Birds Kept in the German Zoo “Tierpark Berlin” Are a Common Source for Polyvalent Yersinia pseudotuberculosis Phages

Abstract

Yersinia pseudotuberculosis is an important animal pathogen, particularly for birds, rodents, and monkeys, which is also able to infect humans. Indeed, an increasing number of reports have been published on zoo animals that were killed by this species. One option to treat diseased animals is the application of strictly lytic (virulent) phages. However, thus far relatively few phages infecting Y. pseudotuberculosis have been isolated and characterized. To determine the prevalence of Y. pseudotuberculosis phages in zoo animals, fecal samples of birds and some primates, maras, and peccaries kept in the Tierpark Berlin were analyzed. Seventeen out of 74 samples taken in 2013 and 2017 contained virulent phages. The isolated phages were analyzed in detail and could be allocated to three groups. The first group is composed of 10 T4-like phages (PYps2T taxon group: Myoviridae; Tevenvirinae; Tequatrovirus), the second group (PYps23T taxon group: Chaseviridae; Carltongylesvirus; Escherichia virus ST32) consists of five phages encoding a podovirus-like RNA polymerase that is related to an uncommon genus of myoviruses (e.g., Escherichia coli phage phiEcoM-GJ1), while the third group is comprised of two podoviruses (PYps50T taxon group: Autographiviridae; Studiervirinae; Berlinvirus) which are closely related to T7. The host range of the isolated phages differed significantly. Between 5.5 and 86.7% of 128 Y. pseudotuberculosis strains belonging to 20 serotypes were lysed by each phage. All phages were additionally able to lyse Y. enterocolitica B4/O:3 strains, when incubated at 37°C. Some phages also infected Y. pestis strains and even strains belonging to other genera of Enterobacteriaceae. A cocktail containing two of these phages would be able to lyse almost 93% of the tested Y. pseudotuberculosis strains. The study indicates that Y. pseudotuberculosis phages exhibiting a broad-host range can be isolated quite easily from zoo animals, particularly birds.

Biological and genomic characterization of three psychrophilic Y. enterocolitica phages

“…CsCl-purified phages were investigated by TEM using the negative staining procedure with uranyl acetate (VWR International, Darmstadt, Germany) as described by Jäckel et al (2017) . Specimens were examined by TEM using a JEM-1010 (JEOL, Tokyo, Japan) at an 80 kV acceleration voltage ( Hammerl et al, 2021a ).…”

“…All software tools were used with default settings. Basic sequence analysis was conducted using DS Gene (version 2.5; Accelrys Inc., San Diego, CA, USA) ( Hammerl et al, 2021a ).…”

Pathogenic Bacteria in Free-Living Birds, and Its Public Health Significance

“…The Yersinia genus is comprised of 28 distinct species, of which 3 have the potential to cause illness in humans. Yersinia pestis is the culprit behind the plague, while Yersinia pseudotuberculosis and Y. enterocolitica are enteropathogenic species that can lead to yersiniosis [ 105 , 106 ]. It has been discovered that both Y. pseudotuberculosis and Y. enterocolitica are capable of causing disease in both humans and animals [ 107 ].…”

Phage vB_YenS_P400, a Novel Virulent Siphovirus of Yersinia enterocolitica Isolated from Deer

“…CsCl-purified phages were investigated by TEM using the negative staining procedure with uranyl acetate (VWR International, Darmstadt, Germany) as previously described [22]. Specimens were examined by TEM using a JEM-1010 (JEOL, Tokyo, Japan) at an 80 kV acceleration voltage [24].…”

“…However, it certainly cannot be ruled out that in the gut bacteria other than Yersinia, which were not tested in this study, may be infected by vB_YenS_P400. Some Y. pseudotuberculosis phages isolated from fecal samples of birds and mammals were able to lyse various genera of Enterobacteriaceae [24]. * A vB_YenS_P400 titer of 1-2 × 10 2 pfu/mL was used for the determination of the burst size.…”