Investigation the Shigella serotypes invasive cells isolated from patients with diarrhea in HEp-2 cell culture

Diarrhea is one of the most prevalent cause of children`s death in developing countries. Gastrointestinal diseases are the cause of much death among the children under the age of 5 every year. In this study the invasiveness character of Shigella strains was investigated by HEp-2cell cell culture technique. In this descriptive study، 280 rectal swabs (140 with dysentery and 140 watery diarrhea) from patients suffering from diarrhea before using any antibiotic and 140 from healthy people as control group were collected. These specimens were cultured in Hektoen and XLD agar as selective and differential media، then after 24 hours incubation in 37˚C their morphology were studied and finally the isolates were confirmed with biochemical tests. Shigella spp strains consist of 20 collection strains were used for consideration of invasiveness in Shigella. Antibiotic typing also performed according to CLSI instructions. Thirty six strains of Shigella (8. 6%) were isolated from thesamples under the study. Most strains isolated from patients، were Shigella flexneri isolated with 16. Our study on HEp-2 cell cultures showed that only 14 (9 isolates، 5 collections) had invasive properties of Shigella strains. The results show that firstly all Shigella isolates are not capable of invading intestinal epithelial cells; Secondly invasion is not a constant attitude and it would not go away by time