Complete genome sequence analysis of a lytic Shigella flexneri vB_SflS-ISF001 bacteriophage

Abstract

Shigellosis is one of the most important acute enteric infections caused by different species of Shigella, such as Shigella flexneri. Despite the use of antibiotic therapy to reduce disease duration, this approach is becoming less effective due to the emergence of antibiotic resistance among Shigella spp. Bacteriophages have been introduced as an alternative for controlling shigellosis. However, the bacteriophages must be without any lysogenic or virulence factors, toxin coding, or antibiotic-resistant genes. In this study, the whole genome sequence of vB_SflS-ISF001, a virulent Siphoviridae bacteriophage specific for Shigella flexneri, was obtained, and a comparative genomic analysis was carried out to identify its properties and safety. vB_SflS-ISF001 genomic DNA was measured at 50,552 bp with 78 deduced open reading frames (ORFs), with 24 ORFs (30.77%) sharing similarities with proteins from the genomes of homologous phages that had been reported earlier. Genetic analysis classifies it under the genus T1virus of the subfamily Tunavirinae. Moreover, comparative genomic analysis revealed no undesirable genes in the genome of vB_SflS-ISF001, such as antibiotic resistance, virulence, lysogeny, or toxin-coding genes. The results of this investigation indicate that vB_SflS-ISF001 is a new species, and confirm its safety for the biocontrol of S. flexneri.