Stg fimbrial operon from S. Typhi STH2370 contributes to association and cell disruption of epithelial and macrophage-like cells
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Archivos
Fecha
2015
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Sociedad de Biología de Chile
Nombre de Curso
Licencia CC
Licencia CC
Resumen
BACKGROUND: Salmonella enterica serovar Typhi (S. Typhi) stg operon, encoding a chaperone/usher fimbria (CU), contributes to an increased adherence to human epithelial cells. However, one report suggests that the presence of the Stg fimbria impairs the monocyte-bacteria association, as deduced by the lower level of invasion to macrophage-like cells observed when the stg fimbrial cluster was overexpressed. Nevertheless, since other CU fimbrial structures increase the entry of S. Typhi into macrophages, and considering that transcriptomic analyses revealed that stg operon is indeed expressed in macrophages, we reassessed the role of the stg operon in the interaction between S. Typhi strain STH2370 and human cells, including macrophage-like cells and mononuclear cells directly taken from human peripheral blood.
RESULTS: We compared S. Typhi STH2370 WT, a Chilean clinical strain, and the S. Typhi STH2370 Astg mutant with respect to association and invasion using epithelial and macrophage-like cells. We observed that deletion of stg operon reduced the association and invasion of S. Typhi, in both cellular types. The presence of the cloned stg operon restored the WT phenotype in all the cases. Moreover, we compared Salmonella enterica sv. Typhimurium 14028s (S. Typhimurium, a serovar lacking stg operon) and S. Typhimurium heterologously expressing S. Typhi stg. We found that the latter presents an increased cell disruption of polarized epithelial cells and an increased association in both epithelial and macrophage-like cells.
CONCLUSIONS: S. Typhi stg operon encodes a functional adhesin that participates in the interaction bacteria-eukary-otic cells, including epithelial cells and macrophages-like cells. The phenotypes associated to stg operon include increased association and consequent invasion in bacteria-eukaryotic cells, and cell disruption.
Notas
Indexación: Web of Science; Scielo.
Palabras clave
Salmonella Typhi, stg, Fimbriae, Adherence, Association bacteria-eukaryotic cells
Citación
Biol. Res. vol.48 Santiago 2015