PHYTOCHEMICAL SCREENING AND ANTIMICROBIAL ACTIVITY OF Khaya senegalensis, Afzelia africana and Erythrophleum ivorense BARK EXTRACTS AGAINST SOME CLINICAL PATHOGENS

Abstract

The study investigates the bio-active composition and bio-activity of bark extracts of Khaya senegalensis, A. africana and E. ivorense on clinical micro-organisms to determine their inhibitory efficacy against pathogenic agents. Phytochemical were extracted from fresh barks of Khaya senegalensis, A. africana and Erythrophylum ivorense species using distilled water, methanol and ethanol as solvents. The antimicrobial activity of the extracts against Klebsiella pneumoniae, Pseudomonas aerigunosa ATCC 27853, Methicillin- resistant Staphylococcusa aureus ATCC 4330, Escherichia coli ATCC 25922, Carbapenem-resistant Pseudomonas Species, Escherichia coli (Carbapenem-resistant strain), Escherichia coli (Non carbapenem-resistant strain)were investigated. The effects of standard antimicrobial agents against these selected pathogenic micro-organisms were also investigated. Results of the phytochemical screening showed that saponins, tannins, basalms, glycosides, steriods, terpenoids and flavonoids were the active compounds present in the bark of the K. senegalensis, A. africana and E. ivorense. The antimicrobial susceptibility test showed that bark extracts of Khaya senegalensis, A. africana and E. ivorensehad varying effects on the growth of the clinical isolates. The aqueous, ethanolic and methanolic extracts of K. senegalensis had the highest zone of inhibition on Pseudomonas 27853, Klebsiella pneumonia, and Escherichia coli (Carbapenem-resistant strain). While A. africana and E. ivorense bark aqueous, methanol and ethanol crude extracts were able to inhibit the growth of Klebsiella pneumonia, Pseudomonas aeruginosa ATCC 27853 and FT3 faecal. The minimum inhibitory concentration of the bark extracts ranges from 25-400mg/ml. There was no minimum bactericidal concentration observed from the extracts. Results of the effect of standard antimicrobial agents against pathogenic micro-organisms indicated multidrug resistance by the test organisms with only Ceftriaxone (CRO) 30μg and Cefepime (FEP) 30 μg eliciting inhibitory activity against Carbapenem-resistant pseudomonas species, Pseudomonas aerigunosa ATCC 27853, and Echerichia coli (non- carbapenem strain) respectively. The result of this study, therefore suggest the possibility of using K. senegalensis, A. africana and E. ivorense extracts as antimicrobial agents, which can be a great asset to drug development for purpose of health care delivery in Nigeria.