Author/Authors :
Shokri، Dariush نويسنده Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, IR Iran , , Rabbani-Khorasgani، Mohammad نويسنده Department of Biology, Faculty of Sciences, University of Isfahan, Iran. Rabbani-Khorasgani, Mohammad , Zaghian، Saeideh نويسنده Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, IR Iran , , Fatemi، Seyed Masih نويسنده Department of Microbiology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, IR Iran , , Mohkam، Milad نويسنده Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran , , Ghasemi، Younes نويسنده Pharmaceutical Sciences Research Center, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran , , Taheri-Kafrani، Asghar نويسنده Department of Biotechnology, Faculty of Advanced Sciences and Technologies, University of Isfahan, Isfahan, IR Iran ,
Abstract :
The emergence of pan-drug resistant strains (PDR) of Pseudomonas aeruginosa has led to renewed efforts to identify alternative agents, such as bacteriocins and bacteriocin-like inhibitory substances (BLISs). The aims of this study were to determine the acquired resistance profiles of multidrug-resistant (MDR), extensively drug-resistant (XDR), and PDR P. aeruginosa isolates based on the revised definitions of the CDC and ECDC and to screen and characterize effective BLISs against these isolates. In a cross-sectional study, 96 P. aeruginosa strains 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 the P. aeruginosa strains was characterized based on its physicochemical properties, size, growth curves, and production profiles. Among the 96 isolates of P. 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 the P. aeruginosa DSH22 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. This BLIS with broad-spectrum activity may be a potential agent for the treatment or control of drug-resistant strains of P. aeruginosa infection.
