The in nitro antibacterial activity of cefotaxime compared with that of cefuroxime and cefoxitin

Abstract

The activity and susceptibility to hydrolysis by β-lactamases of cefotaxime was compared with that of other β-lactam antibiotics. Cefotaxime was the most active of the cephalosporins against aerobic Gram-negative bacteria. Its activity was particularly notable against the Enterobacteriaceae with 90% of isolates from cephaloridine-susceptible species inhibited by 0.062 mg/1 and the same proportion of isolates from cephaloridine-resistant species inhibited by 0.5 mg/1 No isolates of Enterobacteriaceae were resistant to cefotaxime yet susceptible to cefuroxime or cefoxitin. It was also very active against Haemophilus influenzae and Neisseria gonorrhoeae. Cefotaxime was not so active against Acinetobacter spp. but was still the most active cephalosporin. It was about fourfold more active than carbenicillin against Pseudomonas aeruginosa but was much more active than carbenicillin against most highly carbenicillin-resistant isolates. Other species of Pseudomonas varied in their susceptibility to cefotaxime but it was generally the most active cephalosporin. Cefotaxime was slightly more active than ampicillin but slightly less active than cefoxitin against the Bacteroides fragilis group of anaerobes. Other anaerobes were more frequently susceptible to β-lactam antibiotics and major differences between cefotaxime, cefoxitin and ampicillin were not noted. Cefotaxime possessed similar high activity to cephaloridine and benzylpenicillin against most streptococci but was appreciably less active than cephaloridine against Streptococcus faecalis as well as against staphylococci. Cefotaxime was resistant to most β-lactamases but was hydrolysed by the enzymes produced by Proteus vulgaris and B. fragilis.