[Activity of new beta-lactam antibiotics].

The antibacterial activity of the newer beta-lactam compounds mezlocillin, cefuroxime, cefotaxime, ceftizoxime, cefoperazone, lamoxactam, and cefsulodin was evaluated in 335 strains of ampicillin-resistant (MIC greater than 16 mg/l) enterobacteria, 50 pseudomonas aeruginosa, 28 acinetobacter species, and 50 streptococcus faecalis isolates. With the exception of some strains, enterobacteria were inhibited by low levels of cefotaxime and ceftizoxime, respectively. Between these both compounds there was an almost complete cross-resistance. In each species lamoxactam inhibited at least 90% of the isolates. The antibacterial activity of cefoperazone against enterobacteria was decreased; however, it was active against pseudomonas aeruginosa exhibited antibacterial activity comparable to that of azlocillin. Cefsulodin proved to be the most active drug against pseudomonas aeruginosa exceeding to some extent even piperacillin. Ceftizoxime was the most active drug against acinetobacter species. Among the new cephalosporins, it was only cefoperazone that exhibitediting antibacterial activity comparable to that of azlocillin. Cefsulodin proved to be the most active drug against pseudomonas aeruginosa exceeding to some extent even piperacillin. Ceftizoxime was the most active drug against acinetobacter species. Among the new cephalosporins, it was only cefoperazone that exhibitediting antibacterial activity comparable to that of azlocillin. Cefsulodin proved to be the most active drug against pseudomonas aeruginosa exceeding to some extent even piperacillin. Ceftizoxime was the most active drug against acinetobacter species. Among the new cephalosporins, it was only cefoperazone that exhibited some activity against streptococcus faecalis, which was comparable to that of cephalothin, but markedly impaired to that of cefazedone. With respect to streptococcus faecalis, the penicillin derivatives still remain the by far most active compounds.