The inhibitory effect of Streptomyces chromofuscus on -lactamase of Pseudomonas aeruginosa ATCC-10145

摘要

Seventy un-repeated?Streptomyces?isolates were isolated from different agricultural regions in Riyadh city. Amoxicillin-resistant?Pseudomonas aeruginosa?ATCC-10145 was obtained with minimum inhibitory concentration (MIC) > 1000 μg.ml-1.?Streptomycesisolates were screened for producing β-lactamase inhibitory effect against?P. aeruginosaATCC-10145. There were ten?Streptomyces?isolates which had inhibitory effect. Although, one?Streptomyces?isolate has been considered the most potent, this was identified by using biochemical characteristics as?Streptomyces chromofuscus. Optimization factors for maximum yield of β-lactamase inhibitory protein were studied. The best incubation period at 7th day, incubation temperature at 28°C, pH value at 6.8, the best carbon source was galactose and the best nitrogen source was prolin. The highest amount of β-lactamase inhibitory protein was precipitated at 40% of saturated ammonium sulphate. The purification was carried out by using both diethyl-aminoethyl-cellulose and sephadex G-200 column chromatography, respectively. The β-lactamase inhibitory protein was separated at 32 kDa. The purified β-lactamase inhibitory protein was characterized as tazobactam. The combination of tazobactam at 128 mg.L-1?and amoxicillin at 125 μg.ml-1(in vitro) leads to growth inhibition of amoxicillin-resistant?P. aeruginosa?and make it very sensitive to the amoxicillin.