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ORIGINAL RESEARCH article

Front. Vet. Sci.
Sec. Veterinary Infectious Diseases
Volume 11 - 2024 | doi: 10.3389/fvets.2024.1496684
This article is part of the Research Topic Bacteriophages, a weapon against animal bacterial pathogens and biofilms View all 3 articles

Characterization of a Salmonella abortus equi phage 4FS1 and its depolymerase

Provisionally accepted
Jianchao Zhao Jianchao Zhao Jiayu Wang Jiayu Wang Can Zhang Can Zhang Shouzhen Xu Shouzhen Xu Huiying Ren Huiying Ren Ling Zou Ling Zou Jing Ma Jing Ma Wenhua Liu Wenhua Liu *
  • Qingdao Agricultural University, Qingdao, China

The final, formatted version of the article will be published soon.

    The significant economic losses caused by S. abortus equi in donkey husbandry have increased interest in exploring the potential of phages and their enzymes as control strategies. A S. abortus equi phage, designated 4FS1, was isolated from sewage at a donkey farm. Transmission electron microscopy (TEM) revealed a typical icosahedral head and a long, non-contractile tail. It exhibited a short latent period of 20 minutes and a burst size of 160 plaque-forming units (PFU) per cell. It demonstrated a broad host range, infecting 36 out of 60 salmonella strains, with an optimal multiplicity of infection (MOI) of 0.01 for S. abortus equi S1. The phage titer remained stable at 10 9 PFU/mL between 37℃ and 50℃ and exceeded 10 8 PFU/mL at pH from 5.0 to 10.0. After one hour of UV exposure, the titer remained at 10 7 PFU/mL and showed no significant variation across NaCl concentrations from 2.5% to 15%. The genome of phage 4FS1 consists of a 42,485 bp linear double-stranded DNA molecule with a G+C content of 49.07%. Of the 56 predicted open reading frames (ORFs), 32 were functional annotated, with no virulence or drug resistance genes identified.ORF36 was predicted to encode a depolymerase responsible for endorhamnosidase activity.Recombinant expression of the Dpo36 protein in prokaryotes significantly reduced biofilm formation and removal. Combined with healthy donkey serum, Dpo36 inhibited bacterial growth in vitro and enhanced the survival rates of mice infected with S. abortus equi. These findings highlight the promising potential of phages and their depolymerases as novel therapeutic agents against S. abortus equi.

    Keywords: S. abortus equi, Phage 4FS1, Depolymerase, Biofilm, Polysaccharides

    Received: 15 Sep 2024; Accepted: 04 Nov 2024.

    Copyright: © 2024 Zhao, Wang, Zhang, Xu, Ren, Zou, Ma and Liu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Wenhua Liu, Qingdao Agricultural University, Qingdao, China

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