Correction for Blondel et al., The Type VI Secretion System Encoded in Salmonella Pathogenicity Island 19 Is Required for Salmonella enterica Serotype Gallinarum Survival within Infected Macrophages
| Autor: | Francisca Contreras, Bernardo I. Pinto, Carlos A. Santiviago, Inés Contreras, Carlos J. Blondel, Juan Cristobal Jimenez, Sergio A. Álvarez, David Pezoa, Lorenzo Eugenio Leiva |
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| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Serotype
Salmonella Veterinary medicine Time Factors Genomic Islands Cell Survival Virulence Factors Immunology medicine.disease_cause Microbiology Cell Line chemistry.chemical_compound Mice RNA polymerase medicine Animals Bacterial Secretion Systems Type VI secretion system Microbial Viability biology Macrophages Membrane Transport Proteins Salmonella enterica biology.organism_classification Virology Pathogenicity island Author Corrections Blot Infectious Diseases chemistry Parasitology Chickens Gene Deletion |
| Popis: | Salmonella enterica serotype Gallinarum is the causative agent of fowl typhoid, a disease characterized by high morbidity and mortality that causes major economic losses in poultry production. We have reported that S. Gallinarum harbors a type VI secretion system (T6SS) encoded in Salmonella pathogenicity island 19 (SPI-19) that is required for efficient colonization of chicks. In the present study, we aimed to characterize the SPI-19 T6SS functionality and to investigate the mechanisms behind the phenotypes previously observed in vivo. Expression analyses revealed that SPI-19 T6SS core components are expressed and produced under in vitro bacterial growth conditions. However, secretion of the structural/secreted components Hcp1, Hcp2, and VgrG to the culture medium could not be determined, suggesting that additional signals are required for T6SS-dependent secretion of these proteins. In vitro bacterial competition assays failed to demonstrate a role for SPI-19 T6SS in interbacterial killing. In contrast, cell culture experiments with murine and avian macrophages (RAW264.7 and HD11, respectively) revealed production of a green fluorescent protein-tagged version of VgrG soon after Salmonella uptake. Furthermore, infection of RAW264.7 and HD11 macrophages with deletion mutants of SPI-19 or strains with genes encoding specific T6SS core components (clpV and vgrG) revealed that SPI-19 T6SS contributes to S. Gallinarum survival within macrophages at 20 h postuptake. SPI-19 T6SS function was not linked to Salmonella-induced cytotoxicity or cell death of infected macrophages, as has been described for other T6SS. Our data indicate that SPI-19 T6SS corresponds to a novel tool used by Salmonella to survive within host cells. |
| Databáze: | OpenAIRE |
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