Title Phenotypic Characterization and Genomic Analysis of the Shigella sonnei Bacteriophage SP18
Author Kyoung-Ho Kim1, Ho-Won Chang2, Young-Do Nam2, Seong Woon Roh2, and Jin-Woo Bae2*
Address 1Department of Microbiology, Pukyong National University, Pusan 608-737, Republic of Korea, 2Department of Life and Nanopharmaceutical Sciences and Department of Biology, Kyung Hee University, Seoul 130-701, Republic of Korea
Bibliography Journal of Microbiology, 48(2),213-222, 2010,
Key Words bacteriophage SP18, S. sonnei phage, T4-like phage, whole genome analysis, gene duplication
Abstract A novel bacteriophage that infects Shigella sonnei was isolated from the Gap River in Korea, and its phenotypic and genomic characteristics were investigated. The virus, called SP18, showed morphology characteristic of the family Myoviridae, and phylogenetic analysis of major capsid gene (gp23) sequences classified it as a T4-like phage. Based on host spectrum analysis, it is lytic to S. sonnei, but not to Shigella flexneri, Shigella boydii or members of the genera Escherichia and Salmonella. Pyrosequencing of the SP18 bacteriophage genome revealed a 170-kb length sequence. In total, 286 ORFs and 3 tRNA genes were identified, and 259 ORFs showed similarity (BLASTP e-value<0.001) to genes of other bacteriophages. The results from comparative genomic analysis indicated that the enterophage JS98, isolated from human stool, is the closest relative of SP18. Based on phylogenetic analysis of gp23 protein-coding sequences, dot plot comparison and BLASTP analysis of genomes, SP18 and JS98 appear to be closely related to T4-even phages. However, several insertions, deletions, and duplications indicate differences between SP18 and JS98. Comparison of duplicated gp24 genes and the soc gene showed that duplication events are responsible for the differentiation and evolution of T4-like bacteriophages.