IN-VITRO ACTIVITY OF WY-49605, A PENEM ANTIMICROBIAL

The in vitro activity of the penem antimicrobial WY-49605 was compared with those of other agents available for oral administration. Based o n concentrations inhibiting 90% of isolates (MIC(90)s), the penem inhi bited methicillin-susceptible staphylococci (MIC(90) = 0.25 mu g/ml), penicillin-susceptible streptococci (MIC(90) less than or equal to 0.1 2 mu g/ml) and several other Gram-positive genera at concentrations co mparable or superior to the most active comparison agents. WY-49605 an d cefpodoxime were the most active agents against members of the famil y Enterobacteriaceae. Most strains of Enterococcus faecalis and Bacter oides fragilis were susceptible to the new agent at concentrations les s than or equal to 4 mu g/ml, while Pseudomonas aeruginosa, Enterococc us faecium, and methicillin-resistant Staphylococcus aureus were resis tant to all agents tested.