Characterization of Some Induced Phages Specific for Two Bacteria Isolated from Potato Naturally Infected with Soft Rot Disease

Abstract

Background: U.V irradiation was used for indication of temperate phages of Serratia marcescens. The RAPD-PCR was used for quick typing detection of phage isolates from different bacteria. Aims: This study aims to isolate and identify some pathogenic bacteria from potato naturally infected with soft rot disease. In addition, the temperate phages were induced by U.V irradiation from the isolated pathogenic bacteria. Materials and Methods: U.V irradiation was used to isolate temperate phages from the pathogenic bacteria. Biological and molecular experiments were used to characterize and identify the induced phage isolates. Results: Two bacterial isolates were isolated from a potato tuber showing soft rot symptoms. These two isolates were identified as Serratia marcescens ss marcescens and Entrobacter cloacae ss dissolvens. Both of the isolated bacteria were found to be lysogenic bacteria. Two temperate phages designated SmI and EdI were induced from Serratia marcescens ss marcescens and Entrobacter cloacae ss dissolvens, respectively, using U.V irradiation. Electron micrographs of the two induced phages indicated that the particles of both phages have hexagonal icosahedral heads and contractile tails. The two induced phages were found to have a narrow host range. In RAPD-PCR, sixteen bands were unique polymorphism DNA products with six primer used. The size of all the amplified fragments ranged from 288 to 1588 bp. Conclusion: The results of this study indicated that Serratia marcescens ss marcescens and Entrobacter cloacae ss dissolvens were found to contain prophages. The temperate phages were induced by U.V irradiation from Serratia marcescens ss marcescens and Entrobacter cloacae ss dissolvens and designated SmI and EdI, respectively.