The antimicrobial peptide Tachyplesin III coated alone and in combination with intraperitoneal piperacillin-tazobactam prevents ureteral stent Pseudomonas infection in a rat subcutaneous pouch model Daniele Minardi a, *, Roberto Ghiselli b , Oscar Cirioni c , Andrea Giacometti c , Wojciech Kamysz d , Fiorenza Orlando e , Carmela Silvestri c , Gianni Parri a , Elzbieta Kamysz f , Giorgio Scalise c , Vittorio Saba b , Muzzonigro Giovanni a a Institute of Maternal and Children’s Sciences-Urology, Polytechnic University of the Marche Region, A.O. Ospedali Riuniti, 60020 Ancona, Italy b Department of General Surgery, I.N.R.C.A. I.R.C.C.S., Polytechnic University of the Marche Region, Ancona, Italy c Institute of Infectious Diseases and Public Health, Polytechnic University of the Marche Region, Ancona, Italy d Faculty of Pharmacy, Medical University of Gdan ´ sk, Poland e Experimental Animal Models for Aging Units, Research Department, I.N.R.C.A. I.R.C.C.S., Ancona, Italy f Faculty of Chemistry, University of Gdan ´ sk, Poland 1. Introduction The use of synthetic materials for the insertion of temporary or permanent implants in the body, i.e. intravascular catheters, urinary catheters, etc., has been accompanied by the emergence of implant-associated infections that represent an important cause of morbidity [1,10]. Bacterial infections caused by biofilm formation on indwelling urinary catheters and double-J ureteral stents are well known complications in urological practice and several studies have demonstrated the direct correlation between the use of medical devices, the peptides 28 (2007) 2293–2298 article info Article history: Received 7 September 2007 Received in revised form 29 September 2007 Accepted 1 October 2007 Published on line 7 October 2007 Keywords: Peptides Tachyplesin III Ureteral stents Bacterial adhesion Urinary tract infections Biofilm abstract We investigated the efficacy of Tachyplesin III alone or combined with piperacillin-tazo- bactam (TZP) to prevent biofilm formation in vitro and in a rat model of Pseudomonas aeruginosa ureteral stent infection. We have observed that in vitro TZP, in presence of Tachyplesin III, showed minimal inhibitory concentrations (MIC)s twofold and minimal bactericidal concentrations (MBC)s eightfold lower. The in vivo study showed that rats that received intraperitoneal TZP showed the lowest bacterial numbers. Tachyplesin III com- bined with TZP showed efficacies higher than that of each single compound. Coating ureteral stents with Tachyplesin III is able to inhibit bacterial growth up to 1000 times. # 2007 Elsevier Inc. All rights reserved. * Corresponding author. Tel.: +39 071 5965667; fax: +39 071 5963367. E-mail address: d.minardi@univpm.it (D. Minardi). available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/peptides 0196-9781/$ – see front matter # 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.peptides.2007.10.001