Seyed Ali Mirhosseini - Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Hamid Sedighian - Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Jafar Amani - Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
Elham Behzadi - Department of Microbiology, College of Basic Sciences, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran.
Abbas Ali Imani Fooladi - Applied Microbiology Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran

Introduction: Heat-labile enterotoxin (LT) of Enterotoxigenic Escherichia coli (ETEC) and Shiga toxin (Stx) of Shigella dysenteriae serotype ۱ are two important toxins of food-borne pathogens associated with diarrheal disease. These agents have been recognized as the first leading causes of neonatal diarrhea and the Hemolytic-Uremic Syndrome (HUS). These toxins have two subunits, A and B, that B subunit can be used as a diagnostic tool.Materials and Methods: In this study, the LTB and STXB genes were amplified by using the Polymerase Chain Reaction (PCR) technique and cloned into the prokaryotic expression vector. Following the expression of recombinant LTB and STXB proteins, mouse polyclonal anti recombinant LT enterotoxin and Shiga toxin B subunits were produced for immunological detection. An Enzyme-Linked Immunosorbent Assay (ELISA) was developed for detecting toxins using clinical samples.Results: Our results showed that the competitive ELISA has high specificity. In addition, the detection limits for LTB and STXB were ۲۰ ng and ۹۰ ng, respectively.Conclusions: Our findings revealed that the B subunit of LT and STX can be of a great help in detecting these agents. 

Heat-Labile Enterotoxin (LT), Shiga Toxin, B Subunits, polyclonal antibodies, ELISA