1977 Volume 25 Issue 1 Pages 12-19
In vitro and in vivo antimicrobial activities of mecillinam, a new semisynthetic penicillin were studied using various species of bacteria which were isolated from clinical specimens. The results obtained are summarized as follows.
(1) Mecillinam was found to be effective against Escherichia coli and Klebsiella pneumoniae, but ineffective against Pseudomonas aeruginosa. MBC (minimum bactericidal concentration) test has disclosed that the antibacterial action of the drug is bacteriostatic.
(2) Mecillinam was hydrolyzed by both Type I penicillinase and Type II penicillinase. But mecillinam was not hydrolyzed by penicillinase produced by both Pseudomonas aeruginosa and Staphylococcus aureus, but was ineffective against these strains.
(3) In vivo effect of mecillinam was examined by mice infected with E. coli. Mecillinam exhibited to be more effective than ampicillin, but dose response of this drug was weaker than that of ampicillin.
