Field and Clinical Applications of Advanced Bacteriophage-Based Detection of Yersinia pestis

Bacteriophage lysis tests remain important tools for Yersinia pestis detection and plague diagnostics, but they usually include the isolation of pure Y. pestis culture that requires about 3 days to accomplish. Recently, we have developed a rapid and sensitive alternative assay based on quantitative real-time PCR (qPCR) monitoring of the amplification of reporter plague diagnostic phages φA1122 and L-413C. In this work, we tested a possibility of field application of this method using JBAIDS platform, a portable field-deployable instrument developed by Idaho Technology Inc. The phage detection limit (and thus the limit of Y. pestis indirect detection) achieved with the portable JBAIDS system was identical to that obtained using a full-sized LightCycler 2.0 real-time PCR instrument (Roche). We also explored potential clinical and epizootiological applications of the qPCR-based bacteriophage detection of Y. pestis using simulated sheep serum and mouse tissue (spleen, liver) samples. Satisfactory levels of sensitivity were observed when using diluted spleen suspensions and most promising results were obtained with diluted and whole serum.