In-silico Screening of Endophytic Fungal Metabolites from Stevia rebaudiana as Potential Therapeutics against Multidrug-Resistant Poultry Pathogens

Abstract

Resistance to available antimicrobials constitutes a significant challenge to medicine, with animals identified as critical reservoirs of resistant pathogens. Pseudomonas aeruginosa and Acinetobacter baumannii continue to gain attention and are capable of multidrug resistance including resistance to carbapenems. This study determined the susceptibility profiles of P. aeruginosa and A. baumannii and the potential of selected fungal metabolites from Stevia rebaudiana against selected pathogens from poultry farms in Ogbomoso. Ten poultry faecal samples were collected from five poultry farms for the isolation of P. aeruginosa and A. baumannii using Glutamate Starch Phenol Red and CHROMagar, respectively, following standard methods. Bacteria were identified by their distinct colonial and biochemical features and antibacterial susceptibility testing was performed using the Kirby–Bauer disc diffusion method. The pharmacokinetic profiling of bio-metabolites from endophytic fungi associated with Stevia rebaudiana was determined by molecular techniques. A. baumannii and P. aeruginosa were isolated from all the poultry faecal samples. Gentamycin, ofloxacin and ciprofloxacin were the most effective antimicrobial agents with 53.8% and 46.2% sensitivity, respectively. The presence of phenolic compounds, sterols and fatty acids showed that the plant contains diverse secondary metabolites with potential antimicrobial properties. Most metabolites showed favourable predicted absorption properties with intestinal absorption ranging from 71% to 95% across the metabolites.  P-glycoprotein (P-gp) substrate profiles were positive for benzene acetic acid, cis-9-octadecenoic acid and ergosterol. The total clearance for all metabolites ranged from 0.159 to 2.032 Log ml/min/kg. Conclusively, metabolites from S. rebaudiana demonstrated favourable predicted pharmacokinetic properties as potential drug candidates. Molecular simulation studies are essential to validate these bio-metabolites as potential alternative antimicrobials against these resistant pathogens.