In spite of improvements in surgical techniques and medical therapy, the frequency of mediastinitis has remained stable during the last years . Therefore, therapy of mediastinitis after cardiothoracic surgery seems to be a challenging problem .
Staphylococcus aureus is the most common isolated germ in patients developing mediastinitis . Unfortunately, Staphylococcus aureus has become an evolving management problem, because of an increasing number of antibiotic resistance and MRSA infections which causes high rates of morbidity and mortality [12, 13].
Vancomycin is still the antibiotic therapy of choice for the treatment of infections caused by MRSA. However, the therapy with vancomycin may be contraindicated in a number of cases (e.g. renale failure) and ineffective in numerous cases because of limited tissue penetration . Furthermore, Staphylococcus aureus (including MRSA) exhibits a declining susceptibility to vancomycin during the last years . Thus, the need for alternative antibiotic therapies as supportive therapy after surgical debridement has become apparent .
An alternative antibiotic option seems to be linezolid, because linezolid eradicates MRSA better than vancomycin in complicated skin or soft-tissue infections caused by MRSA. Furthermore, linezolid reduces the length of hospitalization in these patients . Despite the advantages of linezolid, concerns about safety and costs often limit its use.
Daptomycin is a cyclic lipopeptide antibiotic with bactericidal activity against gram-positive organisms in a concentration-dependent manner . In patients with (gram-positive) wound infection, daptomycin is useful in more than 90%  which is comparable to success rates found for vancomycin (87%) and linezolid (93%). Furthermore, eradication of bacterial infections by daptomycin amounts 96% in the case of MRSA, 92% in the case of coagulase-negative staphylococci, and 88% in the case of Enterococcus species [16, 17].
The efficiency of daptomycin is consistent with the pharmacokinetic profile of this drug. Daptomycin exhibits excellent penetration of subcutaneous tissue levels in healthy volunteers (averaging 74% of plasma levels) and inflammatory tissues (averaging nearly 70% of plasma levels) . Although daptomycin penetrates the tissue rapidly, disappearance is relatively slow, with an elimination half-life of more than 17 hours [6, 16, 17].
Daptomycin is highly effective in the treatment of bacteraemia and endocarditis caused by MRSA and several reports document its effectiveness in infections related to cardiac surgery [8, 18]. Based on these observations, we analysed the role of daptomycin as new treatment option as supportive treatment to surgical therapy in patients developing mediastinitis after cardiac surgery. Within our study, we found clinical success in more than 90% when daptomycin was combined with surgical therapy. The patients responded to daptomycin therapy commonly after 5 days. Daptomycin was well tolerated in the present study which is in accordance to previous studies. The patients may benefit by the fact, that daptomycin is able to penetrate into device-adhering biofilms better than other antibiotics . However, controlled prospective studies are necessary to evaluate the optimal surgical and antibiotic regime in these patients