[1] Univ Cologne, Klinikum Merheim, Dept Surg 2, Cologne, Germany
[2] Univ Cologne, Klinikum Merheim, Microbiol Lab, Cologne, Germany
[3] Univ Cologne, Fac Med, Biochem & Expt Div, Cologne, Germany
[4] Univ Cologne, Inst Sci Evaluat & Naturopathy, Cologne, Germany
[5] Univ Cologne, Inst Med Microbiol & Hyg, D-5000 Cologne, Germany
[6] Rhein Westfal TH Aachen, Dept Anesthesiol, Aachen, Germany
[7] Heidelberg Univ, Inst Med Microbiol & Hyg, Heidelberg, Germany
[8] Heidelberg Univ, Dept Anesthesiol, Heidelberg, Germany
[9] CAESAR, Bonn, Germany