Background and objective: Multi-resistant coagulase-negative staphylococci (CNS) may cause systemic infections in patients undergoing bone marrow transplantation. Daptomycin, a new lipopeptide, and tigecycline, a new glycylcycline, have excellent activity against Gram-positive bacteria including methicillin-resistant staphylococci. This study presents the in vitro activity of daptomycin and tigecycline compared to vancomycin and fosfomycin against 105 CNS isolated from 76 bone marrow transplant patients with symptomatic bacteremia.
Material and methods: Blood stream isolates of Staphylococcus epidermidis (n = 102) and Staphylococcus haemolyticus (n = 3) from bone marrow transplant patients were collected from 2000 to 2006. The susceptibility of all isolates was tested using methods of the Clinical Laboratory Standards Institute.
Results: The minimal inhibitory concentrations MIC(50) and MIC(90) were 0.125 microg/mL and 0.25 microg/mL for daptomycin, 0.25 and 0.5 microg/mL for tigecycline, 1 microg/mL and 2 microg/mL for vancomycin, and 8 microg/mL and >256 microg/mL for fosfomycin, respectively. MIC values of tested agents were similar for both methicillin-sensitive and methicillin-resistant S. epidermidis strains.
Conclusions: All CNS isolates were susceptible to the new antistaphylococcal agents daptomycin and tigecycline. Although vancomycin had been used over the past 30 yr at our bone marrow transplant unit all CNS were still susceptible to vancomycin.