In-vitro activity of imipenem to pseudomonas and other gram negative bacteria

The agar dilution technique was used to determine the minimum inhibitory concentration [MIC] of imipenem to clinical isolates from hospital and community acquired infections. From 160 strains of pseudomonas tested, 76% were sensitive to 6 Ug/ml or less, of which 66% had MIC of 4Ug/ml. There was 10% resistance as defined by growth at higher than 8 Ug/ml. Most escherichia coli strains [90%] were sensitive to 2 Ug/ml or less, while 13% of klebsiella strains showed resistance to 8 Ug/ml. The overall resistance in all strains was 9%