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.
