2.2.3. Determination of MRSA

MRSA isolates were characterized for their resistance pattern by susceptibility testing according to EUCAST (EUCAST V2.0, 2012), tested with penicillin (P), cefoxitin (FOX), tetracycline (TE), erythromycin (E), clindamycin (CL), norfloxacin (NOR), amicazin (AN), gentamicin (GM), trimethoprim/sulfamethoxazole (SXT), fusidic acid (FA), rifampicin (RIF), linezolid (LZD) and mupirocin (MUP) using BD BBLTM Sensi-DiscTM paper discs (BD, Sparks, MD, USA). *Staphylococcus aureus* DSM799 was used as reference. PCR amplification was used to determine SCC*mec* type and presence of the Panton-Valentine-Leukozidin (PVL)-gene [26,27]. *Spa* typing was performed as described previously [28].

#### **3. Results**

All eleven investigated sludge samples revealed at least one kind of the screened multiresistant bacteria. In detail, ten of the eleven samples were positive for ESBL-harbouring Enterobacteriacea (82%), three samples were positive for MRSA (27%) and four samples for VRE (36%).
