Ramoplanin (
A-16686/MDL 62,198) is a novel
lipoglycopeptide antimicrobial, comprised of three closely related
polypeptides containing chlorinated phenyl moieties and
D-mannose, isolated from the fermentation products of Actinoplanes sp. ATCC 33076. The antimicrobial activity of
ramoplanin is limited to Gram-positive bacteria and its reportedly unacceptable administration side-effects suggest that any potential clinical role will be limited to the topical
therapy of superficial skin
infections and the eradication of bacteria, representing a possible nosocomial
cross-infection source, from carriage sites. In this study the MICs of
ramoplanin have been determined for
methicillin-susceptible and methicillin-resistant isolates of Staphylococcus aureus, S. epidermidis and S. haemolyticus and compared with those of two
glycopeptide antimicrobials,
vancomycin and
teicoplanin. MICs were determined using an
agar incorporation technique in Mueller-Hinton medium with an inoculum of 10(5) cfu.
Ramoplanin was 2-8 times more active than either
vancomycin or
teicoplanin against
methicillin-susceptible and methicillin-resistant isolates of S. aureus and
methicillin-susceptible isolates of S. epidermidis. Isolates of methicillin-resistant S. epidermidis and both
methicillin-susceptible and -resistant isolates of S. haemolyticus were generally less susceptible to
teicoplanin than to
vancomycin.
Ramoplanin was significantly more active than either
vancomycin or
teicoplanin against these isolates. These results suggest that the clinical evaluation of
ramoplanin as a topical
antibacterial agent for the control of superficial
infections caused by Staphylococcus spp. and for the eradication of methicillin-resistant S. aureus from carriage sites, is justified.