Isolation and characterization of two lytic bacteriophages against Escherichia.coli and Salmonella entrica and evaluation of their antibacterial effects against different bacterial isolates from clinical infections in northwest of Iran

Majdani, Raheleh; Lamakan, Hamideh

doi:10.22034/cmr.2025.8336.3285

Isolation and characterization of two lytic bacteriophages against Escherichia.coli and Salmonella entrica and evaluation of their antibacterial effects against different bacterial isolates from clinical infections in northwest of Iran

Document Type : Research Paper

Authors

Raheleh Majdani

Hamideh Lamakan

Department of Biology, Faculty of Basic Sciences, University of Maragheh, Maragheh, Iran

10.22034/cmr.2025.8336.3285

Abstract

Introduction: Given the growing prevalence of antibiotic-resistant strains of bacteria, it is important to find suitable alternatives to antibiotics.

Materials and Materials: In this study, two lytic bacteriophages were isolated against Escherichia .coli and Salmonella enterica using bylayer-agar method and their biological and morphological characteristics were evaluated. Also, the effect of a number of environmental factors on these bacteria was investigated.

Results: The burst size and latent period of isolated phage against E. coli (PEcMa2/19) were 257 pfu/cell and four minutes, respectively, and the values for phage isolated against Salmonella enterica (PSeMa1/20) were 396 pfu/cell, and five minutes respectively. According to electron microscopy imaging, PEcMa2/19 and PSeMa1/20 were located in the Siphoviridae and Tectiviridae families. Both phages showed high stability to temperatures used. Higher phage survival rate of PEcMa2/19 and PSeMa1/20 were observed at pH = 5-7 and pH = 5-9, respectively. Phase PSeMa1/20 was more stable to UV exposure and both phages were highly resistant to osmotic shock. Isolated phage against E. coli had a lower host spectrum than PSeMa1/20 for the lysis of clinical isolates.

Conclusion: Due to the very suitable characteristics of each phase, after performing additional experiments including careful study of the host spectrum of each phage against the desired bacteria and molecular analysis of their genomes, they are recommended as candidates to fight bacterial problematic isolates.

Keywords

Antibiotic resistance

Bacteriophage

E.coli

Salmonella entrica

Subjects