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Shigella is one of the most important waterborne and foodborne pathogens around the world. Emergence of antibiotic-resistant Shigella has made the development of alternatives to conventional antibiotics necessary. In this study, a virulent Myoviridae bacteriophage, pSs-1 was isolated from environmental water in South Korea and showed infectivity to S. flexneri as well as S. sonnei strains. One-step growth analysis showed that pSs-1 has a short latent period (25 min) and a large burst size (97 PFU/cell). According to the genomic analysis, pSs-1 contains 164,999 bp of genome with a G + C content of 35.54% and it is considered as a member of the T4-like bacteriophage group. These results showed that pSs-1 may have potential as a biocontrol agent instead of conventional antibiotics for shigellosis.

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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.

pAh6-C is a virulent bacteriophage (phage), isolated from a river in Korea, that infects a multiple-antibiotic-resistant A. hydrophila strain, JUNAH. The double-stranded DNA genome of pAh6-C is composed of 53,744 bp with a G + C content of 52.83 %. The genome encodes 86 putative ORFs, four putative promoters, and seven transcriptional terminator regions. Genome sequence analysis of pAh6-C and comparative analysis with the homologous Shewanella phage Spp001 revealed that there is a high degree of similarity between pAh6-C and Spp001 in 50 of the 86 ORFs of pAh6-C. The results of this investigation indicate that pAh6-C is closely related to Spp001, especially in the genes coding for proteins involved in DNA metabolism.