Isolation and characterization of bacteriophage against “Escherichia coli” causing urinary tract infection

BACKGROUND AND OBJECTIVESUrinary tract infection (UTI) is one of the most common bacterial infections. The investigations estimated that ۸۰% of UTI are caused by “Escherichia coli” bacteria. The global decrease in the effectiveness of antibiotics in the treatment of bacterial infections has created a new interest in the use of bacteriophages in the treatment of infections. The purpose of this research was to isolate and identify bacteriophage effective on E. coli straind isolated from UTI.MATERIALS AND METHODSE. coli strains isolated from urine specimens of patients with UTI, their antibiotic susceptibility was obtained from the clinical microbiology laboratory at the Mofid hospital. They were confirmed as UPEC with the help of biochemical and PCR methods. in this study, the phage was isolated from Mofid hospital sewage, and spot test were used for validation of phage presence. Then the phage was purified and enriched using the double layer agar techniques. To determine the morphology of the isolated phage the Transmission Electron Microscopy (TEM) was used. The effect of environmental factors on the phage such as thermal stability, pH effect and stability in the presence of chloroform and different concentrations of NaCl was determined.RESULTS AND DISCUSSIONIsolating bacteriophage had the ability to create suitable plaques and lyse bacteria. Based on the TEM results, the isolated phage had a large polyhedral head and a short retractable tail, belonging to the Myoviridae family. The isolated phage had the best activity at ۳۷°C. The phage has a suitable lytic activity at pH ۷, inactivation phage was observed in ۷۰°C and PH ۱۴. Phage lytic activity increased with increasing NaCl concentration (۵%-۱۰%-۱۵%). The phage was resistant to chloroform.CONCLUSIONThe isolated bacteriophage had a specific lytic activity against E. coli caused UTI. This phage can be used in phage therapy as an alternative treatment for people with UTIs which are resistant to antibiotics.

کلیدواژه ها:

Bacteriophage ، Escherichia coli ، Phage therapy ، Urinary Tract Infection