N,N-dimethylglycyl-amido derivative of minocycline and 6-demethyl-6-desoxytetracycline, two new glycylcyclines highly effective against tetracycline-resistant gram-positive cocci.
The in vitro activities of the N,N-dimethylglycyl-amino derivative of minocycline (DMG-MINO) and 6-dimethyl-6-dexoxytetracycline (DMG-DMDOT), members of a new generation of tetracyclines, were evaluated by an agar dilution method and were compared with those of tetracycline and minocycline against 224 tetracycline-resistant and 73 tetracycline-susceptible recent clinical isolates of gram-positive cocci, including multiple-antibiotic-resistant methicillin-resistant Staphylococcus aureus and penicillin-resistant Streptococcus pneumoniae. The MICs of DMG-MINO and DMG-DMDOT were up to 500- to 2,000-fold lower than those of tetracycline against methicillin-resistant S. aureus and Streptococcus pneumoniae (MIC for 50% of strains tested [MIC50], < 0.06 microgram/ml). Against Streptococcus groups A, B, C, and G and Enterococcus faecalis, the MIC50 was 0.5 microgram/ml. MIC50s were greater only for coagulase-negative staphylococci (2 micrograms/ml). These data indicate that DMG-MINO and DMG-DMDOT are very potent drugs, and further in vitro and in vivo studies are warranted.
Goldstein
F W
FW
Laboratoire de Microbiologie Médicale, Hôpital Saint-Joseph, Paris, France.
Kitzis
M D
MD
Acar
J F
JF
D003030:Coagulase / Q000378:metabolism; D006095:Gram-Positive Cocci / Q000187:drug effects*; D006801:Humans; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000031:analogs & derivatives* / Q000494:pharmacology; D013210:Staphylococcus / Q000187:drug effects / Q000201:enzymology; D013291:Streptococcus / Q000187:drug effects; D013752:Tetracycline / Q000494:pharmacology; D013753:Tetracycline Resistance; D013754:Tetracyclines / Q000494:pharmacology*
D003030:Coagulase; D013754:Tetracyclines; C085305:9-(N,N-dimethylglycylamido)minocycline; C085306:6-demethyl-9-(N,N-dimethylglycylamido)-6-deoxytetracycline; D013752:Tetracycline; D008911:Minocycline