The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection

Casper Schroll, Kaisong Huang, Shahana Ahmed, Bodil M. Kristensen, Susanne Elisabeth Pors, Lotte Jelsbak, Sebastien Lemire, Line E. Thomsen, Jens Peter Christensen, Peter R. Jensen, John E. Olsen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

Salmonella Pathogenicity Islands 19 (SPI19) encodes a type VI secretion system (T6SS). SPI19 is only present in few serovars of S. enterica, including the host-adapted serovar S. Dublin and the host-specific serovar S. Gallinarum. The role of the SPI19 encoded T6SS in virulence in these serovar is not fully understood. Here we show that during infection of mice, a SPI19/T6SS deleted strain of S. Dublin 2229 was less virulent than the wild type strain after oral challenge, but not after IP challenge. The mutant strain also competed significantly poorer than the wild type strain when co-cultured with strains of E. coli, suggesting that this T6SS plays a role in pathogenicity by killing competing bacteria in the intestine. No significant difference was found between wild type S. Gallinarum G9 and its ΔSPI19/T6SS mutant in infection, whether chicken were challenged orally or by the IP route, and the S. Gallinarum G9 ΔSPI19/T6SS strain competed equally well as the wild type strain against strains of E. coli. However, contrary to what was observed with S. Dublin, the wild type G9 strains was significantly more cytotoxic to monocyte derived primary macrophages from hens than the mutant, suggesting that SPI19/T6SS in S. Gallinarum mediates killing of eukaryotic cells. The lack of significant importance of SPI19/T6SS after oral and systemic challenge of chicken was confirmed by knocking out SPI19 in a second strain, J91. Together the results suggest that the T6SS encoded from SPI19 have different roles in the two serovars and that it is a virulence-factor after oral challenge of mice in S. Dublin, while we cannot confirm previous results that SPI19/T6SS influence virulence significantly in S. Gallinarum.

Original languageEnglish
JournalVeterinary Microbiology
Volume230
Pages (from-to)23-31
Number of pages9
ISSN0378-1135
DOIs
Publication statusPublished - 2019

Keywords

  • Cytotoxicity
  • Dublin
  • Gallinarum
  • Oral infection
  • Salmonella
  • Systemic infection
  • T6SS

Cite this

Schroll, Casper ; Huang, Kaisong ; Ahmed, Shahana ; Kristensen, Bodil M. ; Pors, Susanne Elisabeth ; Jelsbak, Lotte ; Lemire, Sebastien ; Thomsen, Line E. ; Christensen, Jens Peter ; Jensen, Peter R. ; Olsen, John E. / The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection. In: Veterinary Microbiology. 2019 ; Vol. 230. pp. 23-31.
@article{3a479f0e66064c1e91a187fda94b0353,
title = "The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection",
abstract = "Salmonella Pathogenicity Islands 19 (SPI19) encodes a type VI secretion system (T6SS). SPI19 is only present in few serovars of S. enterica, including the host-adapted serovar S. Dublin and the host-specific serovar S. Gallinarum. The role of the SPI19 encoded T6SS in virulence in these serovar is not fully understood. Here we show that during infection of mice, a SPI19/T6SS deleted strain of S. Dublin 2229 was less virulent than the wild type strain after oral challenge, but not after IP challenge. The mutant strain also competed significantly poorer than the wild type strain when co-cultured with strains of E. coli, suggesting that this T6SS plays a role in pathogenicity by killing competing bacteria in the intestine. No significant difference was found between wild type S. Gallinarum G9 and its ΔSPI19/T6SS mutant in infection, whether chicken were challenged orally or by the IP route, and the S. Gallinarum G9 ΔSPI19/T6SS strain competed equally well as the wild type strain against strains of E. coli. However, contrary to what was observed with S. Dublin, the wild type G9 strains was significantly more cytotoxic to monocyte derived primary macrophages from hens than the mutant, suggesting that SPI19/T6SS in S. Gallinarum mediates killing of eukaryotic cells. The lack of significant importance of SPI19/T6SS after oral and systemic challenge of chicken was confirmed by knocking out SPI19 in a second strain, J91. Together the results suggest that the T6SS encoded from SPI19 have different roles in the two serovars and that it is a virulence-factor after oral challenge of mice in S. Dublin, while we cannot confirm previous results that SPI19/T6SS influence virulence significantly in S. Gallinarum.",
keywords = "Cytotoxicity, Dublin, Gallinarum, Oral infection, Salmonella, Systemic infection, T6SS",
author = "Casper Schroll and Kaisong Huang and Shahana Ahmed and Kristensen, {Bodil M.} and Pors, {Susanne Elisabeth} and Lotte Jelsbak and Sebastien Lemire and Thomsen, {Line E.} and Christensen, {Jens Peter} and Jensen, {Peter R.} and Olsen, {John E.}",
year = "2019",
doi = "10.1016/j.vetmic.2019.01.006",
language = "English",
volume = "230",
pages = "23--31",
journal = "Veterinary Microbiology",
issn = "0378-1135",
publisher = "Elsevier",

}

Schroll, C, Huang, K, Ahmed, S, Kristensen, BM, Pors, SE, Jelsbak, L, Lemire, S, Thomsen, LE, Christensen, JP, Jensen, PR & Olsen, JE 2019, 'The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection', Veterinary Microbiology, vol. 230, pp. 23-31. https://doi.org/10.1016/j.vetmic.2019.01.006

The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection. / Schroll, Casper; Huang, Kaisong; Ahmed, Shahana; Kristensen, Bodil M.; Pors, Susanne Elisabeth; Jelsbak, Lotte; Lemire, Sebastien; Thomsen, Line E.; Christensen, Jens Peter; Jensen, Peter R.; Olsen, John E.

In: Veterinary Microbiology, Vol. 230, 2019, p. 23-31.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - The SPI-19 encoded type-six secretion-systems (T6SS) of Salmonella enterica serovars Gallinarum and Dublin play different roles during infection

AU - Schroll, Casper

AU - Huang, Kaisong

AU - Ahmed, Shahana

AU - Kristensen, Bodil M.

AU - Pors, Susanne Elisabeth

AU - Jelsbak, Lotte

AU - Lemire, Sebastien

AU - Thomsen, Line E.

AU - Christensen, Jens Peter

AU - Jensen, Peter R.

AU - Olsen, John E.

PY - 2019

Y1 - 2019

N2 - Salmonella Pathogenicity Islands 19 (SPI19) encodes a type VI secretion system (T6SS). SPI19 is only present in few serovars of S. enterica, including the host-adapted serovar S. Dublin and the host-specific serovar S. Gallinarum. The role of the SPI19 encoded T6SS in virulence in these serovar is not fully understood. Here we show that during infection of mice, a SPI19/T6SS deleted strain of S. Dublin 2229 was less virulent than the wild type strain after oral challenge, but not after IP challenge. The mutant strain also competed significantly poorer than the wild type strain when co-cultured with strains of E. coli, suggesting that this T6SS plays a role in pathogenicity by killing competing bacteria in the intestine. No significant difference was found between wild type S. Gallinarum G9 and its ΔSPI19/T6SS mutant in infection, whether chicken were challenged orally or by the IP route, and the S. Gallinarum G9 ΔSPI19/T6SS strain competed equally well as the wild type strain against strains of E. coli. However, contrary to what was observed with S. Dublin, the wild type G9 strains was significantly more cytotoxic to monocyte derived primary macrophages from hens than the mutant, suggesting that SPI19/T6SS in S. Gallinarum mediates killing of eukaryotic cells. The lack of significant importance of SPI19/T6SS after oral and systemic challenge of chicken was confirmed by knocking out SPI19 in a second strain, J91. Together the results suggest that the T6SS encoded from SPI19 have different roles in the two serovars and that it is a virulence-factor after oral challenge of mice in S. Dublin, while we cannot confirm previous results that SPI19/T6SS influence virulence significantly in S. Gallinarum.

AB - Salmonella Pathogenicity Islands 19 (SPI19) encodes a type VI secretion system (T6SS). SPI19 is only present in few serovars of S. enterica, including the host-adapted serovar S. Dublin and the host-specific serovar S. Gallinarum. The role of the SPI19 encoded T6SS in virulence in these serovar is not fully understood. Here we show that during infection of mice, a SPI19/T6SS deleted strain of S. Dublin 2229 was less virulent than the wild type strain after oral challenge, but not after IP challenge. The mutant strain also competed significantly poorer than the wild type strain when co-cultured with strains of E. coli, suggesting that this T6SS plays a role in pathogenicity by killing competing bacteria in the intestine. No significant difference was found between wild type S. Gallinarum G9 and its ΔSPI19/T6SS mutant in infection, whether chicken were challenged orally or by the IP route, and the S. Gallinarum G9 ΔSPI19/T6SS strain competed equally well as the wild type strain against strains of E. coli. However, contrary to what was observed with S. Dublin, the wild type G9 strains was significantly more cytotoxic to monocyte derived primary macrophages from hens than the mutant, suggesting that SPI19/T6SS in S. Gallinarum mediates killing of eukaryotic cells. The lack of significant importance of SPI19/T6SS after oral and systemic challenge of chicken was confirmed by knocking out SPI19 in a second strain, J91. Together the results suggest that the T6SS encoded from SPI19 have different roles in the two serovars and that it is a virulence-factor after oral challenge of mice in S. Dublin, while we cannot confirm previous results that SPI19/T6SS influence virulence significantly in S. Gallinarum.

KW - Cytotoxicity

KW - Dublin

KW - Gallinarum

KW - Oral infection

KW - Salmonella

KW - Systemic infection

KW - T6SS

U2 - 10.1016/j.vetmic.2019.01.006

DO - 10.1016/j.vetmic.2019.01.006

M3 - Journal article

VL - 230

SP - 23

EP - 31

JO - Veterinary Microbiology

JF - Veterinary Microbiology

SN - 0378-1135

ER -