Salmonella enterica serovar Choleraesuis derivatives harbouring deletions in rpoS and phoP regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively.

Imagen de Alberto Tierrez Martínez
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TítuloSalmonella enterica serovar Choleraesuis derivatives harbouring deletions in rpoS and phoP regulatory genes are attenuated in pigs, and survive and multiply in porcine intestinal macrophages and fibroblasts, respectively.
Publication TypeJournal Article
Year of Publication2008
AutoresDomínguez-Bernal, G, Tierrez, A, Bartolomé, A, Martínez-Pulgarín, S, Salguero, FJ, Antonio Orden, J, de la Fuente, R
JournalVet Microbiol
Volume130
Issue3-4
Pagination298-311
Date Published2008 Aug 25
ISSN0378-1135
Palabras claveAnimals, Bacterial Proteins, Cells, Cultured, Fibroblasts, Gene Deletion, Gene Expression Regulation, Bacterial, Intestines, Macrophages, Mice, Mice, Inbred BALB C, Salmonella enterica, Salmonella Infections, Animal, Sigma Factor, Swine, Swine Diseases, Virulence
Abstract

Live attenuated Salmonella enterica strains have been extensively studied as potential vectors for the oral delivery of heterologous antigens. Due to its ability to target immune cells, its specific mechanism for crossing the intestinal barrier, and its swine-restricted tropism, S. enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) has attracted a great deal of interest for the production of bacterial-based oral carriers specifically adapted to swine. In this study, two mutants of S. Choleraesuis were constructed and their attenuation and intracellular fate analysed with the purpose of engineering new attenuated live strains with improved properties as oral vaccine carriers. Those strains harboured a specific deletion either within the phoP or rpoS genes, which encode virulence-related regulators in S. Typhimurium. In comparison to the wild-type parental S. Choleraesuis, the mutant strains, especially DeltaphoP, were extremely low in virulence in the murine model and in the natural host, the pig. Moreover, when compared with a commercial live vaccine strain, SC-54, the two mutants showed a higher level of attenuation in mice and DeltaphoP also in pigs. In addition, DeltarpoS and DeltaphoP presented a proliferation and survival phenotype within swine intestinal primary fibroblast and macrophage cell cultures, respectively. Collectively, the present results indicate that the DeltarpoS and DeltaphoP strains of S. Choleraesuis gather adequate features to be potential candidates for vaccine vectors for the specific delivery of heterologous antigens adapted to pigs.

DOI10.1016/j.vetmic.2008.01.008
Alternate JournalVet. Microbiol.
PubMed ID18313237