Novobiocin

Novobiocin, also known as albamycin or cathomycin, is an aminocoumarin antibiotic that is produced by the actinomycete Streptomyces niveus, which has recently been identified as a subjective synonym for S. spheroides a member of the order Actinobacteria . Other aminocoumarin antibiotics include clorobiocin and coumermycin A1. Novobiocin was first reported in the mid-1950s (then called streptonivicin).

Clinical use

It is active against Staphylococcus epidermidis and may be used to differentiate it from the other coagulase-negative Staphylococcus saprophyticus, which is resistant to novobiocin, in culture.

Novobiocin was licensed for clinical use under the tradename Albamycin (Pharmacia And Upjohn) in the 1960s. Its efficacy has been demonstrated in preclinical and clinical trials. The oral form of the drug has since been withdrawn from the market due to lack of efficacy. Novobiocin is effective antistaphylococcal agent used in the treatment of MRSA.

Mechanism of action

The molecular basis of action of novobiocin, and other related drugs clorobiocin and coumermycin A1 has been examined. Aminocoumarins are very potent inhibitors of bacterial DNA gyrase and work by targeting the GyrB subunit of the enzyme involved in energy transduction. Novobiocin as well as the other aminocoumarin antibiotics act as competitive inhibitors of the ATPase reaction catalysed by GyrB. The potency of novobiocin is considerably higher than that of the fluoroquinolones that also target DNA gyrase, but at a different site on the enzyme. The GyrA subunit is involved in the DNA nicking and ligation activity.