Genome-Based Taxonomic Classification of Listeria phage and Diversity Analysis of Major Capsid Protein, Receptor-Binding Protein and Endolysin

Jinni ChenHao ZhouLingyun LiuPan MaoLingling LiXuefang XuJi PuJing YangHui SunXia LuoYan Wang^*Changyun Ye^*

• National Institute for Communicable Disease Control and Prevention (China CDC), Beijing, China

Listeria monocytogenes (Lm) poses a significant risk to food safety due to its adaptability and pathogenicity, while Listeria phages show great promise as biocontrol agents. This study comprehensively analysed 97 complete genomes of Listeria phages from 14 countries across four continents, including 16 newly isolated phages with phenotype characteristics. The phages were grouped into nine genomic clusters, which clearly distinguished between virulent and temperate lifestyles. Temperate phages demonstrate greater genomic diversity than virulent ones. Cluster 1 phages are assigned to the genus Pecentumvirus and appear to have an ecological advantage based on genomic characteristics, exhibiting a broad geographical distribution with diverse sources. Evolutionary analyses classified the major capsid protein (MCP), receptor-binding protein (RBP), and endolysin of Listeria phages into nine, seven, and eight distinct types, respectively. These three proteins showed high levels of conservation within the virulent clusters, but significant diversity within the temperate clusters. Notably, RBP of types R1, R2, R4, and R6 are associated with broad host ranges and distributed across Clusters 1, 2, 7, and 8 phages. Cluster 3 phages lacked identifiable RBP sequences, suggesting the absence of canonical domains detectable by standard prediction tools. These findings refine the classification of Listeria phages and significantly advance the current understanding of the taxonomy, genomic diversity, and global distribution of Listeria phages.