LAUSR

This report presents the characterization of the first virulent phages infecting Brevibacterium aurantiacum, a bacterial species used during the manufacture of surface-ripened cheeses. These phages were also responsible for flavor and color defects in surface-ripened cheeses. Sixteen phages (out of sixty-two isolates) were selected for genome sequencing and comparative analyses. These cos-type phages with a long non-contractile tail currently belong to the Siphoviridae family (Caudovirales order). Their genome sizes vary from 35,637 bp to 36,825 bp and, similar to their host, have a high GC-content (~61%). Genes encoding for an immunity repressor, an excisionase and a truncated integrase were found, suggesting that these virulent phages may be derived from a prophage. Their genomic organization is highly conserved, with most of the diversity coming from the presence of long (198-bp) DNA tandem repeats (TR) within an orf coding for a protein of unknown function. We categorized these phages into seven genomic groups according to their number of TR, which ranged from two to eight. Moreover, we showed that TRs are widespread in phage genomes, found in more than 85% of the genomes available in public databases. This article is protected by copyright. All rights reserved.