Gas Chromatography-Mass Spectroscopy and antibacterial activity of stem bark of <i>Terminalia glaucescens</i> on some multidrug-resistant gram-negative bacteria

Abstract

Frequent antimicrobial resistance of bacterial pathogens has led to a search for plant origin to synthesize new drugs. Hence, the antibacterial potential of the stem bark part of Terminalia glaucescens plant needs to ascertain. The 162 pure bacteria isolated from the patient’s clinical samples were confirmed using standard procedures to be Escherichia coli (65), Pseudomonas aeruginosa (52), and Klebsiella pneumonia (45). The isolates were tested against seven commonly available antibiotics and the extracts. The identified bark of T. glaucescens was prepared for qualitative analysis using standard methods and also analyzed quantitatively using Gas Chromatography-Mass Spectroscopy (GC-MS). Alkaloid, saponin, flavonoid, steroids, tannin, terpenoid, and phenol were identified. The GC-MS analysis revealed 13 bioactive constituents with Neophytadiene, Squalene, 3, 7, 11, 15-Tetramethyl-2-hexadecen-1-ol and 9-eicosyne as active components. Antibiogram study revealed that most isolates, especially E. coli and P. aeruginosa, were 100% resistant to more than two antibiotics. The antibacterial activity of the stem bark of T. glaucescens was reflected by inhibition zones, ranging from 5.5 mm to 12.5 mm; Escherichia coli had the highest zone of inhibition (12.5 mm). The presence of phytochemicals and bioactive components in this stem bark suggests its effectiveness in treating infections and producing pharmaceutical products.