Iranian Journal of Medical Microbiology

Background and Aim: The high occurrence rate of antibiotic-resistant Helicobacter (H.) pylori has led to consideration of novel therapeutic approaches. This study aimed to isolate and characterize a bacteriophage against antibiotic-resistant strains of H. pylori isolates from gastric biopsies of patients.
Materials and Methods: Untreated wastewater was collected from Imam Hossein, Taleghani, and Mofid Children’s Hospitals and mixed together. The presence of bacteriophage was confirmed by double-layer agar technique. Transmission Electron Microscope (TEM) was used to determine the morphology of the isolated phage. In addition, stability tests were performed. The host range and multiplicity of infection (MOI) of bacteriophages were determined. Finally, the phage genome was extracted and its concentration was calculated using a Nanodrop spectrophotometer.
Results: TEM micrograph showed that the isolated phage belonged to the Caudoviricetes class and had Podoviridae-like morphology. It was effective against 9 clinical strains of H. pylori and the standard strain of Campylobacter jejuni. The optimal activity of this phage was at 37°C and pH 4 to 7. This phage was sensitive to chloroform, and was stable with increasing salt concentration. It was revealed that MOI=1 was optimal for this bacteriophage activity.
Conclusion: In conclusion, the isolated phage was effective against antibiotic-resistant strains of H. pylori isolates from gastric biopsies of patients. It can be considered a suitable candidate for further genomic and in vivo studies.