The innate and adaptive immune responses of dendritic cells (DCs) to enteroinvasive Escherichia coli (EIEC) infection were compared with DC responses to Shigella flexneri infection. EIEC triggered DCs to produce interleukin (IL)-10, IL-12 and tumour necrosis factor (TNF)-α, whereas S. flexneri induced only the production of TNF-α. Unlike S. flexneri, EIEC strongly increased the expression of to...

The primary step in the pathogenesis of bacillary dysentery is the penetration of intestinal epithelial cells by shigellae. Lacking this capacity, Shigella flexneri becomes avirulent. By means of intergeneric conjugation between various Escherichia coli K-12 Hfr strains and S. flexneri 2a virulent recipients and by reciprocal transduction analysis with phage P1 vir, we established a locus on th...

Considerable amounts of immunoglobulin G (IgG) antibody appeared in hyperimmune rabbit serum at a late period during a course of immunization with several injections of Shigella flexneri O antigens. High yields of IgG antibody possessing homogenous specificity could be fractionated from crude gamma-globulin solution on a diethylaminoethyl-Sephadex column with 0.02 m phosphate buffer (pH 6.6) co...

A previously identified Shigella flexneri serotype 2a strain was responsible for an outbreak of shigellosis in a Taiwan township in August 1996. In order to find the relationship between this outbreak strain and subsequent Shigella infections in the area, 59, 47, 35, and 20 Shigella isolates recovered in 1997, 1998, 1999, and 2000, respectively, were collected and typed by serological and pulse...

Shigella flexneri is divided into 13 serotypes based on the combination of antigenic determinants present in the O-antigen. A new O-antigen modification with phosphoethanolamine has been identified. The presence of this antigenic determinant (called E1037) is recognized by monoclonal antibody MASF IV-1. Given the increasing incidence of these new variants and the difficulty in supplying the mon...

The glutamate-dependent acid-resistance system is the most effective acid tolerance pathway in Shigella, allowing survival in extremely acidic environments. However, the regulation of this system in Shigella remains elusive. In the current study, we identified significant differences in the levels of glutamate decarboxylase between three Shigella flexneri strains with different levels of acid r...

diarrheal disease is one of the main causes of death in developing countries. this study was performed to the prevalence of bacterial causes of diarrhea in patients admitted to the military hospitals and imam khomeini medical center hospital. this cross-sectional study was conducted in a period of 9 months from june 2014 to february 2015, 435 non-duplicative diarrheal stool samples were collect...

Shigella flexneri is the major cause of shigellosis in developing countries. A new S. flexneri serotype, Xv, appeared in 2000 and replaced serotype 2a as the most prevalent serotype in China. Serotype Xv is a variant of serotype X, with phosphoethanolamine modification of its O antigen mediated by a plasmid that contained the opt gene. Serotype Xv isolates belong to sequence type 91 (ST91). In ...

Shigella flexneri, the causative agent of bacillary dysentery, injects invasin proteins through a type III secretion apparatus upon contacting the host cell, which triggers pathogen internalization. The invasin IpaA is essential for S. flexneri pathogenesis and binds to the cytoskeletal protein vinculin to facilitate host cell entry. We report that IpaA harbors two vinculin-binding sites (VBSs)...

BACKGROUND AND OBJECTIVES Shigellosis is an acute gastroenteritis that is one of the most common causes of morbidity and mortality in children with diarrhea in developing countries. The purpose of this study was to describe the distribution of Shigella serogroups and serotypes and their antibacterial drug resistance profiles. MATERIALS AND METHODS Fecal samples of all children suffering from ...