In vitro resistance to daptomycin of staphylococcus aureus and enterococcus spp. strains

Daptomycin is the first antibiotic in a new class of cyclic lipopeptides, active in vitro against Gram - positive cocci. The mechanism of action is a rapid depolarization of the bacterial membrane potential, loss of cytoplasmic contents, mainly K+ ions and inhibition of protein, DNA and RNA synthesis, followed by the bacterial cell death. There were investigated 112 strains of Gram-positive cocci recommended for daptomycin susceptibility testing. Since the main clinical indications of daptomycin are the severe skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus, vancomicin-resistant enterococci and penicillinresistant Streptococcus spp, we tested daptomycin activity only in these species