Phytochemical Profiling (GCMS) Analysis and Molecular Characterization of Clinically Isolated Escherichia Coli and Staphylococcus Aureus

Abstract

Objective: To evaluate the phytochemical composition of Guiera senegalensis leaf extracts using GC–MS and to molecularly characterize clinical isolates of Escherichia coli and Staphylococcus aureus.
Methods: Leaf extracts were prepared using aqueous and ethanol solvents. Phytochemical constituents were qualitatively and quantitatively assessed, and bioactive compounds were identified using Gas Chromatography–Mass Spectrometry (GC–MS). Clinical bacterial isolates were confirmed by polymerase chain reaction (PCR) amplification, and amplicons were analyzed by gel electrophoresis.
Results: Phytochemical screening revealed flavonoids, alkaloids, phenols, saponins, and tannins in both extracts. Ethanol extracts showed higher yields of alkaloids, phenols, saponins, and tannins compared to aqueous extracts. GC–MS analysis identified several bioactive compounds, including propylcyclohexane (16.56%), methyl n-octadecanoate (39.90%), phytol (a diterpene), esters, and 2-phenylcyclobutyl benzene. Squalene (54.35%) was the predominant compound in the F2 aqueous fraction. Many of these constituents possess documented antimicrobial and antioxidant activities. Molecular characterization confirmed the identities of E. coli and S. aureus, with gel electrophoresis showing distinct DNA bands at approximately 200 base pairs, consistent with positive controls.
Conclusion: Guiera senegalensis leaf extracts contain diverse bioactive compounds with potential antibacterial properties. Molecular confirmation of the test organisms supports the validity of the findings, highlighting the plant as a promising source of novel antimicrobial agents.