Development of a cost-effective LAMP method for screening and monitoring enteropathogenic Yersinia in environmental matrices.

BACKGROUND

Closely related bacterial pathogens, Yersinia pseudotuberculosis, Yersinia pestis (the plague agent), and Yersinia enterocolitica, reside in environmental ecosystems that may be the source of infection for animals and humans. Reliable field-deployable detection methods are essential for monitoring these pathogens in natural ecosystems.

METHODS

A colorimetric loop-mediated isothermal amplification (LAMP) assay targeting the mglB gene (shared by Y. pseudotuberculosis and Y. pestis) and the chbG gene (specific to Y. enterocolitica) was developed. Specificity was evaluated using six Yersinia isolates, and sensitivity was determined from serial dilutions of Y. enterocolitica and Y. pseudotuberculosis cultures. The optimized LAMP assays were then applied to 28 environmental samples collected from two plague-endemic regions and one plague-free region in Algeria, and results were compared with those obtained using conventional PCR.

RESULTS

No Yersinia species were detected in any environmental samples by either LAMP or PCR. However, both assays successfully detected 1.5 × 108 CFU/mL of Y. pseudotuberculosis or Y. enterocolitica when samples were artificially spiked, confirming that no environmental inhibitors interfered with detection.

CONCLUSION

The reported LAMP assays show characteristics that make them well suited for field deployment in the environmental monitoring of Yersinia species of medical and veterinary importance.