The Biological Characters Of Pseudomonas Aeruginosa Phage PaP3 And The Identification Of Its Integrated Site

Bacteriophage is of a bacterial virus which is ubiquitous in nature. When the sensitive bacterium was infected by a phage, there will be two reactions, one is lytic reaction, the other is lysogenic reaction. Lysogenic phage genome can integrate into its sensitive bacterial chromosome to be a prophage, which is a common phenomenon in nature.The lysogenic bacteriophage can alter the biologic features of the host bacterium by its inheritance material, meanwhile, they can change host's inheritance material constituent in the process of the DNA recombination, integration, transposition and excision in host genome, which result in the microbial genetic diversity. For example, transfer of virulence gene and transmission of drug-resistant gene mediated by a phage results in gene polymorphism of bacteria, which is an important problem in medicine and genetics. So it is important to study attachment site and the mechanism of integration. It will be of value in investigating gene flow between different species. Integration of lysogenic phage genome into its sensitive bacterial chromosome is a potent integration system based on phage integrase. For Pseudomonas aeruginosa phages, only phage D3 and Pf1 integrase was identified. The mechanism of integration of a phage genome into Pseudomonas aeruginosa chromosome by integrase has not been illustrated. In 2000, Stover and his colleagues completed the genomic sequencing and annotating of Pseudomonas aeruginosa strain PA01, which make the foundation of investigating lysogenic mechanism of Pseudomonas aeruginosa phages. In this study, we focused on the lysogenic phage PaP3 of Pseudomonas aeruginosa. First, the lysogenization conditions and biological characters of the phage PaP3 were investigated. And then, the attachment site of phage PaP3 within the genome of PA3 was identified. This study makes the foundation of investigating the biological properties and lysogenic mechanisms of Pseudomonas aeruginosa phage PaP3. The contents and results are as follows:...