OP25-Isolation, characterization and potential application of bacteriophages for phage therapy

Background: Recent surge in the bacteriophage (bacterial viruses) research is indicative of their utility for various applications which include phage therapy for bacterial pathogens, rapid detection of bacteria and for other biotechnological purposes. The bacteriophages can be used as natural bio control, bio sanitation and bio preservation agents in food processing environment, pre harvest application in animals prior to slaughter and in rapid diagnostics. The bacteriophages specific to Vibrio cholerae were characterized for potential application in phage therapy.

Methods: Sewage samples were collected on two occasions from Seven Trent Sewage Works, Raynesway, Derby, a local wastewater treatment plant. The protocol used was modified from Van Twest and Kropinski, 2009. Two phages (Φ2 and Φ3) were obtained from Public Health England (PHE), London. The phages were characterized biologically (Lytic spectra and One step growth curve); physically (Electron Microscopy) and Genomically (PFGE and Restriction analysis).

Results: Bacteriophages could not be isolated through the sewage samples from the local wastewater treatment plant. The two phages obtained from PHE, London; Φ2 and Φ3 could could lyse 4.3% and 62.6% of the total 91 strains, respectively. The latent period and burst size of Φ2 were 14 ± 1.6 m and 06 ± 01 PFU/cell; while that of Φ3 were 13 ± 4.1 m and 54 ± 26 PFU/cell, respectively. Electron microscopy revealed that Φ2 was of Myoviridae family while Φ3 was of Siphoviridae family. The phage Φ2 had less than 48.5 kb genome; while Φ3 had larger genome of 114 kb. The restriction analysis could differentiate these phages.

Conclusions: Non availability of Vibrio cholerae specific phages in to the UK environment may be due to cholera being non existent in that country. Phages characterized have potential to be phage therapy candidates.