Comparative antibacterial activity of the penem ALP 201.

The minimum inhibitory concentration (MIC) of the new penem ALP 201 was tested against 243 recent clinical isolates of which 95 were from the family Enterobacteriaceae, 50 were from the genus Streptococcus, 50 were Staphylococcus aureus and 48 were Staphylococcus epidermidis. An agar dilution technique was used to determine the MIC50 and MIC90 of ALP 201 in comparison with cefotaxime, cefuroxime, clindamycin, imipenem, piperacillin, tobramycin and vancomycin. Overnight cultures were suspended to produce inocula of 10(5) colonies from a replicator. ALP 201 was shown to have an activity similar to imipenem against most species; ALP 201 was less active than imipenem against Serratia spp. and was more active against S. epidermidis. beta-Lactamase production did not affect the activity of ALP 201. All the other compounds tested were less active than ALP 201 and imipenem.