TY - JOUR
T1 - Stg fimbrial operon from S. Typhi STH2370 contributes to association and cell disruption of epithelial and macrophage ‑ Like cells
AU - Berrocal, Liliana
AU - Fuentes, Juan A.
AU - Trombert, A. Nicole
AU - Jofré, Matías R.
AU - Villagra, Nicolás A.
AU - Valenzuela, Luis M.
AU - Mora, Guido C.
N1 - Funding Information:
This work was supported by National Fund for Development of Science and Technology (FONDECYT), Government of Chile, grants 1151393 (G.C.M), 11121506 (J.A.F.), and Núcleo UNAB 22-12/N (G.C.M. and J.A.F.). L.B. was supported by UNAB Grant DI-11-06/I.
Publisher Copyright:
© 2015 Berrocal et al.
PY - 2015
Y1 - 2015
N2 - 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 Δstg 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—eukaryotic 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.
AB - 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 Δstg 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—eukaryotic 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.
KW - Adherence
KW - Association bacteria—eukaryotic cells
KW - Fimbriae
KW - Salmonella Typhi
KW - Stg
UR - http://www.scopus.com/inward/record.url?scp=84941363199&partnerID=8YFLogxK
U2 - 10.1186/s40659-015-0024-9
DO - 10.1186/s40659-015-0024-9
M3 - Article
C2 - 26149381
AN - SCOPUS:84941363199
SN - 0716-9760
VL - 48
JO - Archivos de Biologia y Medicina Experimentales
JF - Archivos de Biologia y Medicina Experimentales
M1 - 34
ER -