Isolation and Characterization of a Novel Salmonella Phage vB_SalP_TR2

Abstract

<i>Salmonella</i> is a widely distributed foodborne pathogen. The use of <i>Salmonella</i> phages as biocontrol agents has recently gained significant interest. Because the <i>Salmonella</i> genus has high diversity, efforts are necessary to identify lytic <i>Salmonella</i> phages focusing on different serovars. Here, five <i>Salmonella</i> phages were isolated from soil samples, and vB_SalP_TR2 was selected as a novel phage with high lytic potential against the host <i>Salmonella</i> serovar Albany, as well as other tested serovars, including Corvallis, Newport, Kottbus, and Istanbul. Morphological analyses demonstrated that phage vB_SalP_TR2 belongs to the <i>Podoviridae</i> family, with an icosahedral head (62 ± 0.5 nm in diameter and 60 ± 1 nm in length) and a short tail (35 ± 1 nm in length). The latent period and burst size of phage vB_SalP_TR2 was 15 min and 211 PFU/cell, respectively. It contained a linear dsDNA of 71,453 bp, and G + C content was 40.64%. Among 96 putative open reading frames detected, only 35 gene products were found in database searches, with no virulence or antibiotic resistance genes being identified. As a biological control agent, phage vB_SalP_TR2 exhibited a high temperature and pH tolerance. <i>In vitro</i>, it lysed most <i>S.</i> Albany after 24 h at 37°C with multiplicities of infection of 0.0001, 0.001, 0.01, 0.1, 1, 10, and 100. In food matrices (milk and chicken meat), treatment with phage vB_SalP_TR2 also reduced the number of <i>S.</i> Albany compared with that in controls. These findings highlighted phage vB_SalP_TR2 as a potential antibacterial agent for the control of <i>Salmonella</i> in food samples.