The characteristics and genome analysis of the novel Y. pestis phage JC221.

The pathogen of plague is Yersinia pestis (Y. pestis), one of the deadliest pathogens in the world and belonging to the family Enterobacteriaceae. In this work, the biological characteristics and complete genome sequence analysis of a novel lytic Y. pestis-specific phage JC221 isolated from Yunnan Province, China, was studied. JC221 belongs to the Myoviridae family and has a regular icosahedral head and a long contractile tail. The double-stranded DNA genome of JC221 contains 174,931 bp, and the G + C content is 41.23 %. There are 274 predicted genes, of which only 103 hits of genes or gene products are found in database searches, and there are no known virulence-related or antibiotic resistance genes. The genome sequence of JC221 showed <80 % identity to other phages, and evolutionary analysis revealed that bacteriophage JC221 belongs to the Yersinia phage cluster. Furthermore, the bacteriophage could completely lyse most of the tested Y. pestis strains (12/13) at 28 °C and 37 °C, and some Shigella strains could be lysed at 37°C. Morphological and genomic analysis indicated that JC221 is a new Y. pestis phage and a new member of the Tequatrovirus phages. The novel Y. pestis phage JC221 has important reference value for the study of environmental microecology and epidemiology of plague foci.