Characterization of Genomic Diversity In Bacteriophages InfectingRhodococcus

Abstract

AbstractBacteriophages are globally ubiquitous viruses that infect bacteria. With nearly 4,000 sequenced genomes of phages infecting the phylum Actinobacteria available, genomic analyses of these actinobacteriophage genomes has been instrumental in uncovering a diverse genomic landscape often characterized by genome mosaicism. Here, we describe the genomic characterization of 57 sequenced phages capable of infecting the genusRhodococcus.These phages were previously isolated at multiple institutions by students in the SEA-PHAGES program using four different species ofRhodococcus.MostRhodococcusphages have been grouped into 4 clusters based on their genomic similarities; 13 phages are singletons too genetically distinct for clustering. These clusters and singletons containSiphoviridaeandMyoviridaephages, and most contain integrase and repressor genes indicative of a potential lysogenic life cycle. The genome size of these phages varies from 14,270 bp to 142,586 bp and their G+C% content ranges from 41.2–68.4%, while that of theirRhodococcushosts typically exceeds 60%. Through comparative genomic analyses, it was revealed that theseRhodococcusphages display high intracluster similarity but low intercluster similarity, despite their shared ability to infect the same host genus. Additionally, theseRhodococcusphages share similarities with phages that infect other Actinobacterial hosts such asGordonia, StreptomycesandArthrobacter.