(A Peer Review Journal)
e–ISSN: 2408–5162; p–ISSN: 2048–5170


Pages: 39-42
Lucky Evbuomwan1, Ikechukwu Bright Jacob2, Fortune Itoje Ebiala1* and Emeka Patrick Chukwuka

keywords: Antibiotics, antimicrobial, resistance, sensitivity, inhibition, phytochemical


This work was carried out to evaluate the phytochemical and antibacterial activities of Psidium guajava (Guava) leaf extract against clinical bacteria species including Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Escherichia coli, Streptococcus pyogenes. The phytochemicals found in Psidium guajava included flavonoids, saponins, anthraquinones, glycosides, tannins, alkaloids and steroids using ethanol and aqueous as solvent of extraction. The ethanol extract was observed to be effective against the test isolates with zones of inhibition ranging from 9.4 ± 0.03 mm in Klebsiella pneumoniae to 18.0 ± 0.30 mm in Escherichia coli, at concentration 100 mg/ml while reduced activity was observed at lower concentrations. The aqueous extract was found to be less effective against the test isolates compared to the ethanol extract, with zones of inhibition ranging from 7.5 ± 0.03 mm in Klebsiella pneumoniae to 14.0 ± 0.30 mm in Escherichia coli at 100 mg/ml. Minimum inhibitory concentration (MIC) values ranged from 6.25 mg/ml against Escherichia coli to 50 mg/ml against Klebsiella pneumoniae in both extracts. Minimum bactericidal concentrations (MBC) ranged from 25 mg/ml against Escherichia coli and Bacillus subtilis to 100 mg/ml against Klebsiella pneumoniae in the ethanoic extract. MBC for aqueous extract ranged from 25 mg/ml in Escherichia coli to 100 mg/ml in Staphylococcus aureus. Antibiotic sensitivity pattern of the test bacterial isolates revealed varying degree of resistance and the organisms were observed to show multiple drug resistance to the drugs. From this study, Psidium guajava aqueous and ethanolic extracts may be promising alternative or replacement for commonly used antibiotics.


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