AUTHOR=Liu Wenhua , Han Letian , Song Peng , Sun Huzhi , Zhang Can , Zou Ling , Cui Jiaqi , Pan Qiang , Ren Huiying 

TITLE=Complete genome sequencing of a Tequintavirus bacteriophage with a broad host range against Salmonella Abortus equi isolates from donkeys

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.938616

DOI=10.3389/fmicb.2022.938616

ISSN=1664-302X

ABSTRACT=<p>Salmonella enterica subspecies enterica serovar abortus equi (<italic>S. Abortus equi</italic>) is the most common cause of abortion in mares. It has recently been found to cause abortion in donkeys more frequently in China. A novel virulent bacteriophage vB_SabS_Sds2 (hereafter designated as Sds2) was isolated from the feces of donkeys using a <italic>S. Abortus equi</italic> strain as a host. Phage Sds2 had an isometric polyhedral head and an uncontracted long tail, belonging to the <italic>Tequintavirus</italic>, <italic>Markadamsvirinae</italic>, <italic>Demerecviridae</italic>, <italic>Caudovirales</italic>. The genome of phage Sds2 was 114,770 bp, with a GC content of 40.26%. The genome contained 160 open reading frames (ORFs), and no ORFs were associated with pathogenicity, drug resistance, or lysogenization by sequence analysis. Both genome annotation and phylogenetic analysis indicated that phage Sds2 was highly similar to T5-like bacteriophages. Phage Sds2 could lyse 100% (30/30) of <italic>S. Abortus equi</italic> strains, 25.3% (24/95) of other serotypes of <italic>Salmonella</italic> strains, and 27.6% (8/29) of <italic>Escherichia coli</italic> strains using the double-layer agar plate method. The <italic>in vitro</italic> test showed that phage Sds2 had high bactericidal activity against <italic>S. Abortus equi</italic> at a wide range of MOIs. The <italic>in vivo</italic> test indicated that phage Sds2 had an inhibitory effect on abortion in mice challenged with <italic>S. Abortus equi.</italic> In general, phage Sds2 is a novel lytic phage with a wide host range and has the potential to prevent abortion caused by <italic>S. Abortus equi.</italic></p>