The in vitro antibacterial activity of ceftriaxone in comparison with nine other antibiotics.

The results of a large three centre co-ordinated study into the in vitro susceptibility of bacterial clinical pathogens showed no significant evidence of regional variation within the U.K. towards the 10 antibiotics examined. The newer cephalosporins were highly potent and superior to other antibiotics against the Enterobacteriaceae, with ceftriaxone and cefotaxime the most potent. Against Pseudomonas aeruginosa, gentamicin was the most active, followed by ceftazidime, piperacillin and ceftriaxone; cefotetan was the least active. Staphylococcus aureus and Staphylococcus albus were most susceptible to cefuroxime and gentamicin, though most were also susceptible to ceftriaxone, cefotaxime and cefoxitin. Streptococcus (Groups A and B), Streptococcus pneumoniae and Neisseria spp. were susceptible to most agents other than gentamicin, but ceftriaxone and cefotaxime were overall the most potent. Ceftriaxone was the most active agent against Haemophilus influenzae. The newer agents were variable and relatively poor against anaerobes and only amoxycillin and piperacillin were significantly active against Streptococcus faecalis. The overall resistance level to the third generation cephalosporins was low.