polymerase chain reaction method for the rapid detection of virulent shigella spp.

bacillary dysentery, or shigellosis, is a disease of humans in which the colonic epithelium is invaded by bacteria and subjected to inflammatory destruction. the aim of this study was to develop a polymerase chain reaction(pcr) test for detection of virulent shigella spp.. for this purpose, the primers were designed to amplify a 526-bp internal region of the shigella spp. icsa gene, which encodes icsa (intracellular spread)/virg protein, a 116-kda surface exposed outer membrane protein that mediates actin polymerization to aid bacterial movement inside the cell. the use of pcr to amplify a specific icsa gene fragment serves as a highly specific and sensitive method to detect virulent bacteria of the genus shigella. specific dna band was obtained by using isolated plasmid dna of shigella and a bacterial suspension. amplification of extracted dna from all other genera of the family enterobacteriaceae and various other gram-positive bacteria yielded negative results. therefore this pcr method, can serve as a routine protocol for detecting and identifying virulent shigella spp. from clinical samples.