- 期刊
Effect of Sulbactam on the Antibacterial Activity of Ampicillin against Various Clinical Isolates from Ntuh
並列摘要
It has been well-established that the induction of β-lactamase is the major mechanism by which many clinical microbes exhibit their resistance to β-lactam antibiotics. A total of 112 clinical isolates including 92 of Gram-negative bacilli and 20 of Gram-positive cocci were studied for their β-lactamase production. Their susceptibilities to ampicillin in the presence or absence of sulbactam, a semisynthetic β-lactamase inhibitor, were examined. The susceptibility was determined by broth dilution method, and the recently developed fluorescent spot test was employed for the detection of β-lactamase. In conclusion, sulbactam alone had only weak antiboacterial activity, but it could enhance dramatically the activity of ampicillin. The minimal inhibitory concentratioin (MIC) of ampicillin combined with sulbactam in a ratio of 2:1 was always lower (2.5-14 folds) than that of ampicillin alone. The sulbactam was found to be a competitive inhibitor toward the purified β-lactamase of Escherichia coli NTUH 9501-1.