The contribution of genes required for anaerobic respiration to the virulence of Salmonella enterica serovar Gallinarum for chickens

Abstract

Salmonella enterica serovar Gallinarum (SG) is an intracellular pathogen of chickens. To survive, to invade and to multiply in the intestinal tract and intracellularly it depends on its ability to produce energy in anaerobic conditions. The fumarate reductase (frdABCD), dimethyl sulfoxide (DMSO)-trimethylamine N-oxide (TMAO) reductase (dmsABC), and nitrate reductase (narGHIJ) operons in Salmonella Typhimurium (STM) encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. In this study mortality rates of chickens challenged with mutants of Salmonella Gallinarum, which were defective in utilising anaerobic electron acceptors, were assessed in comparison to group of bird challenged with wild strain. The greatest degree of attenuation was observed with mutations affecting nitrate reductase (napA, narG) with additional attenuations induced by a mutation affecting fumarate reductase (frdA) and a double mutant (dmsA torC) affecting DMSO and TMAO reductase.

Effects of colonization-associated gene yqiC on global transcriptome, cellular respiration, and oxidative stress in Salmonella Typhimurium

“…The napA mutant of S . Typhimurium exhibited a considerable growth defect in the low-nitrate colonic lumen of mice [ 48 ]; by contrast, the highest mortality rates of chickens challenged with mutants of S. gallinarum were associated with mutations in napA and narG , and additional attenuations were induced by a mutation in frdA and double mutations in dmsA and torC [ 49 ]. The findings are consistent with our emapplot network of downregulation in napA , dmsA , torC , and narG after the mutation in yqiC that is associated with colonization and ETCs.…”

Radiation-Inactivated S. gallinarum Vaccine Provides a High Protective Immune Response by Activating Both Humoral and Cellular Immunity

“…An inactivated vaccine can be considered as a safer alternative to SG 9R. However, several reports have shown that inactivated SG vaccines are not sufficient to provide protection against salmonellosis and less cross-protective against other Salmonella species, such as Salmonella Pullorum (SP) or Salmonella Enteritidis (SE) because of the low cell-mediated immune response (11,12). Of the several inactivation methods available for vaccine development, inactivation by irradiation has been reported to enhance the induction of cell-mediated immunity for bacterial and viral vaccines (13,14).…”

Microbiota-derived aspartate drives pathogenic Enterobacteriaceae expansion in the inflamed gut

“…Pathogenic Enterobacteriaceae have evolved to use fumarate reductase, encoded by frdABCD genes, to grow under anaerobic conditions in vitro and in vivo (Iverson et al, 1999; Jones et al, 2007; Mercado-Lubo et al, 2008; Paiva et al, 2009). Interestingly, the S. Tm and pks + E. coli SP15 genomes encode the aspA gene (aspartate ammonia-lyase), which enable the conversion of the amino acid aspartate into fumarate (Nguyen et al, 2020; Nógrády et al, 2003) ( Fig.…”

“…The S. Tm and E. coli genomes encode an aspartate-ammonia lyase ( aspA ) which enables the conversion of the amino acid aspartate into fumarate, an alternative electron acceptor (Falzone et al, 1988). S. Tm predominantly uses the fumarate reductase encoded by frdABCD genes under anaerobic or hypoxic conditions for expansion through fumarate respiration in the host gut during early infection (Arguello et al, 2010; Jones et al, 2007; Mercado-Lubo et al, 2008; Paiva et al, 2009). However, the major source of fumarate during later stages of S. Tm intestinal infection, and whether aspartate-dependent fumarate respiration supports microbiota outgrowth by pathogenic Enterobacteriaceae in the inflamed gut remains unclear.…”