Bacteriophage Isolation, Characterization and Antibiofilm Effect Against Multidrug Resistant Gram Negative Bacteria Isolated from Intensive Care Units; Therapeutic Approach

OpenAlex İngilizce

The emergence of multidrug-resistant bacteria poses a significant global health challenge, particularly in intensive care settings. This study aimed to isolate, characterize, and evaluate the antibacterial and antibiofilm potential of lytic bacteriophages targeting clinical multidrug-resistant strains of Klebsiella pneumoniae , Escherichia coli and Pseudomonas aeruginosa . Phages were isolated from municipal wastewater samples collected in Iğdır, Turkey, using the double-layer agar method. The isolated phages MTBB P130581-D, MTBB E830-F, and MTBB K1467-F demonstrated specific lytic activity against their respective bacterial hosts. Transmission electron microscopy revealed morphological characteristics consistent with members of the Caudovirales order, including the Myoviridae , Siphoviridae and Podoviridae families. Phage stability was assessed under varying pH and temperature conditions. MTBB E830-F exhibited the highest pH tolerance, while MTBB K1467-F showed considerable thermal resistance. In vitro assays demonstrated significant reductions in planktonic bacterial populations (0.4–6 log CFU/mL) and biofilm mass, with the most substantial antibiofilm effects observed at lower bacterial dilutions and higher multiplicity of infection. Phage treatment reduced preformed biofilms by up to 90.4% in P. aeruginosa , 78.3% in K. pneumoniae , and 62.5% in E. coli . These findings underscore the potential of phage therapy as an effective strategy for combating multidrug-resistant infections and biofilms in clinical settings. The phages isolated in this study expand the existing phage repertoire and offer promising alternatives to traditional antibiotics, especially against hard-to-treat nosocomial pathogens.