could be used in drug design studies to develop natural plant products to preferentially target the outer membrane and efflux pump regulatory proteins of S. Typhimurium, which are critically important for the survival of S. Typhimurium under stress condition.