METHODS AND RESULTS: Transmission electron microscopy revealed phage pPM_01 to be a siphovirus (the first reported virus to infect P. mirabilis), with its complete genome sequence successfully determined. The genome was sequenced using Illumina technology and the reads obtained were assembled using CLC Genomic Workbench v.7.0.3. The whole genome contains a total of 58,546 bp of linear double-stranded DNA with a G+C content of 46.9%. Seventy putative genes were identified and annotated using various bioinformatics tools including RAST, Geneious v.R7, National Center for Biotechnology Information (NCBI) BLAST, and tRNAscan-SE-v1.3 Search. Functional clusters of related potential genes were defined (structural, lytic, packaging, replication, modification, and modulatory). The whole genome sequence showed a low similarity to known phages (i.e., Enterobacter phage Enc34 and Enterobacteria phage Chi). Host range determination and SDS-PAGE analysis were also performed.
CONCLUSIONS: The inability to lysogenize a host, the absence of endotoxin genes in the annotated genome, and the lytic behavior suggest phage pPM_01 as a possible safe biological candidate to control P. mirabilis infection.