title: Rapid Detection of Escherichia coli O157 and Shiga Toxins by Lateral Flow Immunoassays.
abstract: Shiga toxin-producing Escherichia coli O157:H7 (STEC) cause food-borne illness that may be fatal. STEC strains enumerate two types of potent Shiga toxins (Stx1 and Stx2) that are responsible for causing diseases. It is important to detect the E. coli O157 and Shiga toxins in food to prevent outbreak of diseases. We describe the development of two multi-analyte antibody-based lateral flow immunoassays (LFIA); one for the detection of Stx1 and Stx2 and one for the detection of E. coli O157 that may be used simultaneously to detect pathogenic E. coli O157:H7. The LFIA strips were developed by conjugating nano colloidal gold particles with monoclonal antibodies against Stx1 and Stx2 and anti-lipid A antibodies to capture Shiga toxins and O157 antigen, respectively. Our results indicate that the LFIA for Stx is highly specific and detected Stx1 and Stx2 within three hours of induction of STEC with ciprofloxacin at 37 °C. The limit of detection for E. coli O157 LFIA was found to be 10⁵ CFU/mL in ground beef spiked with the pathogen. The LFIAs are rapid, accurate and easy to use and do not require sophisticated equipment or trained personnel. Following the assay, colored bands on the membrane develop for end-point detection. The LFIAs may be used for screening STEC in food and the environment.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA. rxk104@psu.edu.
authors.forename: Robab
authors.initials: R
authors.lastname: Katani
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA. lul17@psu.edu.
authors.forename: Lingling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA. hegdenv@yahoo.com.
authors.forename: Narasimha
authors.initials: N
authors.lastname: Hegde
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA. elr2@psu.edu.
authors.forename: Elisabeth L
authors.initials: EL
authors.lastname: Roberts
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA. vkapur@psu.edu.
authors.forename: Vivek
authors.initials: V
authors.lastname: Kapur
authors.affiliation: Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, 115 Henning Building, University Park, PA 16802, USA. rcd3@psu.edu.
authors.forename: Chitrita
authors.initials: C
authors.lastname: DebRoy
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry / Q000276:immunology; D058491:Bacterial Load; D019453:Escherichia coli O157 / Q000276:immunology / Q000302:isolation & purification*; D006046:Gold / Q000737:chemistry; D007118:Immunoassay; D053768:Metal Nanoparticles / Q000737:chemistry; D022622:Shiga Toxin 1 / Q000032:analysis* / Q000276:immunology; D022641:Shiga Toxin 2 / Q000032:analysis* / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; D006046:Gold
keywords: E. coli O157; STEC; Shiga toxin; Stx; colloidal gold; food safety; lateral flow immunoassay (LFIA)