Yersinia enterocolitica-Specific Infection by Bacteriophages TG1 and ϕR1-RT Is Dependent on Temperature-Regulated Expression of the Phage Host Receptor OmpF

Abstract

Bacteriophages present huge potential both as a resource for developing novel tools for bacterial diagnostics and for use in phage therapy. This potential is also valid for bacteriophages specific for Yersinia enterocolitica. To increase our knowledge of Y. enterocolitica-specific phages, we characterized two novel yersiniophages. The genomes of the bacteriophages vB_YenM_TG1 (TG1) and vB_YenM_R1-RT (R1-RT), isolated from pig manure in Canada and from sewage in Finland, consist of linear double-stranded DNA of 162,101 and 168,809 bp, respectively. Their genomes comprise 262 putative coding sequences and 4 tRNA genes and share 91% overall nucleotide identity. Based on phylogenetic analyses of their whole-genome sequences and large terminase subunit protein sequences, a genus named Tg1virus within the family Myoviridae is proposed, with TG1 and R1-RT (R1RT in the ICTV database) as member species. These bacteriophages exhibit a host range restricted to Y. enterocolitica and display lytic activity against the epidemiologically significant serotypes O:3, O:5,27, and O:9 at and below 25°C. Adsorption analyses of lipopolysaccharide (LPS) and OmpF mutants demonstrate that these phages use both the LPS inner core heptosyl residues and the outer membrane protein OmpF as phage receptors. Based on RNA sequencing and quantitative proteomics, we also demonstrate that temperature-dependent infection is due to strong repression of OmpF at 37°C. In addition, R1-RT was shown to be able to enter into a pseudolysogenic state. Together, this work provides further insight into phage-host cell interactions by highlighting the importance of understanding underlying factors which may affect the abundance of phage host receptors on the cell surface. IMPORTANCEOnly a small number of bacteriophages infecting Y. enterocolitica, the predominant causative agent of yersiniosis, have been previously described. Here, two newly isolated Y. enterocolitica phages were studied in detail, with the aim of elucidating the host cell receptors required for infection. Our research further expands the repertoire of phages available for consideration as potential antimicrobial agents or as diagnostic tools for this important bacterial pathogen.Y ersinia enterocolitica, a facultative anaerobic, Gram-negative, nonsporulating, short bacillus isolated frequently from soil, water, animals, and foods, is an important zoonotic pathogen leading to human and animal enteric infection (1). The main animal reservoir for Y. enterocolitica is pigs, and pork-derived products are thought to be the main source of human infections, in addition to the drinking of contaminated water and blood transfusions (1, 2). Symptoms of yersiniosis may include diarrhea, terminal ileitis, mesenteric lymphadenitis, and septicemia (3). Among the species within the genus Yersinia, Y. enterocolitica is highly heterogeneous and is grouped into six phylogroups (4). The widely used bioserotype groups form the basis of the phylogroups such that phylogroup 1 contains the biotype 1A strains,...

The Yersinia Phage X1 Administered Orally Efficiently Protects a Murine Chronic Enteritis Model Against Yersinia enterocolitica Infection

“…To determine the host range of the phage, spot test and doublelayer agar plate methods were used as described previously (Leon-Velarde et al, 2016).…”

“…From 2000 to 2019, only several Y. enterocolitica bacteriophages have been reported (Leon-Velarde et al, 2016;Leskinen et al, 2016). Phage PY100 was administered orally in a murine model of Y. enterocolitica, unfortunately, the treatment using this phage with multiple applications and a high dose did not yield satisfying results (Skurnik and Strauch, 2006;Schwudke et al, 2008).…”

Bacteriophages reduce Yersinia enterocolitica contamination of food and kitchenware

“…A number of Yersinia-specific phages have been documented to date (Kiljunen et al, 2005a(Kiljunen et al, , 2005bLeon-Velarde et al, 2016;Pajunen et al, 2000Pajunen et al, , 2001Schwudke et al, 2008;Skurnik et al, 2012). Such phages have been isolated and characterized (Leon-Velarde et al, 2016;Salem et al, 2015) and phage application in meat at 4°C against Y. enterocolitica was studied (Orquera et al, 2012). However, application of phages on the surface of RTE food or kitchen utensils against Y. enterocolitica has not been studied.…”

“…Table 1 Bacterial strains used in this study and infectivity of the Yersinia phages fHe-Yen3-01, fHe-Yen9-01, fHe-Yen9-02, and fHe-Yen9-03. Although several phages able to infect Y. enterocolitica have been described, their study has focused only on physiological and/or genomic characterization (Kiljunen et al, 2005a(Kiljunen et al, , 2005bLeon-Velarde et al, 2016;Pajunen et al, 2000Pajunen et al, , 2001Schwudke et al, 2008;Skurnik et al, 2012). In the current work, we isolated and characterized a virulent Podoviridae phage, designated fHe-Yen3-01, and three virulent Myoviridae phages, fHe-Yen9-01, fHe-Yen9-02, and fHe-Yen9-03 from a Finnish sewage sample.…”

Yersinia Phages and Food Safety

“…Next are Yersinia phage ϕR1-RT and vB_YenM_TG1, which are closely related Myoviruses with a T4-like gene arrangement isolated in Finland and Canada, respectively [44]. Based on phylogenetic analyses of their whole genome sequences and large terminase subunit protein sequences, a genus named [44].…”