IN VITRO ACTIVITY OF AMPICILLIN AGAINST BETA LACTAMASE PRODUCERS

Abstract

This study was carried out in Khartoum State, during August to October 2005. The study was designed to evaluate in vitro activity of ampicillin against β-lactamase producers. Two hundred clinical specimens were collected. 38.5% of the specimens were ear swabs, 36.5% wound swabs, and 25% urine. Cultivation of these specimens on enriched and / or differential media yielded isolation of 189 isolates. β-Lactamase producers were detected by β-lactamase acidimetric method. Result showed that positive isolates were S.aureus (31.9%), E.coli (21.6%), Ps. aeruginosa (16.4%), K. pneumoniae (15.5%), P.mirabilis (13.7%) and P. vulgaris (0.9%). Ampicillin activity against β-lactamase determined by using National Committee for Clinical Laboratory Standards (NCCLS) modified Kirby- Bauer Disc Diffusion technique. The result revealed that only 8.6% of the β-lactamase producers were sensitive to ampicillin while 91.4% were resist the action of ampicillin.