title: Enhanced Type III Secretion System Expression of Atypical Shigella flexneri II:(3)4,7(8).
abstract: OBJECTIVE
  We aimed at evaluating the virulence of atypical Shigella flexneri II:(3)4,7(8) by DNA microarray and invasion assay.
  
  
  METHODS
  We used a customized S. flexneri DNA microarray to analyze an atypical S. flexneri II:(3)4,7(8) gene expression profile and compared it with that of the S. flexneri 2b strain.
  
  
  RESULTS
  Approximately one-quarter of the atypical S. flexneri II:(3)4,7(8) strain genes showed significantly altered expression profiles; 344 genes were more than two-fold upregulated, and 442 genes were more than 0.5-fold downregulated. The upregulated genes were divided into the category of 21 clusters of orthologous groups (COGs), and the "not in COGs" category included 170 genes. This category had virulence plasmid genes, including the ipa-mxi-spa genes required for invasion of colorectal epithelium (type III secretion system). Quantitative reverse-transcription polymerase chain reaction results also showed the same pattern in two more atypical S. flexneri II:(3)4,7(8) strains. Atypical S. flexneri II:(3)4,7(8) showed four times increased invasion activity in Caco-2 cells than that of typical strains.
  
  
  CONCLUSIONS
  Our results provide the intracellularly regulated genes that may be important for adaptation and growth strategies of this atypical S. flexneri.
authors.affiliation: Division of Enteric Bacterial Infections, Korea National Institute of Health, Osong, Korea.
authors.forename: Sahyun
authors.initials: S
authors.lastname: Hong
authors.forename: Injun
authors.initials: I
authors.lastname: Cha
authors.forename: Nan-Ok
authors.initials: NO
authors.lastname: Kim
authors.forename: Seong-Han
authors.initials: SH
authors.lastname: Kim
authors.forename: Kyung-Tae
authors.initials: KT
authors.lastname: Jung
authors.forename: Je-Hee
authors.initials: JH
authors.lastname: Lee
authors.forename: Dong-Wook
authors.initials: DW
authors.lastname: Kim
authors.forename: Mi-Sun
authors.initials: MS
authors.lastname: Park
authors.forename: Yeon-Ho
authors.initials: YH
authors.lastname: Kang
keywords: Shigella; atypical; microarray