Development of monoclonal antibodies and immunoassays for sensitive and specific detection of Shiga toxin Stx2f

PLoS One. 2013 Sep 17;8(9):e76563. doi: 10.1371/journal.pone.0076563. eCollection 2013.


Background: Shiga toxin 2 (Stx2) is a major virulence factor in gastrointestinal diseases caused by Escherichia coli. Although Stx2a (prototypical Stx2) is well-studied, all seven subtypes of Stx2 have been associated with disease in mammals. Several subtypes of Stx2, including Stx2f, are difficult to detect immunologically.

Methods and findings: Four novel monoclonal antibodies (mAbs) against the Stx2f subtype were produced and characterized. These mAbs react exclusively to the Stx2f A subunit, and do not cross-react with other subtypes of Stx2. A Stx2f-specific sandwich ELISA was established and a limit of detection of 0.123 ng/mL was obtained using one pair of the mAbs. The receptor preference of Stx2f was confirmed using this sandwich ELISA. Three out of four mAbs can partially neutralize the toxicity of Stx2f in a cell-based assay. These mAbs were also demonstrated to be highly specific and reactive when applied to colony immunoblot assays.

Conclusions: Novel mAbs specific to Stx2f were developed for the first time, providing new assets for the STEC community. Immunoassays with improved sensitivity and specificity will be useful for the detection of Stx2f present in food, environmental, and clinical samples.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / biosynthesis
  • Antibodies, Monoclonal / immunology*
  • Antibodies, Neutralizing / immunology
  • Antibody Specificity / immunology
  • Cell Line
  • Chickens
  • Enzyme-Linked Immunosorbent Assay / standards
  • Escherichia coli / immunology
  • Escherichia coli / metabolism
  • Humans
  • Immunoassay / methods*
  • Immunoassay / standards*
  • Mice
  • Sensitivity and Specificity
  • Shiga Toxin 2 / immunology*


  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Shiga Toxin 2

Grant support

This research was supported by USDA-ARS National Program NP108, CRIS project 5325-42000-048-00D. The U.S. Department of Agriculture is an equal opportunity provider and employer. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.