title: Determination of Acquired Resistance Profiles ofPseudomonas aeruginosaIsolates and Characterization of an Effective Bacteriocin-Like Inhibitory Substance (BLIS) Against These Isolates.
abstract: BACKGROUND
  The emergence of pan-drug resistant strains (PDR) ofPseudomonas aeruginosahas led to renewed efforts to identify alternative agents, such as bacteriocins and bacteriocin-like inhibitory substances (BLISs).
  
  
  OBJECTIVE
  The aims of this study were to determine the acquired resistance profiles of multidrug-resistant (MDR), extensively drug-resistant (XDR), and PDRP. aeruginosaisolates based on the revised definitions of the CDC and ECDC and to screen and characterize effective BLISs against these isolates.
  
  
  METHODS
  In a cross-sectional study, 96P. aeruginosastrains were isolated during a 12-month period. The resistance profiles of these isolates were determined as MDR, XDR, and PDR, and the data were analyzed using WHONET5.6 software. A BLIS against theP. aeruginosastrains was characterized based on its physicochemical properties, size, growth curves, and production profiles.
  
  
  RESULTS
  Among the 96 isolates ofP. aeruginosa, 2 (2.1%), 94 (97.9%), and 63 (65.6%) were non-MDR, MDR, and XDR, respectively, and 1 (1.1%) was PDR. The most effective antibiotics against these isolates were polymyxins and fosfomycin. A BLIS isolated from theP. aeruginosaDSH22 strain had potent activity against 92 (95.8%) of the 96 isolates. The BLIS was heat stable, (up to 100°C for 10 min), UV stable, and active within a pH range of 3 - 9. The activity of BLIS disappeared when treated with trypsin, proteinase K, and pepsin, indicating its proteinous nature. Based on its size (25 kDa), the BLIS may belong to the large colicin-like bacteriocin family. BLIS production started in the midexponential phase of growth, and the maximum level (2700 AU/mL) occurred in the late-stationary phase after 25 hours of incubation at 30°C.
  
  
  CONCLUSIONS
  This BLIS with broad-spectrum activity may be a potential agent for the treatment or control of drug-resistant strains ofP. aeruginosainfection.
authors: Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, IR Iran.
authors: Dariush
authors: D
authors: Shokri
authors: Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, IR Iran.
authors: Mohammad
authors: M
authors: Rabbani Khorasgani
authors: Nanobiotechnology Department, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, IR Iran.
authors: Saeideh
authors: S
authors: Zaghian
authors: Department of Microbiology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, IR Iran.
authors: Seyed Masih
authors: SM
authors: Fatemi
authors: Department of Pharmaceutical Biotechnology, Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors: Milad
authors: M
authors: Mohkam
authors: Department of Pharmaceutical Biotechnology, Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, IR Iran.
authors: Younes
authors: Y
authors: Ghasemi
authors: Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan, IR Iran.
authors: Asghar
authors: A
authors: Taheri-Kafrani
keywords: Antibiotic Resistance; Bacteriocin-Like Inhibitory Substance; Multidrug Resistant (MDR); Pseudomonas aeruginosa