Duplex lateral flow immunoassay (LFIA) for detection of Yersinia pestis in environmental samples and suspicious substances
Résumé
Yersinia pestis (Y. pestis), the causative agent of the plague disease, has long been considered as a potent weapon of biological warfare. The rapid detection of the bioterrorist agent in environment or suspicious substances is essential to protect the civil population in case of malicious act. In this context, several dipsticks for rapid detection of Y. pestis have been developed and are now available on the market. These tests target almost exclusively the fraction capsular antigen 1 (F1) expressed mostly at 37°C (in course of infection or in-vitro culture), and are thus not always adapted for detection of Y. pestis from environmental source.
For this reason, we developed a duplex lateral flow immunoassay (LFIA) combining the detection of F1 and an antigen expressed independently of the temperature. An industrial pre-batch was produced and its analytical sensitivity was assessed using bacteria grown at temperature in the range of 20°C to 37°C. The specificity was checked using various Y. pestis strains, strains of closely related species and more distantly related species. All ten Y. pestis strains grown at 30°C or 37°C were detected positive, as well as some Y. pseudotuberculosis strains but with a lower signal intensity. Other species were tested negative. Moreover, we investigated the impact of various environmental matrices and suspicious substances on the field. Most of them had no effect on the observed results.