Main outcome variable: The cefpirome and moxifloxacin concentrations in abscess fluid will be measured. Considering plasma PK and the ratio of the surface to volume ratio of the abscess, the individual concentration-versus-time curve in abscess (cyst) fluid will be calculated. Individual pharmacokinetic parameters will be determined for abscess (cyst) fluid after a single dose and at steady state: AUC, AUC0-12/24h, Cmax, Tmax, t1/2ß, Cav(ss).