In vitro susceptibilities to ampicillin, co-trimoxazole, cephalexin and amoxicillin/clavulanate of infecting bacteria isolated at Riyadh armed forces hospital

ABSTRACT

Increasing resistance is being demonstrated by many microorganisms to the commonly used oral antibiotics for out-patient therapy of infections. This resistance is mostly due to production of Beta lactamases. The in vitro activity of amoxycillin / clavulanate against 1026 commonly isolated Gram- positive and Gram-negative organisms from patients attending our hospital was determined and compared independently with amplicillin, co-trimoxazole and cephalexin. Amoxycillin / clavulanate showed better antimicrobial activity than ampicillin, co-trimoxazole and cephalexin against many more of the common organisms such as staphylococci, Haemophilus spp., Escherichia coli and Klebsiella. For the initial therapy of infections due to these organisms, amoxycillin / clavulanate appears to be a more appropriate choice, prior to the availability of microbiological results. It is hoped that these data will offer some auidance to physicians in the community who frequently have to deal with infections