In vitro comparison of the activity of cefotaxime and desacetylated cefotaxime and of their combination.

The activity of cefotaxime (CTX), desacetylcefotaxime (dCTX) and their combinations (CTX and dCTX in a 1:1 ratio) was tested against a variety of aerobic and anaerobic bacteria collected from clinical specimens. The in-vitro tests demonstrated that CTX is still active against a wide range of clinically interesting microorganisms. The interaction of CTX and dCTX was shown to be additive at subinhibitory and inhibitory concentrations for Enterobacteriaceae. The most significant increase in the antibacterial activity was seen against Bacteroides strains: 29% of 62 strains were sensitive to CTX and 38% to CTX plus dCTX.