Article
DNA adenine methylase mutants of Salmonella typhimurium show defects in protein secretion, cell invasion, and M cell cytotoxicity
Author/s | García-Del Portillo, Francisco
Pucciarelli, María Graciela Casadesús Pursals, Josep |
Department | Universidad de Sevilla. Departamento de Genética |
Publication Date | 1999 |
Deposit Date | 2018-01-26 |
Published in |
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Abstract | Mutants of Salmonella typhimurium lacking DNA adenine methylase are attenuated for virulence in BALB/c mice. LD50 values of a DNA adenine methylation (Dam)- mutant are at least 103- to 104-fold higher than those of the ... Mutants of Salmonella typhimurium lacking DNA adenine methylase are attenuated for virulence in BALB/c mice. LD50 values of a DNA adenine methylation (Dam)- mutant are at least 103- to 104-fold higher than those of the parental strain when administrated by oral or intraperitoneal routes. Dam- mutants are unable to proliferate in target organs but persist in low numbers in these locations. Efficient protection to challenge with the virulent parental strain is observed in mice infected with a Dam- mutant. Use of the ileal loop assay shows that Dam- mutants are less cytotoxic to M cells and fail to invade enterocytes. In the tissue culture model, lack of DNA adenine methylation causes reduced ability to invade nonphagocytic cells. In contrast, no effect is observed either in intracellular proliferation within nonphagocytic cells or in survival within macrophages. The invasion defect of Dam- mutants is correlated with a distinct pattern of secreted proteins, which is observed in both PhoP+ and PhoP- backgrounds. Altogether, our observations suggest a multifactorial role of Dam methylation in Salmonella virulence. |
Funding agencies | Ministerio de Educación y Ciencia (MEC). España Comunidad Autónoma de Madrid |
Citation | García-Del Portillo, F., Pucciarelli, M.G. y Casadesus Pursals, J. (1999). DNA adenine methylase mutants of Salmonella typhimurium show defects in protein secretion, cell invasion, and M cell cytotoxicity. Proceedings of the National Academy of Sciences of the United States of America, 96 (20), 11578-11583. |
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