Tn5-tagged invasion plasmid DNA (pWR110) from Shigella flexneri serotype 5 (strain M90T) was cloned into the expression vector lambda gt11. Recombinant phage (lambda gt11Sfl) expressing pWR110-encoded polypeptide antigens were identified by using rabbit antisera directed against S. flexneri M90T invasion plasmid antigens. Antigens encoded by lambda gt11Sfl recombinant phage were characterized b...

This study was carried out to determine the antimicrobial susceptibility patterns of 584 Shigella flexneri isolated from diarrheal patients admitted in hospitals in Azad Kashmir Pakistan and to evaluate their changing trends against twenty antibiotics. The isolates showed highest resistance against penicillin followed by carbenicillin, ampicillin, tetracycline, erythromycin, ceftizoxime, kanamy...

Shigella flexneri contact with enterocytes induces a burst of protein secretion via its type III secretion apparatus (TTSA) as an initial step in cellular invasion. We have previously reported that IpaD is positioned at the TTSA needle tip (M. Espina et al., Infect. Immuno. 74:4391-4400, 2006). From this position, IpaD senses small molecules in the environment to control the presentation of Ipa...

Shigella flexneri, the causitive agent of bacillary dysentery, has been shown to disseminate in colonic epithelial cells via protrusions that extend from infected cells and are endocytosed by adjacent cells. This phenomenon occurs in the region of the eukaryotic cell's adherens junctions and is inhibited by pharmacological reagents or host cell mutations that completely disrupt the junctional c...

Epithelial cell infection by Shigella flexneri 2a was studied in an in vitro model system. Using the Henle 407 human intestinal epithelial cell line as host cells, a standardized experimental protocol which allowed quantitative measurement of infection was developed. Intravellular residence of infecting organisms was confirmed by indirect fluorescent-antibody staining of unfixed and methanol-fi...

The serogroup distribution and antimicrobial susceptibility patterns of Shigella isolates obtained from stool specimens of persons with acute diarrhoea in community-based studies from southern Trinidad during 1997-2006 were reviewed. Of the 5,187 stool specimens, 392 (8%) were positive for Shigella organisms. From these 392 isolates, 88.8% were recovered from children aged >0-10 year(s). Shigel...

The differentiation between Shigella subspecies, and the phylogenetic position of Shigella clones within Escherichia coli clones was determined by analysis of restriction fragment length polymorphisms of rDNA (ribotyping). Seventy-five Shigella strains belonging to the four subspecies and 13 enteroinvasive E. coli (EIEC) strains were compared with the 72 E. coli strains of the ECOR collection, ...

Shigella flexneri is an intracellular pathogen that can escape from phagosomes to reach the cytosol, and polymerize the host actin cytoskeleton to promote its motility and dissemination. New work has shown that proteins involved in actin-based motility are also linked to autophagy, an intracellular degradation process crucial for cell autonomous immunity. Strikingly, host cells may prevent acti...

A fractional factorial design was used to measure the effects and interactions of temperature (12-37 degrees C), initial pH (5.5-7.5), NaCl (0.5-4.0%) and NaNO2 (0-1000 ppm) on the anaerobic growth kinetics of Shigella flexneri in Brain-Heart Infusion broth. Anaerobic conditions were established by flushing the culture flasks with N2. A total of 375 cultures representing 124 variable combinatio...

One of the chromosomal segments associated with virulence in Shigella flexneri encodes the production of aerobactin and the synthesis of an iron-regulated 76-kilodalton outer membrane protein believed to be the ferric-aerobactin receptor. However, S. flexneri expressing this putative aerobactin receptor, which is slightly larger than that encoded by pColV, is insensitive to the killing action o...