First complete genome sequence of Staphylococcus xylosus, a meat starter culture and a host to propagate Staphylococcus aureus phages

Staphylococcus xylosus is a bacterial species used in meat fermentation and a commensal microorganism found on animals. We present the first complete circular genome from this species. The genome is composed of 2,757,557 bp, with a GC content of 32.9%, and contains 2,514 genes and 79 structural RNAs

Author Correction: Convalescent plasma for hospitalized patients with COVID-19: an open-label, randomized controlled trial (Nature Medicine, (2021), 27, 11, (2012-2024), 10.1038/s41591-021-01488-2)

In the version of this Article initially published, there was an omission in the member list for the CONCOR-1 Study Group. Valérie Arsenault (Héma-Québec, Montreal, Quebec, Canada) has now been included in the CONCOR-1 Study Group in the online version of the article

Complete genome sequence of Brevibacterium linens SMQ-1335

Brevibacterium linens is one of the main bacteria found in the smear of surface-ripened cheeses. The genome of the industrial strain SMQ-1335 was sequenced using PacBio. It has 4,209,935 bp, a 62.6% GC content, 3,848 open reading frames, and 61 structural RNAs. A new type I restriction-modification system was identified

Improving the Safety of <i>Staphylococcus aureus</i> Polyvalent Phages by Their Production on a <i>Staphylococcus xylosus</i> Strain

<div><p>Team1 (vB_SauM_Team1) is a polyvalent staphylococcal phage belonging to the <i>Myoviridae</i> family. Phage Team1 was propagated on a <i>Staphylococcus aureus</i> strain and a non-pathogenic <i>Staphylococcus xylosus</i> strain used in industrial meat fermentation. The two Team1 preparations were compared with respect to their microbiological and genomic properties. The burst sizes, latent periods, and host ranges of the two derivatives were identical as were their genome sequences. Phage Team1 has 140,903 bp of double stranded DNA encoding for 217 open reading frames and 4 tRNAs. Comparative genomic analysis revealed similarities to staphylococcal phages ISP (97%) and G1 (97%). The host range of Team1 was compared to the well-known polyvalent staphylococcal phages phi812 and K using a panel of 57 <i>S. aureus</i> strains collected from various sources. These bacterial strains were found to represent 18 sequence types (MLST) and 14 clonal complexes (eBURST). Altogether, the three phages propagated on <i>S. xylosus</i> lysed 52 out of 57 distinct strains of <i>S. aureus</i>. The identification of phage-insensitive strains underlines the importance of designing phage cocktails with broadly varying and overlapping host ranges. Taken altogether, our study suggests that some staphylococcal phages can be propagated on food-grade bacteria for biocontrol and safety purposes.</p></div

Host range of phages Team1, phi812, and K propagated on <i>S. aureus</i> SA812 and on <i>S. xylosus</i> SMQ-121.

<p>The results are expressed as EOP values. Bold characters indicate host strain.</p><p>0 indicates that no plaque was observed with high titer phage preparations.</p

Genotyping of the 57 <i>S. aureus</i> strains used in this study.

<p>Genotyping of the 57 <i>S. aureus</i> strains used in this study.</p

Electron micrograph of phage Team1.

<p>The bar scale  = 50 nm.</p

Codon usage of <i>S. aureus</i> JH1 and phages G1 and ISP for the amino acids encoded by the Team1 tRNAs (in bold).

<p>Codon usage of <i>S. aureus</i> JH1 and phages G1 and ISP for the amino acids encoded by the Team1 tRNAs (in bold).</p

One-step growth curves of both Team1-SA812 (▴) and Team1-SMQ121 (×).

<p>Error bars indicate the standard deviation for three trials. The first phage count (time zero) occurred approximately 10 min after adding the phage to the cells <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0102600#pone.0102600-Moineau1" target="_blank">[33]</a>.</p