In vitro antimicrobial activity of the thiazolyl peptide antibiotic MDL 62,879 (GE2270 A)

Compound MDL 62,879 (GE2270 A) is a thiazolyl peptide antibiotic that appears to inhibit aminoacyl-tRNA binding to elongation factor Tu. In the present study, it was shown that MDL 62,879 broth microdilution MIC values were generally 2-4 doubling dilutions lower in the presence of 0.02% bovine serum albumin. Using US clinical isolates and BSA-supplemented media, MDL 62,879 was more active than teicoplanin and vancomycin against the staphylococci and glycopeptide-resistant and glycopeptide-susceptible enterococci and equally active against the streptococci. Broth microdilutions MIC values were not appreciably affected by inoculum concentrations of 5 x 10(4) to 5 x 10(8) cfu/ml or in the presence of 3.5% human serum albumin.