[In vitro study of the bacteriostatic and bactericidal activity of temocillin (BRL 17421)].

Temocillin is a carboxypenicillin; a methoxy group in the 6-alpha position should confer to the molecule greater stability to beta-lactamases. 236 strains isolated from clinical specimens were tested. MICs were determined by agar dilution method. Enterobacteriaceae were very susceptible, MICs being generally less than or equal to 8 micrograms/ml and always less than 32 micrograms/ml. The activity of the drug was equal against the beta-lactamases producing strains. On the other hand temocillin was not active against aerobes (Pseudomonas aeruginosa and 90% of Acinetobacter), and against Gram positive bacteria. The bactericidal effect was strong: (formula; see text) A regression-line was proposed for Enterobacteriaceae and "break-points" were discussed.