IN-VITRO ACTIVITY OF MDL-62,879 AGAINST GRAM-POSITIVE BACTERIA AND BACTEROIDES SPECIES

The new thiazolyl peptide antibiotic MDL 62,879 (GE2270 A) showed exce llent in vitro activity in testing against staphylococci and streptoco cci, with MIC90s ranging from 0.23 to 0.9 mg/l. It was very active aga inst Clostridium difficile and Propionibacterium acnes (MIC90 0.06 mg/ l in each case) and had variable activity against Bacteroides sop. MDL 62,879 had exceptionally good activity against Enterococcus faecalis, including against a collection of high-level aminoglycoside-resistant isolates where it had an MIC90 of 0.047. The antibiotic was bacterios tatic for enterococcal isolates but bactericidal for a methicillin-res istant isolate of Staphylococcus aureus.