Isolation of Bacteriophage Effective against Shigella sonnei in Hospital and Municipal Wastewaters

Abstract

Background and Aim: Infections of antibiotic-resistant bacteria make their treatment difficult and sometimes impossible. So, scientists are looking for new solutions to fight these bacteria. Phage therapy can replace antibiotic therapy, especially in multidrug-resistant bacteria. Therefore, we aimed to isolate bacteriophage that is effective against common gram-negative bacteria. Materials and Methods: In this experimental study, 250 ml of hospital and municipal wastewater samples were gathered. The samples were centrifuged at 4000 rpm for 10 minutes, the supernatants were filtered through a 0.22 μm filter. To phage enrichment, 50 ml of filtered water twice the volume of nutrient broth and host bacteria were incubated at 37 C for 24 hours in a shaker incubator. The double-layer agar method was used to see bacteriophage plaque. Transmission electron microscopy was used to investigate the characteristics of the isolated bacteriophage. Results: Lytic bacteriophage effective to Shigella sonei was found by testing on municipal wastewater. Electron microscopy showed that the bacteriophage belonged to the family Microviridae. However, bacteriophage against other Gram-negative bacteria was not found in the test on hospital wastewater samples. Conclusion: The found bacteriophage had a specific lytic effect against Shigella sonei, this bacteriophage could be used for the study of phage therapy for Shigella infection with antibiotic resistance.