Biocidal potentials and chemical composition of leaf extract of Chrysophyllum albidum (G. Don) against selected enterobacterial species obtained from clinical samples

Abstract

The biocidal potentials of the fractions partitioned from the Chrysophyllum albidum leaf extract were assessed against selected enterobacterial species obtained from clinical samples. Sensitivity test, minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and time-kill assay were used to evaluate antibacterial properties. The chemical constituents present in the fractions were also investigated using Fourier Transform Infrared Spectroscopy (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS) analyses. The fractions at 10 mg/mL displayed zones of inhibition that were between (10±0.82) mm and (24±1.63) mm. The MICs ranged from 0.63 mg/mL to 5 mg/mL while the MBCs ranged from 1.25 mg/mL to 10 mg/mL. Escherichia coli and Klebsiella pneumoniae were completely eliminated by the n-butanol fraction after 120 minutes of contact time at 1 x MIC while the killing rates for these bacteria in the aqueous and ethyl acetate fractions were 95.5% and 89.4% respectively. Numerous functional groups, including alcohol, phenol, alkanes, alkenes, aliphatic ether, amide, amines, aromatics, carboxylic acids and sulfoxides were found in the sample after FT-IR analysis. One of the main constituents found in the GC-MS analysis of the plant extract was 9-octadecenoic acid. This investigation showed that leaf extract exhibited significant biocidal potentials against selected enterobacterial species isolated from clinical samples. Thus, further research is required to isolate the pure bioactive constituents from the fractions.