Evaluation of antibacterial activity of aqueous and methanolic extracts of the truffle Terfezia claveryi against Pseudomonas aeruginosa

OBJECTIVE: To investigate the antibacterial activities of aqueous and methanolic extracts, as well as, partially purified proteins extracted from Terfezia claveryi aqueous, against Pseudomonas aeruginosa (P. aeruginosa).

METHODS: Five percent of the aqueous and methanolic extracts were added to growth medium of P. aeruginosa. The extract that caused growth inhibition (aqueous) was then partially purified using ammonium sulfate precipitation, gel chromatography and ion exchange chromatography. Antibacterial activities of the obtained fractions were assessed using agar-well diffusion test, and then all the results were compared with reference antibiotics. Excremental procedures were performed at the Department of Nutrition and Food Technology and the animal house of Jordan University of Science and Technology, Jordan during the year 2000.

RESULTS: Five percent aqueous extract inhibited the growth of P. aeruginosa by 40.9%, while methanolic extract was ineffective. Partial purification of the aqueous extract using ammonium sulfate precipitation revealed that antimicrobial activity was within the second pellet (25-45%). This fraction was then subjected to gel permeation chromatography using Sephadex G-25. Peak one, of the 2 peaks obtained, possessed higher antimicrobial activity. Peak one was then subjected to ion exchange chromatography using DEAE Sephadex. Only peak one, of the 3 peaks obtained, showed a slight antimicrobial activity. Relative antimicrobial activities of these fractions were found to be superior to most of reference antibiotics used for comparison.

CONCLUSION: Aqueous extract of the truffle Terfezia claveryi contains a potent antimicrobial agent that is protein in nature and may be used in the treatment of eye infections caused by P. aeruginosa.