Description of Erysipelothrix piscisicarius sp. nov., an emergent fish pathogen, and assessment of virulence using a tiger barb (Puntigrus tetrazona) infection model

Abstract

A recently described emergent disease of ornamental fish has been associated with an Erysipelothrix species positive for the surface protective antigen (spa) C gene. Whole genome sequencing was performed on five spaC Erysipelothrix isolates from diseased ornamental fish. In addition, these spaC Erysipelothrix isolates were compared to spaA-, spaB- and other spaC-positive Erysipelothrix species isolated from terrestrial and marine mammals, birds and fish using multi-locus sequence analysis (MLSA). The genomes of fish pathogenic spaC isolates were genetically distinct from Erysipelothrix rhusiopathiae , sharing 86.61–86.94 % average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values of 31.6–32.2 %, but 99.01–99.11 % ANI and 90.8–91.9 % dDDH values with the uncharacterized spaC-positive Erysipelothrix sp. strain 2 isolated from swine. The findings indicate the spaC-positive fish and swine isolates are conspecific and represent a previously unrecognized taxon. While phylogenies inferred from MLSA sequences confirm this conclusion, slight genetic differences between the spaC fish isolates and swine strain 2 were indicated. Bath immersion challenge trials were conducted using tiger barbs (Puntigrus tetrazona) exposed by immersion to 107 c.f.u. ml−1 of three fish pathogenic spaC Erysipelothrix species, and three spaA and two spaB E. rhusiopathiae isolates as a model of infection. Thirty days post-challenge, cumulative mean percentage survival was 37 % for the spaA, 100 % for the spaB and 13 % for the spaC isolates, revealing differences in virulence among the various spa genotypes in fish. Genetic findings and observed differences in virulence demonstrate the fish pathogenic spaC isolates represent a novel species, for which the name Erysipelothrix piscisicarius sp. nov. is proposed. The type strain is E. piscisicarius 15TAL0474T (=NRRL B-65533T=ATCC-TSD-175T=DSM 110099T).

An invasive infection with an unusual spaB-possessing Erysipelothrix rhusiopathiae in a human

“…nov., which have often been isolated from food-producing animals and ornamental fish [19], respectively, can cause substantial illness in humans. The serovars reported in these species are serovars 3,7,10,14,15,16,20,22 and 23 for E. tonsillarum [20], and serovars 5, 9, 10 and 18 for E. piscisicarius sp. nov [11,19,20].…”

“…The Spa protein has been antigenically divided into SpaA, SpaB and SpaC, and reported to be associated with the serovars of Erysipelothrix strains: E. rhusiopathiae serovars 1a, 1b, 2, 5, 8, 9, 12, 15-17 and 23 possess SpaA; E. rhusiopathiae serovars 4, 6, 11, 19 and 21 possess SpaB [6]; and a different species (Erysipelothrix piscisicarius sp. nov.) possesses SpaC [7]. Furthermore, it has been reported that E. rhusiopathiae clade 1, which is common in marine animals, possesses the spaB gene, whereas E. rhusiopathiae clades 2 and 3, which are common in pig and poultry, possess the spaA gene [4].…”

“…rhusiopathiae serovars 4, 6, 11, 19 and 21 possess SpaB [6]; and a different species ( Erysipelothrix piscisicarius sp. nov.) possesses SpaC [7]. Furthermore, it has been reported that E.…”

Erysipelothrix Spp.: Past, Present, and Future Directions in Vaccine Research

“…can be divided into eight different species: Erysipelothrix rhusiopathiae (2, 3), Erysipelothrix tonsillarum (4), Erysipelothrix species 1, Erysipelothrix species 2, and Erysipelothrix species 3 (5), Erysipelothrix inopinata (6), Erysipelothrix larvae (7) and Erysipelothrix piscisicarius sp. nov. (8). Isolates associated with these species were identified in mammals, birds and fish (E. rhusiopathiae, E. tonsillarum and E. species 1, 2, and 3; E. piscisicarius), a vegetable peptone broth (E. inopinata) or insects (E. larvae).…”

Development of a Multiplex PCR-Based Assay for Rapid Serotyping of Erysipelothrix Species

“…The genus Erysipelothrix is composed of at least five species, E. rhusiopathiae, Erysipelothrix tonsillarum (2), Erysipelothrix inopinata (3), Erysipelothrix larvae (4), and Erysipelothrix piscisicarius sp. nov. (5), the last of which is pathogenic to fish and has been recently proposed as a new member of the genus. Furthermore, the existence of three other species, which are unnamed and tentatively referred to as Erysipelothrix sp.…”