Comparative in vitro antimicrobial activity of vancomycin, teicoplanin, daptomycin and ceftobiprole in four different...

Peritoneal dialysis used in the treatment of patients with end-stage renal failure is often complicated by peritonitis. Staphylococcus aureus peritonitis is severe, particularly if caused by a methicillin-resistant strain (MRSA). Intraperitoneal administration of drugs for treatment of peritonitis is preferable to intravenous or oral routes because of the resulting higher local antibiotic concentrations. However, peritoneal dialysis fluids (PDFs) have a bacteriostatic effect, which may compromise the efficacy of antibiotics. The bactericidal efficacy of vancomycin, teicoplanin, daptomycin and ceftobiprole was studied in the PDFs Dianeal PD4® (glucose 1.36%), Physioneal 40® (glucose 1.36%), Extraneal® (7.5% icodextrin), and Nutrineal PD4® (1.1% amino acid) using time-kill curves. To simulate in vivo conditions, human serum albumin was added at a final concentration of 2 g/l. All four PDFs had a bacteriostatic effect on the growth of the MRSA test isolate. All antibiotics showed less activity in PDFs compared to control broth. Vancomycin and teicoplanin achieved the greatest reduction in bacterial numbers in the amino-acid containing PDF Nutrineal PD4®. Daptomycin showed its highest activity in Extraneal® and better overall efficacy than the other tested antibiotics. Ceftobiprole showed no killing activities in any of the four PDFs. Based on these in vitro data we conclude that the choice of PDFs for intraperitoneal administration is not trivial and could be crucial for therapy outcome.