|
|
||||||||
Molecular Diagnostics and Genetics |
1 Diagnostic Systems Division, The United States Army Medical Research Institute of Infectious Diseases, Fort Detrick, Frederick, MD.
2 Battelle, Columbus, OH.
3 National Biodefense Analysis and Countermeasures Center, Department of Homeland Security, Frederick, MD.
aAddress correspondence to this author at: The United States Army Medical Research Institute of Infectious Diseases, 1425 Porter St., Fort Detrick, Frederick, MD 21702-5011. Fax 301-619-2492; e-mail David.Kulesh{at}amedd.army.mil.
Background: Yersinia pestis, the causative agent of the zoonotic infection plague, is a major concern as a potential bioweapon. Current real-time PCR assays used for Y. pestis detection are based on plasmid targets, some of which may generate false-positive results.
Methods: Using the yp48 gene of Y. pestis, we designed and tested 2 real-time TaqMan® minor groove binder (MGB) assays that allowed us to use chromosomal genes as both confirmatory and differential targets for Y. pestis. We also designed several additional assays using both Simple-Probe® and MGB EclipseTM probe technologies for the selective differentiation of Yersinia pseudotuberculosis from Y. pestis. These assays were designed around a 25-bp insertion site recently identified within the yp48 gene of Y. pseudotuberculosis.
Results: The Y. pestis-specific assay distinguished this bacterium from other Yersinia species but had unacceptable low-level detection of Y. pseudotuberculosis, a closely related species. Simple-Probe and MGB Eclipse probes specific for the 25-bp insertion detected only Y. pseudotuberculosis DNA. Probes that spanned the deletion site detected both Y. pestis and Y. pseudotuberculosis DNA, and the 2 species were clearly differentiated by a post-PCR melting temperature (Tm) analysis. The Simple-Probe assay produced an almost 7 °C Tm difference and the MGB Eclipse probe a slightly more than 4 °C difference.
Conclusions: Our method clearly discriminates Y. pestis DNA from all other Yersinia species tested and from the closely related Y. pseudotuberculosis. These chromosomal assays are important both to verify the presence of Y. pestis based on a chromosomal target and to easily distinguish it from Y. pseudotuberculosis.
The following articles in journals at HighWire Press have cited this article:
![]() |
E. S. Gabitzsch, R. Vera-Tudela, R. J. Eisen, S. W. Bearden, K. L. Gage, and N. S. Zeidner Development of a Real-time Quantitative PCR Assay to Enumerate Yersinia pestis in Fleas Am J Trop Med Hyg, July 1, 2008; 79(1): 99 - 101. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Satterfield, D. A. Kulesh, D. A. Norwood, L. P. Wasieloski Jr, M. R. Caplan, and J. A.A. West Tentacle ProbesTM: Differentiation of Difficult Single-Nucleotide Polymorphisms and Deletions by Presence or Absence of a Signal in Real-Time PCR Clin. Chem., December 1, 2007; 53(12): 2042 - 2050. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. C. Satterfield, J. A.A. West, and M. R. Caplan Tentacle probes: eliminating false positives without sacrificing sensitivity Nucleic Acids Res., May 21, 2007; (2007) gkm113v1. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. G. Herrmann, J. D. Durtschi, L. K. Bromley, C. T. Wittwer, and K. V. Voelkerding Amplicon DNA Melting Analysis for Mutation Scanning and Genotyping: Cross-Platform Comparison of Instruments and Dyes Clin. Chem., March 1, 2006; 52(3): 494 - 503. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |