A polyclonal antibody based immunoassay detects seven subtypes of Shiga toxin 2 produced by Escherichia coli in human and environmental samples.

Autor: Xiaohua He, Stephanie Patfield, Robert Hnasko, Reuven Rasooly, Robert E Mandrell
Jazyk: angličtina
Rok vydání: 2013
Předmět:
Zdroj: PLoS ONE, Vol 8, Iss 10, p e76368 (2013)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0076368
Popis: BACKGROUND: Shiga toxin-producing Escherichia coli (STEC) are frequent causes of severe human diseases ranging from diarrhea to hemolytic uremic syndrome. The existing strategy for detection of STEC relies on the unique sorbitol-negative fermentation property of the O157 strains, the most commonly identified serotype has been E. coli O157. It is becoming increasingly evident, however, that numerous non-O157 STEC serotypes also cause outbreaks and severe illnesses. It is necessary to have new methods that are capable of detecting all STEC strains. METHODS AND FINDINGS: Here we describe the development of a sandwich ELISA assay for detecting both O157 and non-O157 STECs by incorporating a novel polyclonal antibody (pAb) against Stx2. The newly established immunoassay was capable of detecting Stx2a spiked in environmental samples with a limit of detection between 10 and 100 pg/mL in soil and between 100 and 500 pg/mL in feces. When applied to 36 bacterial strains isolated from human and environmental samples, this assay detected Stx2 in all strains that were confirmed to be stx2-positive by real-time PCR, demonstrating a 100% sensitivity and specificity. CONCLUSIONS: The sandwich ELISA developed in this study will enable any competent laboratory to identify and characterize Stx2-producing O157 and non-O157 strains in human and environmental samples, resulting in rapid diagnosis and patient care. The results of epitope mapping from this study will be useful for further development of a peptide-based antibody and vaccine.
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