Antibacterial Effect of Phytochemial Extracts from Ziziphus-spina christi against Some Pathogenic Bacteria

Abstract

THE ANTIBACTERIAL potential of Ziziphus- spina christi as methanol and ethanol extracts, of bark, fruit, roots, seeds and leaves, were evaluated against seven pathogenic bacterial strains using agar well diffusion technique: The used strains were Pseudomonas aeruginosa (ATCC 278223), Enterobacter cloacae (ATCC 13047), Enterobacter aerogenes (ATCC 13084), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13888), Enterococcus faecalis (ATCC 29212) and Methicillin-resistant Staphylococcus aureus (MRSA, ATCC 43300). The antibiotic erythromycin was used as positive control. The presence of phytochemical compounds in the extracts was determined qualitatively, the functional bioactive groups were characterized by FTIR and the presence of bioactive elements was characterized by XRF. Antibacterial activity against the used bacterial strains was assessed by determining the minimal inhibitory and bactericidal concentrations (MIC and MBC) assays. All the used Gram negative and positive bacteria were sensitive to various plant extracts. Bark extract was the most active against all strains except for Enterobacter aerogenes. Ethanol bark extract showed great activity against Enterococcus faecalis with 16.2 mm clearing zone and MIC, MBC of 15 and 20 mg ml-1, respectively. Methanol bark extract was also effective against Klebsiella pneumoniae with a clearing zone of 16.2 mm and 20 mg ml-1 for both MIC, MBC. Leaves extracts showed high antibacterial activity against all strains except Escherichia coli. Ethanol fruit extract also exhibited high activity against Pseudomonas aeruginosa with 20 mm clearing zone and 2.5, 10 mg ml-1 for both MIC and MBC. Finally, ethanol roots showed the largest clearing zone against Enterococcus faecalis (21mm) with 10 and 15 mg ml-1 for MIC and MBC, respectively.