Complete Genome Sequence of Stenotrophomonas maltophilia Myophage Marzo

ABSTRACT Stenotrophomonas maltophilia is a Gram-negative opportunistic bacterium that is increasingly being associated with infections. Here, we report the complete genome of the S. maltophilia myophage Marzo, with a 159,384-bp genome encoding 268 proteins, 23 tRNAs, and 1 transfer-messenger RNA. Marzo is closely related to S. maltophilia phages IME-SM1 and Mendera.

S tenotrophomonas maltophilia is found in aqueous habitats, including plant rhizospheres and animals, and is an opportunistic Gram-negative bacterium that can cause infections in tissues ranging from the skin to the heart in immunocompromised individuals (1). We are interested in studying S. maltophilia phage genomes in the interest of exploring potential therapeutic treatment options.
Phage Marzo was determined to be a myophage via negative staining with 2% (wt/vol) uranyl acetate and imaging by transmission electron microscopy (TEM) at the Texas A&M University Microscopy and Imaging Center (Fig. 1). The completed 159,384-bp myophage Marzo genome has 24-fold sequencing coverage and a G1C content of 54%. PhageTerm was unable to predict phage termini from the raw sequencing reads, but due to its similarities in terms of morphology and genome size to the canonical phage T4, Marzo likely uses headful packaging. Twenty-three tRNA genes, 1 tmRNA gene, and 268 protein-coding genes were found, with a coding density of 93%. The tRNA genes were found in two clusters, one with 3 tRNAs and the tmRNA and the other with 20 tRNAs. The Marzo tmRNA was highly similar to the SsrA Betaproteobacter-class tmRNA of S. maltophilia, as determined by sequence analysis at RNAcentral (21). Comparative genomics revealed that Marzo has $92% nucleotide identity to other S. maltophilia myophages, namely, IME-SM1 (GenBank accession number KR560069), YB07 (GenBank accession number NC_048755), and Mendera (GenBank accession number NC_048804). Some structural genes could be identified, encoding tail completion scaffold, portal, major capsid, baseplate wedge, and tail tube proteins. In addition, although no holin or endolysin genes could be identified, two spanin gene pairs were identified, one of the overlapping class and the other of the embedded class.
Data availability. The Marzo genome was deposited in GenBank with accession number MZ326868. The associated BioProject, SRA, and BioSample accession numbers are PRJNA222858, SRR14095257, and SAMN18509700, respectively.

ACKNOWLEDGMENTS
Funding was provided by the National Science Foundation (awards EF-0949351 and DBI-1565146), the CPT (an initial university multidisciplinary research initiative supported by Texas A&M University and Texas AgriLife), and the Department of Biochemistry and Biophysics (https://cpt.tamu.edu).
We are grateful for the advice and support of the CPT members, especially Carlos Gonzalez, who provided the Stenotrophomonas strain.
This announcement was prepared in partial fulfillment of the requirements for BICH464 Phage Genomics, an undergraduate course at Texas A&M University.