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

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.

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.

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.

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.