Isolation and Comparative Genomic Analysis of T1-Like Shigella Bacteriophage pSf-2

The increasing prevalence of antibiotic-resistant Shigella sp. emphasizes that alternatives to conventional antibiotics are needed. Siphoviridae bacteriophage (phage), pSf-2, infecting S. flexneri ATCC(®) 12022 was isolated from Geolpocheon stream in Korea. Morphological analysis by transmission electron microscopy revealed that pSf-2 has a head of about 57 ± 4 nm in diameter with a long tail of 136 ± 3 nm in length and 15 ± 2 nm in width. One-step growth analysis revealed that pSf-2 has latent period of 30 min and burst size of 16 PFU/infected cell. The DNA genome of pSf-2 is composed of 50,109 bp with a G+C content of 45.44 %. The genome encodes 83 putative ORFs, 19 putative promoters, and 23 transcriptional terminator regions. Genome sequence analysis of pSf-2 and comparative analysis with the homologous T1-like Shigella phages, Shfl1 and pSf-1, revealed that pSf-2 is a novel T1-like Shigella phage. These results showed that pSf-2 might have a high potential as a biocontrol agent to control shigellosis. Also, the genomic information may lead to further understanding of phage biodiversity, especially T1-like phages.